WLI-MVS_IB.pdf

IB021

Instructions for Installation, Operation, and Maintenance of Type MVS (Previously WLI) Metal Enclosed Switchgear:

4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV Instructional Booklet 02006E For more information visit: www.eatonelectrical.com New Information

Description Page

1. Introduction

2. Receiving, Handling, and Storage

3. Installation

4. Operation

5. Maintenance

6. Duplex Switchgear Configuration

7. Motor Operation

8. Electromechanical Stored Energy Release

(Shunt Trip)

9. MVS Switchgear Bolt Tightness for

Bus Connections and Connections to Switch Terminal Pads

10. Common Renewal Parts

Indoor MVS Switchgear Assembly Outdoor MVS Switchgear Assembly

Instructions for Installation, Operation, and Maintenance of Type MVS (Previously WLI) Metal Enclosed

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 2 Effective: April 2006 Section 1: Introduction Read and understand these instructions before attempt-ing any installation, operation, or maintenance of this switchgear.

1.1 Purpose

This instruction book is expressly intended to cover the installation, operation, and maintenance of type Medium Voltage Switch (MVS), previously known as the West-inghouse Load Interrupter (WLI) metal enclosed switch-gear. It does not purport to cover all possible contingencies, variations, and details that may arise dur-ing installation, operation, or maintenance of this equip-ment.

If further information is desired by the purchaser regard-ing this particular installation or application information, contact the local Eaton Electrical, Inc. sales office, see Eaton Electrical, Inc. Consulting Application Guide, and review the appropriate industry standards.

1.2 Basic Description and Application

A type MVS (previously WLI) metal enclosed switchgear assembly vertical section consists of an air insulated, three-pole, gang-operated, quick-make, quick-break, load interrupter switch in a floor mounted metal enclosure. It can be applied in combination with power fuses and many other protective devices to provide safe, economi-cal switching and circuit protection where infrequent dis-connecting means is required.

1.3 Switchgear Identification

A nameplate is located inside the small access door of each type MVS switchgear vertical section (see Fig. 1).

Contained on this nameplate are the Eaton Electrical, Inc. master parts list number and all the necessary switchgear ratings. This information should be given to the Eaton Electrical, Inc. sales office if a question should arise concerning the switchgear or if renewal parts are required. This information is sufficient for Eaton Electri-cal, Inc. to find the manufacturing information for the switchgear.

Figure 1. Typical Nameplate.

The switch rating nameplate is on the switch mechanism cover. This nameplate is readily visible when the main enclosure door is opened. This nameplate contains all of the switch’s ratings and style number.

symmetrical amperes; volts maximum.

ratings when fuses are mounted in this vertical section.

See separate label inside for fuse continuous current capable of delivering not more than RMS

This switchgear vertical section is suitable for use on a circuit of industry standards IEEE C37.20.3 and ANSI C37.57

Type Switchgear Assemblies meet the requirements

Short Time (2 Sec., Sym)

Momentary RMS Asym

Continuous:

Maximum Continuous

Master P.L.:

GO & It:

Section No. Of

Date:

3 Phase 60 Hz.

kV BIL:Operating Volts:

Mfd. At:

Encl. Category:

Enclosure Type:

1A33788H01

Type:

Instructions For more information visit: www.eatonelectrical.com IB02102006E

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 3 Figure 2. Switch Nameplate.

1.4 Safety Features

Type MVS load interrupter switchgear has several built-in features to reduce hazards and to provide proper operating sequences.

1. A door interlock prevents opening the enclosure front door while the switch is in the “Closed” posi-tion.

2. A switch interlock prevents manual operation of the handle mechanism with the door open.

3. A viewing window is provided to visually verify the switch contact position.

4. Facility is provided for padlocking the switch in the “Open” or “Closed” position.

5. Facilities are provided for padlocking the door han-dles closed.

6. Mechanical indicators show whether the switch mechanism is “Open” or “Closed”.

7. Key interlocks, when provided, force a sequence of operation.

1.5 Safe Practices

Only qualified electrical workers with training and expe-rience on high voltage circuits should be permitted to work on this equipment. They should be familiar with the work to be performed, the safety equipment required, and hazards involved.

1. Read and fully understand these instructions before attempting any assembly, operation, or maintenance of this switchgear.

2. Disconnect all power sources before making any adjustments or performing maintenance.

3. After opening the switch and before opening the door, use the viewing window to insure that all three switch blades are open. If necessary, use a flash-light to verify all three contacts are open.

WARNING

EXCEEDING THE NAMEPLATE RATINGS OF MVS

SWITCHGEAR COULD CAUSE PROPERTY DAMAGE,

SEVERE INJURY, OR DEATH.

MVS SWITCHGEAR MUST BE OPERATED WITHIN ITS

NAME-PLATED RATINGS.

Maximum

3 Phase 60 Hz

Fault Close and Momentary, Continuous and Load Break

Asymmetrical

(2 seconds)

Replacement fuses shall be of the same manufacture, type, and interrupting rating.

IEEE C37.20.4 ANSI C37.58

R

Instructions

Mfd At:

Fuse Type

Short-Time

BIL

1A33788H02

ANSI C37.22

Style

Date

Type

Fused Fault Close, Asymmetrical CAUTION

OPERATING AN MVS SWITCH WITH A KEY INTER-

LOCK BOLT EXTENDED WILL RESULT IN EQUIPMENT

DAMAGE AND MAY ALSO EXPOSE THE OPERATOR

TO BODILY INJURY OR DEATH.

THE KEY MUST BE INSERTED INTO THE INTERLOCK

AND ROTATED TO RETRACT THE LOCKING BOLT

BEFORE OPERATING AN MVS SWITCH.

WARNING

EXCEEDING THE NAMEPLATE RATINGS OF MVS

SWITCHGEAR COULD CAUSE PROPERTY DAMAGE,

SEVERE INJURY, OR DEATH.

MVS SWITCHGEAR MUST BE OPERATED WITHIN ITS

NAME-PLATED RATINGS.

IB02102006E For more information visit: www.eatonelectrical.com

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 4 Effective: April 2006

4. Never energize the switch without the arc chutes and barriers installed.

5. Always be sure that all hardware is in place and bolted tightly before putting the switch into opera-tion.

6. Before replacing covers, carefully inspect the bus work and phase barriers to insure that no tools or other objects are accidentally left inside the unit.

1.6 Revision

Effective April, 2006. Supersedes I.L. 31-930-D dated June, 1993.

1.7 Eaton Electrical, Inc. Contact Information

For the location of the nearest Eaton Electrical, Inc.

sales office or distributor, call toll free 1-800-525-2000 or log onto www.eatonelectrical.com.

