Section_C-2_Specification_Switchboards.pdf

Department of Homeland Security (DHS)

United States Coast Guard (USCG)

270’ MEDIUM ENDURANCE CUTTER

(WMEC) SERVICE LIFE EXTENSION (SLEP)

ELECTRICAL POWER GENERATION

70Z02319R

Attachment C-2

Technical Specification

SWITCHBOARDS

May 10, 2019

TECHNICAL SPECIFICATION: 270’ WMEC SLEP SWITCHBOARDS

Table of Contents

1.0 REQUIREMENTS APPLICABILITY

1.1 Requirements Applicability

1.2 General Requirements

2.0 SWITCHBOARDS - GENERAL REQUIREMENTS

2.1 Dimensional Constraints

2.2 Physical Construction

2.3 Maintenance Accessibility

2.4 Switchboard Instruments

2.5 Digital Displays

2.6 Switches

2.7 Indicator Lights

2.8 Switchboard Wiring

2.9 Switchboard Lighting

2.10 Bus Work

2.11 Real Load Sensing Devices

2.12 Voltage Sensing Devices

2.13 Circuit Protection

2.14 Spare Circuit Breakers

2.15 Schematic Wiring Diagram

3.0 SHIP SERVICE SWITCHBOARD

3.1 Special Performance Requirements

3.2 Overall Dimensions

3.3 Arrangement

3.4 Switchboard Synchronization Section

3.5 Switchboard Generator Sections

3.6 Switchboard Distribution Section

3.7 Additional Switchboard Equipment

4.0 EMERGENCY SWITCHBOARD

4.1 Special Performance Requirements

4.2 Overall Dimensions

4.3 Switchboard Generator Section

4.4 Switchboard Distribution Section

4.5 Additional Switchboard Equipment

1.0 REQUIREMENTS APPLICABILITY

1.1 Requirements Applicability

1.1.1 The requirements listed herein are supplemental to the Electrical Power Generation SOW.

If a conflict of requirements is found, the SOW takes precedence.

1.1.2 This Spec is inclusive of all equipment contained within the switchboards; however, the replacement of the entire switchboard is neither required nor recommended. The extent of the switchboard modifications is dependent on the contractor’s proposed design.

1.1.3 There currently exists one ship service switchboard (dual bus, with controls for two generators) and one emergency switchboard for the control, operation, and protection of the ship service generators and the emergency generator, respectively.

1.1.4 The existing switchboards shall be modified as required for the integration of new generator sets, replacement of worn or obsolete components and extension of service life.

1.1.5 Items identified in this Spec that will not be modified or affected by the Contractor’s proposed design are not applicable nor enforceable.

1.1.6 All proposed shipboard modifications shall meet the requirements specified herein.

1.2 General Requirements

1.2.1 The equipment covered in this section shall be constructed and installed in accordance with

IEEE Standard 45, "Recommended Practice for Electrical Installations on Shipboard", unless otherwise specified.

2.0 SWITCHBOARDS - GENERAL REQUIREMENTS

2.1 Dimensional Constraints

2.1.1 The ship service switchboard shall remain located in the ECC as shown on the plans. The emergency switchboard shall remain located in the Steering Gear Room as shown on the plans.

2.1.2 The overall dimensions of the revised switchboards shall not exceed the physical envelopes of the existing switchboards.

2.1.3 The ship service switchboard components must fit through a 26" x 60" opening. The emergency switchboard components must fit through a 36" x 36" opening.

2.2 Physical Construction

2.2.1 The switchboards shall be free-standing, dead front, metal-enclosed, and of rugged marine-type construction framed with angle iron and channels. Welded gusset plates shall be provided in all corners.

2.2.2 The ship service switchboard and the emergency switchboard shall be assembled from a series of individual free-standing units bolted together. All switchboards shall be mounted on steel channels and firmly secured.

2.2.3 Each switchboard shall be capable of performing its intended function satisfactorily in the environment in which it is installed and during the operational conditions described in the

SOW. In addition, each switchboard shall be designed for continuous operation without mechanical or electrical damage in any compartment ambient temperature between the limits of 0 degrees C and 50 degrees C.