Section 2: Receiving, Handling, and Storage

2.1 Receiving

A visual inspection - inside and out - should be per-formed immediately upon receipt of the switchgear and before removing it from the truck. Shipping papers should be checked to be sure all boxes or other accom-panying pieces have been received. If any damage or shortages are evident, a claim should be filed at once with the carrier and the nearest Eaton Electrical, Inc.

office notified.

The data nameplate for each switchgear assembly is located inside the mechanism access door. The master parts list number is located on this nameplate and should be given to the Eaton Electrical, Inc. representa-tive whenever identification of the assembly is required.

2.2 Handling

Removable lifting lugs are provided on the top of the MVS structure for insertion of hooks to lift the complete structure. This is the only recommended method of moving the MVS structure.

2.3 Storage

If it is necessary to store the equipment before installa-tion, keep it in a clean, dry location with ample air circu-lation and heat to prevent condensation. Like all electrical apparatus, these units contain insulation that must be protected against dirt and moisture.

Note: Outdoor units may be stored outside ONLY if the roof caps are installed, the space heaters are energized, and any openings are enclosed.

WARNING

THERE ARE SEVERAL INTERLOCKS ON THE

SWITCHES. THEY ARE FOR PERSONNEL AND/OR

EQUIPMENT PROTECTION. UNDER NO CIRCUM-

STANCES SHOULD THEY BE MADE INOPERATIVE

WHEN SWITCH IS IN SERVICE. TO DO SO COULD

CAUSE BODILY INJURY OR PROPERTY DAMAGE.

CAUTION

EXTREME CARE SHOULD BE USED NOT TO DAMAGE

OF DEFORM THE SWITCHGEAR IF OTHER MOVING

METHODS ARE EMPLOYED.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 5 Section 3: Installation Refer to the shipping list for the location of bus, hard-ware, and all other joining and installation material.

3.1 Joining Type MVS Enclosures

3.1.1 Access to MVS Switch Vertical Sections

Containing Switches Each MVS switch is shipped from the factory in the “Closed” position to maintain alignment during shipping and handling. The safety interlocking prevents opening of the door of the vertical section when the switch is closed. In order to gain access to the interior, be sure the switchgear is on a true and level surface. To open a manually operated MVS switch, insert the operating handle and push down. When the switch opens, the door may be opened. If the switch is equipped with an electro-mechanical stored energy release feature, follow the instructions on the instruction label located inside the mechanism access door. If the switch is motor operated, it will function identically to a manually oper-ated switch.

When handling MVS switchgear, be sure the switches are in the “Closed” position. Do not operate MVS switches unless they are setting on true and level sur-faces. The definition of level is the foundation cannot deviate more than ± 0.0125 in. in 36 in. (0.318 mm in

914.4 mm) front to rear, left to right, and diagonally at any point beneath the switchgear.

3.1.2 Identification of Shipping Splits

Refer to the front view drawing. Below this drawing, shipping splits will be identified in relation to group num-bers for each vertical section. Normally, shipping sec-tions will not exceed 154 in. (3911.6 mm) in width.

3.1.3 Procedures for Joining MVS Enclosures at

Shipping Splits Refer to Figure 3 while completing the following proce-dure.

Step 1: Remove the eight (8) 0.375-16 in. bolts from each side sheet.

Step 2: Position the shipping sections next to each other. The eight holes will usually match the holes in the adjacent side sheets but, in some cases, it may be necessary to use of an aligning tool such as a punch to force the structures into alignment.

Step 3: Bolt the side sheets together using the eight (8) bolts removed from one side sheet in Step 1.

Figure 3. Joining MVS Enclosures.

Step 4: Make the main and ground bus connections using splice plates and hardware furnished.

The bus bar is tin or silver-plated. To insure a proper electrical connection, care should be taken to protect the plating from damage. DO NOT use joint compound.

Step 5: Bolted connections should be tightened to the torque values given in Section 9.

3.2 Installation of Roof Caps on Outdoor Units

Roof caps are necessary to complete the roof of all out-door MVS switchgear assemblies. Those not factory installed are shipped in cartons that may be put within one or more of the vertical sections if there is space, or they will be shipped separately.

3.2.1 Roofs Requiring Sealing Compound

The following procedure details the work to be done to install each cap on a caulking compound sealed roof joint.

Step 1: Remove the bolts securing the lifting lugs to the

MVS assembly. Remove the lifting lugs then replace the bolts just removed.

Step 2: Place a roof cap in position and start enough screws (provided loose in a hardware package) to temporarily hold it in place.

CAUTION

CLEANING BUS JOINTS WITH ABRASIVE OR CHEMI-

CAL CLEANSERS MAY REMOVE PLATING. THIS

COULD RESULT IN JOINT OVERHEATING.

WIPE THE BUS JOINTS WITH A CLEAN, DRY CLOTH

TO CLEAN SURFACES.

Cutout

Mounting Bolts

Vertical Section to Left Vertical Section to Right

L of Bus Bar

C

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 6 Effective: April 2006 Step 3: Draw a pencil line down the side(s) on to the roof to mark the edge(s) of the cap on the roof.

Step 4: Remove roof cap and apply a 0.25 in.

(6.35 mm) bead of caulking (provided by Eaton electrical, Inc. with the switch) along the inside edge of the pencil line(s).

Step 5: Hold the edge of the roof cap adjacent to the pencil line, then rotate it over onto the bead(s) of caulk, aligning it with the bolt holes in the roof as the action is completed.

Step 6: Install the supplied bolts and gasketed washers (rubber side towards roof cap) in every bolt hole of roof cap. Tighten the bolts to 5 ft-lbs (6.78 N-m).

Figure 4. Roof Cap Installation.

Step 7: Following instructions on the caulking con-tainer, smooth out any excess caulk along edges of the roof cap.

Step 8: Repeat this procedure until all roof caps have been installed.

For roofs that have edges turned up and formed caps to cover the edges, it is only necessary to place the appro-priate caps over the roof edges and fasten them in place with the appropriate fasteners.

3.3 Connection to Type MVS Switchgear to a

Transformer

3.3.1 Physical Connection

3.3.1.1 Indoor Assemblies, Dry Type, Cast Coil Type, or Liquid Filled Type Transformers

Holes are predrilled in the side of the MVS structure to match the holes provided in the transformer.

3.3.1.2 Outdoor Throat Connection, Liquid Filled

Transformers

Refer to Figure 5 while completing the following proce-dure.

Step 1: Remove the sealing ring flange from the MVS switchgear throat and set it aside.

Step 2: The switch and transformer should be brought together to provide spacing of approximately

0.5 in. (12.7 mm) between the throat flanges.

Step 3: Apply the double-faced adhesive tape supplied with the MVS switchgear to the outside sur-faces of both flanges.

Step 4: Press the felt supplied with the MVS switchgear into place on the adhesive tape. The felt is to seal against the entrance of dust and to prevent transmission of the vibration produced by trans-former resonance to the MVS switchgear.

Step 5: Reinstall sealing ring removed in Step 1.

Figure 5. Transformer Connection to the MVS Switch.

3.3.2 Medium Voltage Electrical Connections

3.3.2.1 Connection by Cable Supplied with the Type

MVS Switch

• Cables are NOT factory pre-cut to the proper length.

The installer MUST cut them to fit.

• Factory cables are unshielded. For 15 kV, 27kV, and 38 kV applications, they must be properly separated from each other, from all grounded metal parts, and from the transformer bushings/terminals of other phases. For 4.76 kV applications, it is only necessary to install the cables so they will not be damaged by sharp edges, points, etc.

• Phasing of the main conductors in type MVS switch-gear conforms to industry standards: that is 1, 2, 3, front to rear, top to bottom, and left to right at the connection points unless otherwise noted on the drawings. The installer is responsible for maintaining the continuity of phasing throughout the system.

• Lugs are provided with the switchgear for terminating cables to the transformer bushings/terminals.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 7

3.3.2.2 Connection by Bus Bar

• Splice plates and hardware are provided with the MVS switchgear. The transformer manufacturer supplies the flexible connector.

• The bus bar is tin or silver-plated. To insure a proper electrical connection, care should be taken to protect the plating from damage. Refer to Section 3.1.3 for details.

3.4 Connections to an Ampgard Medium Voltage

Motor Control Center (MCC) Step 1: Holes are predrilled in the side of the MVS switchgear structure to match the holes pro-vided in the Ampgard MCC. Bolt the MVS switchgear and Ampgard MCC together using the hardware furnished with the MVS switch-gear.

Step 2: Make the bus connections as per Section 3.3.2.2.

3.5 Connections to a Medium Voltage Assembly

(MVA) Metal Clad Switchgear Assembly

3.5.1 Indoor Switchgear

Follow the same procedures outlined in Section 3.4.

3.5.2 Outdoor Switchgear

Step 1: Position the units side by side. The holes in the

MVS side sheet around bus cutout will match holes in metal clad switchgear flange.

Step 2: Press the sponge neoprene gasketing tape, sup-plied with MVS switchgear, onto the flange for the weather-tight seal.

Step 3: Join the enclosures using the bolts supplied with the MVS. The opposite side of the metal clad switchgear flange has nuts welded in place for ease of connection.

Step 4: Make the bus connections as per Section 3.3.2.2.

3.6 Connection of Customer Power Cables

Figures 6 through 15 show the suggested means for connection of the incoming or exiting cables (maximum of two per phase, 500 kcmil) to the MVS switchgear.

The letters in each figure apply to the itemized subjects (A through E) that follow. All necessary materials to perform the cable installation are to be provided by oth-ers unless specifically noted otherwise in the detailed instructions below, or where specifically purchased with the switchgear assembly. To install the incoming and exiting cables, follow these instructions.

A. The Switchgear Terminals For incoming power, the terminals are usually located at the top of the switch in a vertical section.

For outgoing circuits, the terminals are beneath the switch if unfused, or on the fuse mounting if fused.

Each terminal pad has a 2-hole pattern suitable for either a single hole terminal or a terminal with a 2-hole National Electrical Manufacturers Association (NEMA) drilling pattern. The terminal lugs for the cable, if purchased with the switchgear, will be bolted to the switchgear terminals. If the terminal lugs are not there, then they are to be provided by others. The terminals of the switchgear are not suit-able to support the weight of the cable. It will be necessary to support the weight of the cable with the cable support angle discussed in C. below.

B. Cable Electrical Stress Relief Devices The design of MVS switchgear is based upon use of “pre-formed” type electrical stress relief devices such as 3-M Quickterm-II®, Raychem® heat shrink termina-tion systems, etc. The stress relief devices are to be provided by others.

C. Cable Support Channel(s) The cable support channel(s) is not supplied by Eaton Electrical, Inc. unless purchased as a feature at the time of offer. The cable supports may be mounted to suit the geometry of the installation by drilling holes in the switchgear structure to suit. The tamper resistant hardware provided is to anchor the support channel(s) to the structure. Use the regular hardware to fasten the channel(s) to the mounting clips. The means to fasten the cable to this chan-nel(s) is to be provided by others. There are a large number of commercially available cable support devices that can be fastened to this channel(s) to support the cable so the cable weight is not hanging on the switchgear terminals.

D. Lacing Cord or Other Equivalent Materials/Means The cables must be lashed together to restrain the cables if a short circuit should occur. This material is to be provided by others. For large cables and/or cable reverse loops, it may also be necessary to lash the cable bundle(s) to the support channel. The views show this suggested fastening of the cable bundles.

WARNING

FAILURE TO INSTALL THE CABLE SUPPORT MAY

RESULT IN DAMAGE TO THE SWITCHGEAR TERMI-

NALS, WHICH IN TURN MAY RESULT IN MAJOR

EQUIPMENT DAMAGE AND CAUSE SEVERE PER-

SONAL INJURY OR DEATH.

THE CABLE SUPPORT MUST BE INSTALLED AS

INSTRUCTED IN THIS DOCUMENT.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 8 Effective: April 2006

E. Current Transformer(s) The current transformer(s) is to be mounted on the side of the cable support that will physically support the current transformer(s) so it will not slide down onto the stress relief devices. The high voltage cable is to be routed through the current trans-former. The H1 side of each current transformer is to be towards the normal source of electric power.

Each current transformer secondary wiring is termi-nated at a plug. This plug is to be placed in the ter-minal block receptacle to match the phase on which the current transformer is mounted. The switchgear terminals will have phase labeling. The secondary wires are to be fastened to the support channel so they can not fall into high voltage parts.

Figure 6. Bottom Cable Entrance (Energy Source), Rear Access.

Figure 7. Top Cable Entrance (Energy Source), Rear Access.

Figure 8. Unfused Bottom Cable Exit (to Load), Rear Access.

WARNING

FAILURE TO LASH THE CABLES TOGETHER MAY

RESULT IN DAMAGE TO THE SWITCHGEAR, WHICH IN

TURN MAY RESULT IN MAJOR EQUIPMENT DAMAGE

AND CAUSE SEVERE PERSONAL INJURY OR DEATH.