2.2.4 Switchboards shall be accessible from the front and rear.

2.2.5 Grab rods shall be mounted on the front and rear of switchboards so that operator and maintenance personnel will have a means of support. The rods shall be of smooth hardwood, 1-1/4-inch diameter, with supporting brackets and attached in such a manner that panels can be removed or opened without removal of the rods. These rods shall be located so that they will not interfere with operation of the equipment and shall not extend more than 4 inches from the front of the panel.

2.2.6 Drip shields shall be provided which shall extend at least 4 inches over front and rear of each switchboard.

2.2.7 The switchboard cables shall enter the switchboard from the bottom. Cable supports shall be provided where necessary.

2.2.8 Instruments and control switches shall be mounted on hinged metal panels. These panels shall be provided with door stops and holding devices to secure them in the open position.

2.2.9 Switchboard and components will be exposed to regular humidity and airflow that has been shown to accelerate corrosion. Switchboard and components shall include preservation for a marine environment.

2.2.10 Equipment shall be designed with consideration given to the placement of parts, such that no part shall be exposed to a higher temperature than the maximum rated part temperature in the surrounding ambient air.

2.3 Maintenance Accessibility

2.3.1 All parts and subassemblies which may require servicing, repair or replacement during the life of the equipment shall be readily accessible.

2.4 Switchboard Instruments

2.4.1 Switchboard instruments shall be designed, constructed, and installed into the switchboard as follows:

2.4.1.1 Instruments shall be designed and constructed to exclude the entry of dust and moisture and shall operate over a period of two years without loss of accuracy.

2.4.1.2 Instrumentation shall be clearly legible. Analog meters shall have a white background with black markings and black numbers. Red markings and red numbers shall be used for values beyond the equipment’s rated values.

2.5 Digital Displays

2.5.1 Digital displays shall be clearly legible and shall show numbers at a vertical size equal to or greater than .5 inches. The display’s color contrast shall not impede viewers with colorblindness. The display shall provide a method to alert the viewer that values are out of normal limits, such as a change in color or flashing.

2.6 Switches

2.6.1 Switches installed for instrument transfer or control functions shall be clearly marked with escutcheon plates to indicate their function and position.

2.7 Indicator Lights

2.7.1 Indicator lights shall be flush mounted and shall be designed to incorporate two incandescent or LED lamps under the lens, except ground detector lights which shall be single lamp type. For low voltage indicator lights, an integral transformer, rectifier, or power supply shall be installed, as required. Bulb size and base shall be standard throughout the switchboard. All lights shall be clearly marked to indicate function.

2.8 Switchboard Wiring

2.8.1 Switchboard wiring shall be as follows:

2.8.1.1 Wiring shall be of the stranded type and shall be neatly bundled in groups.

Wires shall be routed through a wiring management system or tightly secured to form a harness.

2.8.1.2 In places where the wires transit across moving sections (such as doors) and are not part of a wiring management system, the wires shall be securely grouped into a harness and be covered with an anti-chafing material.

2.8.1.3 Where these wires must be installed through the steel structure or sheet metal partitions, bushings shall be inserted to avoid chafing of the wire insulation.

2.8.1.4 Where instrument and control wiring passes between frames which may be separated to segregate the switchboard into shipping sections, terminal blocks shall be provided to permit disconnecting of wiring. Similarly, where the control, instrument, or alarm wiring leaves the switchboard, terminal blocks shall be provided for connection of the cutter's cables. Terminal blocks shall be equipped with identification strips. Wiring shall be marked near the terminal point.

2.9 Switchboard Lighting

2.9.1 The front surface of the switchboards shall be fully lighted. Lighting shall be by self-charging emergency type fixtures. The fixtures shall each provide at least 2400 lumens of light on AC power. The fixtures shall each provide a minimum of 1200 lumens for a minimum of 60 minutes after loss of power.