THE CABLE MUST BE LASHED TOGETHER AS

INSTRUCTED IN THIS DOCUMENT.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 9 Figure 9. Unfused Top Cable Exit (to Load), Rear Access.

Figure 10. Top Cable Entrance (Energy Source), Front Access.

Figure 11. Bottom Cable Entrance (Energy Source), Front Access.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 10 Effective: April 2006 Figure 12. Unfused Top Cable Exit (to Load), Front Access.

Figure 13. Unfused Bottom Cable Exit (to Load), Front Access.

Figure 14. Fused Top Cable Exit (to Load), Front Access.

Figure 15. Fused Bottom Cable Exit (to Load), Front Access.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 11

3.7 Field Taping of Electrical Connections

During the following procedures, please refer to Figure 16.

Figure 16. Field Taping of Electrical Connections.

3.7.1 Definitions and Eaton Electrical, Inc. Approved

Materials for Field Insulation Filler: Nashua No. 102 Duct Sealer® or 3M Co. Scotch-fil® or Neer® Duct Seal.

Insulating Tape and Pad: Either 3M Co. Scotch 23® or Scotch 130C®.

Insulating Boot: Molded plastic cover that is put over a joint and fastened in place with wire ties.

Joint: An area to be insulated. This consists of the bare conductor and 1.5 in. (38.1 mm) of any pre-insula-tion next to the bare conductor.

Layer: Insulating tape, 1.0-in. (25.4-mm) wide, wrapped from one end of the joint to the other (or to a pad) so each succeeding turn laps the previous turn by the amount specified in the taping chart.

Overlap: A specified distance measured along the pre-insulation starting from the point where the pre-insula-tion ends and the exposed conductor begins.

Pad: Any insulating tape applied which is wider than

1.0 in. (25.4 mm). Includes a band of tape consisting of one or more turns wrapped directly on top of each other.

Pre-insulation: Any insulation covering (sleeving materi-als such as NORYL®, RAYCHEM®, SCOTCHTITE®, and fluidized epoxy coating) adjacent to an exposed conduc-tor prior to insulating.

3.7.2 Responsibility of Installer

• For incoming or outgoing terminations, these approved materials are not supplied by Eaton Electri-cal, Inc. and must be obtained and installed by others as identified in the definitions in Section 3.7.1.

• For connections involving shipping splits within an MVS switchgear assembly, or connecting to a trans-former, or to an Ampgard MCC, or to a MVA switch-gear assembly, or to a medium voltage bus run, insulating materials will be supplied if necessary by Eaton Electrical, Inc. It is the responsibility of the installer to insulate the connections in accordance with these instructions.

• For a switchgear assembly that does not have contin-uous insulating sleeving on the phase bus conductors and where the dimensions in the Table 1 are not met at field assembled connections, insulation of these connections must be made.

Table 1. Minimum Clearance Chart.

*Example: If the phase-to-phase clearances above for a given rating do not exist, then it is only necessary to insulate the center phase.

WARNING

USE OF SOLVENTS, OILS, JOINT COMPOUNDS, OR

GREASE ON OR NEAR NORYL INSULATION WILL

DESTROY IT.

Pre-Insulation

Insulating Tape

Filler PadLap

1- 1/ 2" (Min.La p)

TYPICAL INSULATING TAPE AND PAD

kV RATING OF THE PHASE-TO-PHASE PHASE-TO-GROUND

MVS SWITCHGEAR in. (mm) in. (mm)

4.76 3.5 (88.9) 3.5 (88.9)

15 6 (152.4) 6 (152.4)

27 8 (203.2) 8 (203.2)

38 10.5 (266.7) 10.5 (266.7)

CAUTION

FAILURE TO INSTALL FIELD INSULATION WHERE NEC-

ESSARY IN ACCORDANCE WITH THESE INSTRUC-

TIONS WILL COMPROMISE THE ELECTRICAL RATINGS

OF THE SWITCHGEAR ASSEMBLY.

INSTALL FIELD INSULATION TO MAINTAIN THE ELEC-

TRICAL RATINGS.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 12 Effective: April 2006

3.7.3 Field Insulation Methods

3.7.3.1 Method 1 - Using an Insulating Boot

Step 1: Clean the area of dirt and foreign matter. Use a clean, dry cloth or, if necessary, dampen slightly with distilled water. Do not use any abrasives or solvents.

Step 2: Place the boot over the joint so it fits in place.

Fasten together with plastic wire ties. Cut off excess ends of plastic wire ties.

3.7.3.2 Method 2 - Using Insulating Tape and Filler

3.7.3.2.1 General

Step 1: Elongate the insulating tape 10 to 25 % during application to insure a smooth, tight fit. On pads, elongate the corners only.

Step 2: Should a tape roll expire during application, start the new role by overlapping the previous end by 1/2 turn.

3.7.3.2.2 Joint - No Hardware

Step 1: Clean the area of dirt and foreign matter. Use a clean, dry cloth or, if necessary, dampen slightly with distilled water. Do not use any abrasives or solvents.

Step 2: Apply one turn of 1.0 in. (25.4 mm) tape so 1/2 of the tape is on the conductor and 1/2 is on the pre-insulation. Overlap the tape ends

1.5 in. (38.1 mm).

Step 3: Apply one layer of insulating tape, lapping as specified in the taping chart below, overlapping any pre-insulation by 1.5 in. (38.1 mm).

3.7.3.2.3 Joint - with Hardware

Step 1: Clean the area of dirt and foreign matter. Use a clean, dry cloth or, if necessary, dampen slightly with distilled water. Do not use any abrasives or solvents.

Step 2: Apply the filler over the bare conductor and hardware to cover and smooth out the sur-face. Blend the contour into pre-insulation sur-faces. Cover the conductors and hardware with at least 0.125 in. (3.18 mm) inch of filler.

Step 3: Apply pad(s) of insulating tape of sufficient width to overlap the pre-insulation by 1.0 in.

(25.4 mm) or more.

Step 4: Apply one layer of insulating tape, lapping as specified in the taping chart, overlapping any pre-insulation or pads by 1.5 in. (38.1 mm).

3.7.4 Factory Installed NORYL® Insulation

Factory installed insulation may be NORYL®, a high-per-formance engineering thermoplastic. It can be irrevers-ibly damaged if it comes in contact with certain chemicals. See Section 5.4 for cleaning procedures.

3.8 Securing MVS Switchgear Assemblies to

Foundations All anchoring hardware and necessary devices are to be supplied by the installer. If the switchgear assembly was purchased for seismic applications, follow the instructions on special drawings provided addressing the anchoring and load bearing requirements in additions to the following two sections.

Table 2. Taping Chart.

WARNING

USE OF SOLVENTS, OILS, JOINT COMPOUNDS, OR

GREASES ON OR NEAR NORYL® INSULATION WILL

DESTROY IT.

CLEAN ONLY WITH WATER OR ISOPROPYL ALCOHOL.

CAUTION

ISOPROPYL ALCOHOL IS FLAMMABLE. PROVIDE ADE-

QUATE VENTILATION AND KEEP AWAY FROM

FLAMES AND OTHER IGNITION SOURCES.

CONSULT YOUR SAFETY DEPARTMENT BEFORE

USING.

MVS kV

RATING

PRE-INSULATION OR PAD OVERLAP

(MINIMUM)

INSULATING TAPE

in. (mm) LAP OF TAPE NO. OF LAYERS NO. OF PADS

4.76 1.5 (38.1) 1/2 1 1

Over 4.76 1.5 (38.1) 2/3 2 2

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 13

3.8.1 Typical Floor Plans

Figures 17 and 18 show floor plans for installing MVS switchgear in typical and seismic applications.

Figure 17. Floor Plan of a Typical Non-seismic MVS

4.76 kV, or 15 kV Switchgear Vertical Section.

Figure 18. Floor Plan of a Typical Seismic MVS 4.76 kV or 15 kV Switchgear Vertical Section.

THE FOUNDATION'S SURFACE SHALL BE LEVEL WITHIN

MINIMUM CLEARANCES IN REAR. LOCAL JURISDICTIONS

MINIMUM CLEARANCES IN FRONT IS THE WIDTH OF THE

MINIMUM CLEARANCES ON SIDE. LOCAL JURISDICTIONS

± 0.0125 INCH IN 36 INCHES [0.318 MM IN 9.14.4 MM]

LEFT TO RIGHT, FRONT TO REAR, AND DIAGONALLY,

AS MEASURED BY A LASER LEVEL AT ANY POINT BENEATH

THE SWITCHGEAR ASSEMBLY.

MAY REQUIRE A LARGER DISTANCE.

JURISDICTIONS MAY REQUIRE A LARGER DISTANCE.

MAY REQUIRE A LARGER CLEARANCE.

DOOR SWING EQUALS UNIT WIDTH AT 90 DEGREES.

LOCATIONS FOR TIE-DOWN CLIPS. PROVISIONS

WIDEST VERTICAL SECTION PLUS ONE INCH. LOCAL

(TYP)

FOR 0.50 INCH [13 MM] ANCHOR BOLTS.

[152]

MIN.

.86 [22]

(TYP)

6.00

[11]

.44

FRONT

TYPICAL ANCHOR

PLAN FOR UNITS

DOOR

MIN.

WIDTH

2 5

30.00

MIN.

[25]

1.37

(TYP)

[35]

1.00

MIN.

[762]

MINIMUM CLEARANCES ON SIDE. LOCAL JURISDICTIONS

MINIMUM CLEARANCES IN FRONT IS THE WIDTH OF THE

MINIMUM CLEARANCES IN REAR. LOCAL JURISDICTIONS

FOR 0.50 INCH [13 MM] ANCHOR BOLTS.

(TYP)

WIDEST VERTICAL SECTION PLUS ONE INCH. LOCAL

LOCATIONS FOR TIE-DOWN CLIPS. PROVISIONS

DOOR SWING EQUALS UNIT WIDTH AT 90 DEGREES.

MAY REQUIRE A LARGER CLEARANCE.

JURISDICTIONS MAY REQUIRE A LARGER DISTANCE.

MAY REQUIRE A LARGER DISTANCE.

4.50

[152]

MIN.

[22] .86

(TYP)

(TYP)

6.00

[11]

.44

[114]

FRONT

PLAN FOR UNITS

TYPICAL ANCHOR

DOOR

MIN.

5MIN.

30.00

[25]

[35]

(TYP)

1.37

1.00

MIN.

[762]

THE FOUNDATION'S SURFACE SHALL BE LEVEL WITHIN

± 0.0125 INCH IN 36 INCHES [0.318 MM IN 914.4 MM]

LEFT TO RIGHT, FRONT TO REAR, AND DIAGONALLY,

AS MEASURED BY A LASER LEVEL AT ANY POINT BENEATH

THE SWITCHGEAR ASSEMBLY.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 14 Effective: April 2006

3.8.2 Indoor Installations

Indoor vertical sections may be secured to the founda-tion using 0.5 in. (12.7 mm) anchor bolts. The four

0.625 in. (15.88 mm) holes in the base for these bolts are shown on the floor plan included with the drawings.

Figure 19 shows the floor plan for typical indoor MVS switchgear installations.

Figure 19. Floor Plan of a Typical Indoor MVS 27 kV or 38 kV Vertical Section, Non-Seismic or Seismic.

3.8.3 Outdoor Installations

Outdoor vertical sections are secured using clips and foundation bolts. Lead anchors and lag screws may be used in place of J-bolts if desired.

Figure 20 shows the floor plan for typical indoor MVS switchgear installations.

Figure 20. Floor Plan of a Typical Outdoor MVS 27 kV or 38 kV Vertical Section, Non-Seismic or Seismic.

MIN.

MIN.

[25]

6.00

MIN.

MIN.

30.00

UNITS

PLAN FOR INDOOR

TYPICAL ANCHOR

(TYP)

5.81

5.81

TYP.

MAY REQUIRE A LARGER DISTANCE.

MINIMUM CLEARANCES IN REAR. LOCAL JURISDICTIONS

JURISDICTIONS MAY REQUIRE A LARGER DISTANCE.

MINIMUM CLEARANCES IN FRONT IS THE WIDTH OF THE

MAY REQUIRE A LARGER CLEARANCE.

MINIMUM CLEARANCES ON SIDE. LOCAL JURISDICTIONS

DOOR SWING EQUALS UNIT WIDTH AT 90 DEGREES.

LOCATIONS FOR 0.50 INCH [13 MM] ANCHOR BOLTS.

WIDEST VERTICAL SECTION PLUS ONE INCH. LOCAL

[762]

[148]

[148]

[152] 1.00

1.28

(TYP)

2.12

(TYP)

[54]

[33]

FRONT

DOOR

THE FOUNDATION'S SURFACE SHALL BE LEVEL WITHIN

± 0.0125 INCH IN 36 INCHES [0.318 MM IN 914.4 MM]

LEFT TO RIGHT, FRONT TO REAR, AND DIAGONALLY,

AS MEASURED BY A LASER LEVEL AT ANY POINT BENEATH

THE SWITCHGEAR ASSEMBLY.