2.10 Bus Work

2.10.1 All bus work shall be copper. All bus bars and connections shall be provided with silver surfaced contacts as specified in IEEE 45. All bus work shall be braced to withstand the maximum short circuit current available as determined by the required fault current analysis.

2.11 Real Load Sensing Devices

2.11.1 The ship service and emergency switchboards shall be provided with real load sensing devices which will provide signals to the MPCMS console in the ECC. The console systems shall provide high load alarms when any generator reaches 90% of its rated output power or when two ship service generators operating in parallel are loaded to 75% of their combined rated output power.

2.12 Voltage Sensing Devices

2.12.1 All switchboards shall be provided with voltage sensing devices which provide a switched

(on/off) signal to the MPCMS console in the ECC whenever any bus voltage drops below the lower limit of Type I power defined in MIL-STD-1399.

2.13 Circuit Protection

2.13.1 All switchboards shall contain circuit protection for the distribution feeders as dictated by the design of the 60-Hz distribution system and the guidance of the plans.

2.14 Spare Circuit Breakers

2.14.1 A minimum of one spare circuit breaker of each frame size for each five active circuit breakers or fraction thereof shall be installed in the distribution section of each switchboard.

One of these spare circuit breakers of each frame size in each switchboard shall be supplied with a trip element that is of a size equal to its frame rating. All other circuit breakers of each frame size in each switchboard shall be supplied with trip elements sized the same as those most frequently used throughout the switchboard distribution section.

2.15 Schematic Wiring Diagram

2.15.1 A schematic wiring diagram shall be included in an oil/moisture resistant envelope or enclosure inside each switchboard. The drawing shall be size 24” x 36” or smaller. If the printed size of the diagram is smaller than the original drawing, the printed text shall be no smaller than 1/8” tall and line weights shall be scaled.

3.0 SHIP SERVICE SWITCHBOARD

3.1 Special Performance Requirements

3.1.1 The ship service switchboard shall contain two 450 volt buses, one for each ship service generator, linked together by a bus tie circuit breaker. Since the ship service electric plant is designed for one ship service generator to meet the electrical load requirements when the cutter is performing any conceivable mission, the bus tie circuit breaker between the two ship service buses shall normally be closed. Thus, the ship service electric plant shall appear as if it were a single bus system.

3.1.2 The operator at the ship service switchboard shall be able to manually or automatically synchronize, then manually parallel, any two generators. In addition, the operator shall also have the capability to manually synchronize and parallel the ship service bus with shore power. Generator, bus tie, and shore tie circuit breakers shall be interlocked so as to prohibit being closed onto an energized bus without being synchronized first. The circuitry for the automatic and manual synchronization systems shall be independent to the extent that a failure of one synchronization system will not render the other synchronization system inoperable.

a) The ship service switchboard shall contain a Parallel Selector Switch for selecting non-parallel, or paralleling of generator #1, generator #2, emergency generator, or shore power with the ship service bus. The non-parallel position of the selector switch shall de-energize the synchronizing equipment. The parallel selector switch shall be used by the switchboard operator to choose which electrical source will be placed in parallel with an existing on-line ship service generator. The selector switch will activate the synchronizing equipment, arm the breakers for operation, and perform any other operation necessary for paralleling.

b) A separate Parallel Mode Switch shall be provided to determine whether synchronizing will be automatic or manual.

3.1.3 The ship service switchboard shall contain a standby selector switch so that the operator can choose which generator to have as a backup. The standby selector switch shall permit ship service generator #1, #2, or the emergency generator to be selected as standby.

a) If one of the ship service generators is selected as standby, a failure of the on line generator shall initiate automatic starting of the standby ship service generator.

i. If the ship service switchboard bus tie is open, a ship service generator selected for standby shall not automatically start.

ii. If for some reason the standby ship service generator set does not start, the automatic starting of the emergency generator set shall then be initiated.

An adjustable time delay, ranging from ten to thirty seconds, shall be used to determine when initiation of the starting of the emergency generator shall take place.

b) If the emergency generator is selected as standby, failure of the on-line ship service generator shall initiate the immediate (no time delay) automatic starting of the emergency generator.