TYPICAL ANCHOR

PLAN FOR OUTDOOR

UNITS

30.00

MIN.

MIN.

MAY REQUIRE A LARGER DISTANCE.

MINIMUM CLEARANCES IN REAR. LOCAL JURISDICTIONS

JURISDICTIONS MAY REQUIRE A LARGER DISTANCE.

MINIMUM CLEARANCES IN FRONT IS THE WIDTH OF THE

MAY REQUIRE A LARGER CLEARANCE.

MINIMUM CLEARANCES ON SIDE. LOCAL JURISDICTIONS

DOOR SWING EQUALS UNIT WIDTH AT 90 DEGREES.

LOCATIONS FOR CUSTOMER'S TIE-DOWN CLIPS.

WIDEST VERTICAL SECTION PLUS ONE INCH. LOCAL

[762]

MIN.

[25]MIN.

[152] 3

1.28

(TYP)

(TYP)

[33]

4.50

(TYP)

[51]

(TYP)

(TYP)

[13]

(TYP)

(TYP)

.53

[114]

.53

2.00

6.00 1.00

1.28

[13] [33] 2.31 [59]

FRONT

DOOR

THE FOUNDATION'S SURFACE SHALL BE LEVEL WITHIN

± 0.0125 INCH IN 36 INCHES [0.318 MM IN 914.4 MM]

LEFT TO RIGHT, FRONT TO REAR, AND DIAGONALLY,

AS MEASURED BY A LASER LEVEL AT ANY POINT BENEATH

THE SWITCHGEAR ASSEMBLY.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 15

3.9 Connection of Space Heaters to Customers

Source Space heaters, when supplied, must be energized to prevent condensation. Heaters are supplied for 120- or 240-volt sources as shown on the drawings.

For switchgear assemblies with or without heater con-trol devices, heaters will be internally wired and brought to a terminal block. A wiring diagram will be furnished with the drawings showing connection points for power.

3.10 Superstructure Assembly

3.10.1 Receiving

Check to verify that all parts necessary for assembly have been received. The packing list will show all required items (bus, hardware, phase barriers, taping material, etc.) and will indicate in which shipping subas-sembly the various parts are located.

3.10.2 Installation of the Superstructure

Step 1: If a multiple vertical section assembly, join as per the instructions in Section 3.1. Secure the vertical sections to the foundation as per the instructions in Section 3.8.

Step 2: Remove the top sheet from the vertical section.

On indoor switchgear, this top sheet will later be re-installed on the superstructure using the same mounting hardware. Outdoor switchgear is shipped with the roof attached to the super-structure portions of the vertical sections.

The top sheet on the lower portion of each ver-tical section is used for shipping purposes only and may be discarded after removal.

Step 3: Remove the superstructure from the shipping pallet and then remove all covers. Shipment of more than one MVS vertical section will be tagged to identify superstructures with their corresponding switch units. Install the super-structure atop the vertical section(s) using the bolts, nuts, washers, and/or self-tapping screws as provided. Occasionally, the super-structure assembly will become slightly "sprung" in shipment so that it does not align exactly with the top of the switch enclosure. If this should occur, install the bolts or screws in all holes that align then use a pinwrench to pry adjacent holes into alignment.

Step 4: Remove the bolts securing the lifting eyes.

Remove the lifting eyes then replace mounting bolts just removed.

3.10.3 Bus Assembly

All bus sections have been assembled at the factory and checked for clearance prior to shipment.

Step 1: Units without a horizontal main bus require installation of one piece of bus section per phase from the upper switch terminal pad to the incoming line termination. Each phase bus is attached in two places:

• to the upper switch terminal pad; and

• to the bus support insulator mounted in the superstructure.

Use the bolts provided to secure the bus sec-tions.

Step 2: Units with a main bus also require horizontal bus sections bolted to the bus support insula-tors. Phase bus risers are then bolted from the switch terminal pad to the main horizontal bus.

Lineups shipped in more than one section will be supplied with horizontal bus lengths corre-sponding to widths of shipping sections.

After installation, join the horizontal bus sec-tions using the splice plates provided.

Step 3: Tighten all bolted bus connections to the torque values given in Section 9.

Step 4: Any bus requiring field taping will be identified by a red taping tag. Taping material is pro-vided. The taping procedures, described in Section 3.7, should be followed.

3.10.4 Replacing Covers

Step 1: Install the roof panels and switchgear covers using hardware provided.

Step 2: For outdoor units, install the roof caps accord-ing to the procedures detailed in Section 3.2.

3.11 Switch Inspection Before Startup

WARNING

FAILURE TO ASSURE THAT NO TOOLS OR OTHER

OBJECTS ARE ACCIDENTALLY LEFT INSIDE EACH

VERTICAL SECTION MAY RESULT IN EQUIPMENT

DAMAGE, BODILY INJURY, OR DEATH.

BEFORE REPLACING COVERS, THOROUGHLY INSPECT

BUS WORK AND PHASE BARRIERS, THEN PERFORM

FIELD DIELECTRIC TESTS TO ASSURE THAT NO

TOOLS OR OTHER OBJECTS ARE ACCIDENTALLY

LEFT INSIDE EACH VERTICAL SECTION AND THE

DIELECTRIC INTEGRITY OF THE SWITCHGEAR ASSEM-

BLY IS INTACT.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 16 Effective: April 2006 Step 1: Check bolted bus connections for proper tight-ness, referring to Section 9 for recommended torque values.

Step 2: If non-disconnect mounted fuses are supplied, check the plastic knobs that hold the fuses in place. They should be hand tight.

Step 3: If disconnect fuses are supplied, check to see that they are completely latched closed.

Step 4: For units fitted with expulsion-type, boric acid fuses, check the discharge filters on the lower end of the fuses for tightness. They must be securely hand tightened.

Step 5: Check to see the space heaters, if supplied, are energized.

Step 6: Wipe away any dust or dirt that may have accu-mulated in compartment(s), paying particular attention to insulators and insulating material.

If the bus is insulated, see Section 5.4 for cleaning procedures.

Step 7: A final thorough inspection should be made to insure that no tools or other objects are acci-dentally left inside the enclosure.

Section 4: Operation

4.1 Mechanical Safety Interlocks

The MVS switch is equipped with switch interlocks and door inter-locks, as well as provisions for padlocking in either the “Open” or “Closed” position.

4.1.1 Switch Interlock

The switch interlock prevents inadvertent closure of the switch if the enclosure door is open. When the door is closed, the pointed latch lug welded to the inside of the door causes the safety latch to move out of the blocking position (see Figure 21).

Figure 21. Door/Switch Mechanism and Shaft Interlock Locations.

4.1.2 Door Interlock

The door interlock prevents the door of the enclosure from being opened when the switch is “Closed”. When the switch is “Closed”, a cam welded to the operating shaft engages a bracket welded to the inside of the switch door, preventing the door from being opened (see Figure 21).

WARNING

EACH SWITCH IS PROPERLY ADJUSTED AT THE FAC-

TORY BEFORE SHIPMENT. HOWEVER, VIBRATION

AND MECHANICAL STRESSES IMPOSED BY TRANSIT

AND INSTALLATION CAN ADVERSELY AFFECT

SWITCH ADJUSTMENT. THEREFORE, A FINAL

INSPECTION IS ESSENTIAL BEFORE ENERGIZING.

IF THIS INSPECTION REVEALS ANY DEFECTS IN

ADJUSTMENT, THEY SHOULD BE CORRECTED

ACCORDING TO ALIGNMENT PROCEDURES IN SEC-

TION 5.2.

WARNING

DEFEATING OR DISENGAGING SAFETY INTERLOCKS

ON AN MVS SWITCH THAT IS CONNECTED TO A

POWER SOURCE MAY RESULT IN PROPERTY DAM-

AGE, BODILY INJURY OR DEATH.

DO NOT DEFEAT OR DISENGAGE ANY SAFETY INTER-

LOCKS.

Mechanism Cover

Door/Switch Shaft Interlock

Door/Switch Mechanism Interlock

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 17

4.1.3 Key Interlocking

Key interlocks are supplied when specified. Certain MVS switchgear configurations require key interlocks and they are therefore included.

Standard schemes are available for locking the switch in the “Open” or the “Closed” position, as well as locking the main door closed. Numerous other schemes are available for special requirements that can coordinate with upstream or downstream devices supplied by Eaton Electrical, Inc. or other equipment.

4.1.4 Switch Operation

The quick-make mechanism provides power to over-come blowout forces that occur if the switch is “Closed” into a fault. However, these forces are not transmitted to the operating handle since it is not rigidly connected to the blades. Therefore, the switch can be safely closed under short circuit conditions within its fault-close rating.

Load interruption is accomplished by a flicker blade and engaging contact fingers located inside a DE-ION arc chute. On opening the switch, the main blades open first and all current is shunted through the spring loaded flicker blades. Further travel of the main blades causes the flicker blades to snap out of their contact fingers where associated arcing takes place within the arc chutes. See Figure 22 for the sequence of operation.

Figure 22. Main and Flicker Blade Operation.

4.2 Fuse Replacement

Step 1: All upstream devices that could energize the fuse should be opened, padlocked, and tagged so that inadvertent closure cannot create a haz-ard.

Step 2: The MVS switch should be in the “Open” posi-tion. This is accomplished by rotating the oper-ating handle downward.

Step 3: Before opening the door, look through a view-ing window to visually verify that all blades are disengaged from their break jaws.

Step 4: After opening the door, an appropriate medium voltage-sensing device should be used to deter-mine if voltage is present.

Step 5: If no voltage is present, a suitable grounding device should be attached to the fuse terminals to discharge any static charge and assure that the fuse terminals remain at ground potential.

Step 6: The fuses are removed by loosening the plastic hand knobs and removing the locking bars. The fuses are then free to be removed. When the fuses are re-installed, the hand knobs should be retightened hand tight.

Left Pole: Main Blade and Flicker Blade Closed.

Center Pole: Main Blade Open, Flicker Blade Closed.

Right Pole: Main Blade and Flicker Blade Open.

WARNING

WHEN ACCESSING FUSES, FAILURE TO ASSURE

THAT THE FUSES ARE DE-ENERGIZED MAY RESULT IN

EQUIPMENT DAMAGE, BODILY INJURY, OR DEATH.

MAKE SURE THAT ALL POWER SOURCES ARE DE-

ENERGIZED BEFORE ATTEMPTING TO ACCESS THE

FUSES.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 18 Effective: April 2006 Section 5: Maintenance

5.1 Inspection Schedule

The MVS switch should be inspected once a year or after its rated current interruptions, as specified in industry standard ANSI C37.22, whichever occurs first.

After the switch has been closed against a fault current, it should be inspected at first opportunity.

5.2 Inspection Procedure

5.2.1 Electrical Parts and Insulation Check and Cleaning

De-energize the primary circuits before removing any enclosure parts. Before cleaning, take “Megger” read-ings between live parts and to ground. Inspect the switch for signs of overheating or weakened insulation.

Remove dust from barriers, live parts, insulators, drive rod links, and enclosure surfaces. If necessary, wipe clean with isopropyl alcohol or distilled water, then wipe dry.

After the barriers, live parts, insulators, and drive rod links have been dusted and wiped clean, take “Megger” readings again between the live parts and between phases. Keep a record of these reading for future refer-ence in determining when trends occur that would indi-cate a lowering of the insulation resistance.

Periodic high potential tests are not required and are rec-ommended only after repair of high voltage live parts or insulation, or when the trend of “Megger” readings indi-cates it to be advisable. This field test should be made before the main cables are connected and should not exceed the values in the following table.

Table 3. Field Dielectric Test Values.

When finished cleaning and checking the switch, “Close” and “Open” the de-energized switch at least three (3) times to check the performance of the operat-ing mechanism.

5.3 Alignment Procedures

WARNING

FAILURE TO COMPLETELY DISCONNECT THE SWITCH

FROM ALL POWER SOURCES PRIOR TO INSPECTION

OR MAINTENANCE MAY RESULT IN SEVERE INJURY

OR DEATH.

THE SWITCH MUST BE COMPLETELY DISCONNECTED

FROM ALL POWER SOURCES BEFORE PERFORMING

ANY INSPECTION OR MAINTENANCE.

WARNING

NORYL INSULATED EQUIPMENT: ELECTRICAL JOINT

COMPOUNDS MUST NOT BE USED ON CONNECTIONS

OR TERMINATIONS TO OR FROM THIS EQUIPMENT.

DO NOT USE SOLVENTS, OILS, OR GREASES ON OR

NEAR THIS EQUIPMENT. WATER AND ISOPROPYL

ARE THE ONLY APPROVED CLEANERS FOR THIS

EQUIPMENT.

CAUTION

SOPROPYL ALCOHOL IS FLAMMABLE. PROVIDE ADE-

QUATE VENTILATION AND KEEP AWAY FROM

FLAMES AND OTHER IGNITION SOURCES.