3.1.4 The ship service generator circuit breakers shall provide short circuit current, overload, and reverse power protection for the ship service generators. An undervoltage trip mechanism shall be supplied with the circuit breaker with an adjustable range of 60% to 100% of system nominal voltage. The undervoltage trip mechanism shall also prevent the circuit breaker from closing if the generator is not generating. The operation of the undervoltage mechanism shall be instantaneous when preventing closure of the breaker, but is to be delayed for discrimination purposes when tripping the breaker. In addition, the ship service generator circuit breakers shall be equipped with shunt-trip mechanisms to be controlled by shutdown signals (normal, overspeed or other) from the generator controls. An overspeed switch on the generator sets shall activate when prime mover speed causes generator frequency to exceed the limits designated by Type I power as defined in MIL-STD-1399.

3.1.5 The bus tie circuit breaker between the ship service bus and the emergency bus shall provide short circuit current protection for the emergency bus and the bus tie feeder and shall coordinate with the ship service generator circuit breakers to trip first in the case of a downstream fault (on the bus tie feeder or emergency bus).

a) A shunt trip mechanism shall be supplied with the circuit breaker. This mechanism shall open the breaker when the emergency generator circuit breaker is switched to the position where the emergency generator is feeding the emergency bus.

b) In the event that backfeeding power from the emergency switchboard to the ship service switchboard is desired, the closing of the backfeed switch on the ship service switchboard shall defeat the shunt trip mechanism on the bus tie breaker, allowing the bus tie breaker to be closed to complete the backfeed of the ship service bus by the emergency generator.

3.1.6 The bus tie circuit breaker between the two sections of the ship service bus shall provide short circuit current protection for each section of the bus and shall coordinate with the ship service generator circuit breakers to trip first in the case of a fault on the opposite side of the bus from the active generator.

3.1.7 The shore tie circuit breakers shall supply short circuit current and overload protection for the ship service bus. These breakers shall also trip upon the loss of a phase on the shore power supply. The shore tie circuit breakers shall be interlocked so that only one shore tie circuit breaker can be closed at any one time.

3.2 Overall Dimensions

3.2.1 The overall dimensions of the modified ship service switchboard shall not exceed the physical envelope of the existing ship service switchboard. The modified ship service switchboard shall be in the same location as the existing ship service switchboard, in the

ECC, as shown in USCG Drawings 905-WMEC-324-002 and 905-WMEC-324-003 for B-

Class Cutters and 901-WMEC-324-002 for A-Class Cutters.

3.3 Arrangement

3.3.1 The arrangement of the ship service switchboard shall ensure that the operator can perform synchronization procedures for paralleling generators from the center of the switchboard without having to move from side to side.

3.4 Switchboard Synchronization Section

3.4.1 The synchronization section of the ship service switchboard shall contain as a minimum the following equipment (quantity 1 each unless otherwise indicated)

a) AC Voltmeter and Selector Switch – or other means to monitor voltage on each phase of the incoming source, scale appropriate for 450 V.

b) Frequency Meter and Selector Switch – or other means to monitor frequency of the incoming source, scale appropriate for 60 Hz.

c) Parallel Selector Switch – or other means of selecting non-parallel, or paralleling of generator #1, generator #2, emergency generator, or shore power with the ship service bus (see Section 3.1.2(a)).

d) Parallel Mode Switch – or other means of selecting automatic or manual synchronization (see Section 3.1.2(b)).

e) Synchroscope – or other means to enable manual synchronization of a generator with an active bus.

f) Standby Generator Selector Switch – for selecting ship service generator #1, #2, or the emergency generator to be on standby (see Section 3.1.3).

g) Backfeed Control Switch – or other means for enabling backfeed operation from the emergency switchboard to the ship service switchboard (see Sections 3.1.5(b) and

4.1.2(b)).

h) Shore Tie Circuit Breakers (2 each) - to be located in the bottom of the synchronization section. The forward shore tie breaker shall be connected to the starboard ship service bus (1S). The aft shore tie breaker shall be connected to the port ship service bus (2S).