CONSULT YOUR SAFETY DEPARTMENT BEFORE

USING.

kV CLASS TEST VOLTAGE, 60Hz AC, APPLIED

FOR ONE (1) MINUTE

4.76 14.25

15 27

27 45

38 60

WARNING

FAILURE TO COMPLETELY DISCONNECT THE SWITCH

FROM ALL POWER SOURCES PRIOR TO INSPECTION

OR MAINTENANCE MAY RESULT IN SEVERE INJURY

OR DEATH.

THE SWITCH MUST BE COMPLETELY DISCONNECTED

FROM ALL POWER SOURCES BEFORE PERFORMING

ANY INSPECTION OR MAINTENANCE.

CAUTION

LOW CLOSING OR SLOW OPENING THE SWITCH

AGAINST THE SPRING MAY RESULT IN BODILY

INJURY IF A PERSON IS NOT CAREFUL TO HOLD THE

OPERATING HANDLE FIRMLY.

BE SURE TO HOLD HE HANDLE FIRMLY WHILE PER-

FORMING SLOW CLOSING OR SLOW OPENING OPERA-

TIONS.

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 19

5.3.1 Override of the Switch Interlock Safety LatchTo

operate the switch with the door open, the safety latch (see Figure 23) must be disengaged. To close the switch, insert the handle into the handle casting and push upward, at the same time push the latch on the left side of the safety barrier downward until the handle casting clears the interlocking pin. Reverse this proce-dure to open the switch.

Figure 23. Defeating the Door/Mechanism Interlock.

5.3.2 Closed-Open-Stop Adjustment

Step 1: Remove the switch mechanism cover (see Fig-ure 23) by removing the three bolts in the side sheet flange. Viewing switch mechanism from the top, the bottom stop bolt and nut adjusts the closed position (see Figure 25). In the closed position, the shaft rod ends should be slightly over toggle. This can be easily checked by laying a straight edge on top of the drive rod so that its end extends over the shaft (see Fig-ure 24). If a 0.0625 to 0.125 in. (1.59 to

3.18 mm) gap appears between straight edge and drive rod, the adjustment is correct.

Figure 24. Over Toggle Check.

Figure 25. Closed-Open-Stop Adjustment Bolts.

Note: There are two blade and break jaw configurations used on the “MVS” (previously the WLI) switch design. The original design used a flat break jaw with a “hook” cutout on the bottom and each blade had two indentations (“bullets”) that bore onto the break jaw surfaces. The later design, initiated in the year 2000, used a break jaw that has a ridge on each side and each blade has flat contact surfaces. This instruction book will address only the later design.

Straight Edge

Drive Rod

.06 - 12

Bolts

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Page 20 Effective: April 2006 Step 2: Check to see that the blades are closing fully.

To do this, measure the distance from the end of the break jaw to the front edge of the blade.

This dimension should be 0.10 to 0.30 in.

(2.54 to 7.62 mm). Should adjustment be required, loosen the bolt holding the drive rod to the shaft and adjust the blade travel. Re-tighten the bolt to 25 ft-lbs (33.90 N-m) (see Figure 27).

Figure 26. Break Jaw and Blade Clearances.

In the “Open” position, the clearance between the edge of the main blade and the break jaw should be as listed in Table 4 (see Figure 27).

The top stop bolt adjusts this dimension.

Table 4. Main Blade to Break Jaw Clearances.

Figure 27. Open Gap Distance.

Step 3: If the switch is equipped with key interlocking, care must be taken when replacing the switch mechanism cover to insure that it is properly repositioned. Elongated holes in the MVS side sheet allow for vertical adjustment. The key interlock bolt must clear the “Open-Closed” indicating cam casting when retracted.

5.3.3 Main Blade Alignment

For the following procedure, refer to Figure 28.

Figure 28. Main Blade and Flicker Blade Alignment.

OPEN GAP DIMENSION

in. (mm) kV CLASS

6.625 ± 0.125 (168.28 ± 3.18) 4.76

6.625 ± 0.125 (168.28 ± 3.18) 15

11.00 ± 0.125 (279.40 ± 3.18) 27 or 38

Open Gap Distance

Switchgear: 4.76 kV, 15.0 kV, 27.0 kV, and 38.0 kV

Instructional Booklet Effective: April 2006 Page 21 Step 1: Loosen the four (4) hinge bolts and the two (2) break jaw bolts. Insert the removable handle in the maintenance hub on the shaft and “Close” the switch.

Note: For safety purposes, the switch will not fully “Close” and will revert to the “Open” position if pressure on the handle is released.

Step 2: Hold the switch in the “Closed” position with the handle and tighten the bolts on both the hinge and jaw per the torque specifications given in Section 9.

5.3.4 Arc Chute Alignment

For the following procedure, refer to Figure 28.

Step 1: Loosen the two arc chute mounting bolts.

Adjust the arc chute so that its opening is paral-lel to the main blade then lightly tighten the mounting bolts.

Step 2: Using the blade alignment hub, slowly close the switch and check that the flicker blade is in line with the arc chute opening. If necessary, move the arc chute left or right until it lines up with the flicker blade.

Step 3: Tighten the arc chute mounting bolts and recheck the alignment.

5.3.5 Vertical Position of Break Jaw

Step 1: Close the switch. Check that the upper spac-ers of the main blades are 0.1875 ± 0.0625

in. (4.76 ± 1.59 mm) above the tops of the break jaws. (See Fig. 22)

Step 2: If they are not, loosen the bolts holding the break jaw and adjust as necessary. When the setting is correct, tighten bolts to proper torque value (see Section 9).

5.3.6 Break Jaw Bolt and Hinge Contact Bolt Tightness

The disk springs on the main blade assembly must pro-vide the necessary contact pressure between the main blades and stationary mating parts when the switch is “Closed”. At the break jaw end, the elastic stop nut must be removed, then a sensitive torque wrench used to set the proper contact pressure as given in Table 5.

Table 5. Necessary Contact Pressure

For the hinge end, there are two configurations:

• If there is only an elastic stop nut installed, tighten it to 25 ft-lb (33.90 N-m), and then back off the nut one full turn.

• If there is an elastic stop nut that jambs a standard hex nut, remove the elastic stop nut, tighten the stan-dard hex nut to 20 ft-lb (27.12 N-m), then back off one full turn. Reinstall the locking nut and jamb it against the standard hex nut, being careful not to turn either the bolt or the standard nut.

Note: Standard ohm readings between the top terminal pad and the bottom terminal pad on each pole are not to exceed 60 micro ohms.

5.4 Replacement Procedures

5.4.1 Main Blade Subassembly and Break Jaw

Replacement The switch should be in the closed position. Disconnect the drive rod link from the main blade assembly by removing the clevis pins (see Figure 27).

5.4.1.1 Method A

For the following procedure,…