3.5 Switchboard Generator Sections

3.5.1 There shall be two generator sections, one for each ship service generator. Each of these generator sections shall contain, as a minimum, the following equipment (quantity 1 each unless otherwise indicated):

a) Generator Circuit Breaker, Control Switch, and Indicator Light – to control generator circuit breaker and indicate its position.

b) AC Voltmeter and Selector Switch – or other means to monitor voltage on each phase of the generator and bus, scale appropriate for 450 V.

c) Ammeter and Selector Switch – or other means to monitor each line of generator current.

d) Frequency Meter – or other means to monitor frequency of the generator, scale appropriate for 60 Hz.

e) Polyphase Wattmeter – or other means to monitor total output power of generator.

f) Power Factor Meter – or other means to monitor the power factor of the generator, with 0.5 lagging to 0.5 leading indication shown on a 180-degree scale (centered at unity power factor), or digital equivalent.

g) Reverse Power Relay – to trip generator breaker in case of reverse power flow.

h) Governor Control Device – for controlling speed and output frequency of genset.

i) Voltage Regulator, including Auto-Manual Switch and Voltage Adjusting Device

(knob or switches) – for automatic or manual control of generator output voltage.

j) Automatic Synchronizing Device – for automatic synchronization of generator with an active bus.

k) Generator Strip Heater Contactor, Control Switch, and Indicator Light – to control generator strip heater. In addition, heater shall be interlocked to automatically de-energize when the generator is started.

l) Load Sensor and Contacts – or other means to provide the signal described in

Section 2.9 to CGMCS.

m) Voltage Sensing Device – or other means to provide the signal described in Section

2.10 to CGMCS.

n) Temperature Meter(s) and Selector Switch – or other means of monitoring temperatures of the generator windings.

3.6 Switchboard Distribution Section

3.6.1 The distribution section of the switchboard shall contain circuit breakers for circuit protection of the 450 volt distribution system as shown on the plans and as required by the final design of the ship service distribution system.

3.7 Additional Switchboard Equipment

3.7.1 The following equipment, along with any other equipment required by the switchboard design but not listed previously, shall be installed in the switchboard (quantity 1 each unless otherwise indicated):

a) Bus Tie Circuit Breaker - tying ship service bus #1 to ship service bus #2.

b) Bus Tie Circuit Breaker - tying ship service bus to emergency bus.

c) Potential, current, and control transformers as required.

d) Fuse panel for fusing the potential, current, and control transformers and any other required circuits.

e) Ground Detection Test Switch and Indicator Lights (2 sets) or Line Insulation

Monitors (2 each) or other means to monitor the isolation from ground of each switchboard bus.

f) Shore Power Indicator Lights (4 each) – or other means to indicate when shore power available at each of the 4 shore power receptacles (2 forward, 2 aft).

g) Phase Rotation Indicator and Selector Switch – or other means for checking shore tie phase rotation at each of the 4 shore power receptacles.

4.0 EMERGENCY SWITCHBOARD

4.1 Special Performance Requirements

4.1.1 The emergency generator circuit breaker shall provide short circuit current, overload, and reverse power protection for the emergency generator. An undervoltage trip mechanism shall be supplied with the circuit breaker with an adjustable range of 60% to 100% of system nominal voltage. In addition, the emergency generator circuit breaker shall be equipped with a shunt-trip mechanism to be controlled by shutdown signals (normal, overspeed or other) from the generator controls. An overspeed switch on the generator set shall activate when prime mover speed causes generator frequency to exceed the limits designated by Type I power as defined in MIL-STD-1399.

4.1.2 The bus tie circuit breaker shall provide short circuit current and overload protection for the ship service bus and bus tie feeder and shall coordinate with the emergency generator circuit breaker to trip first in the case of a downstream fault (on the bus tie feeder or ship service bus).

a) The bus tie circuit breaker shall be interlocked with the emergency generator circuit breaker so that they cannot both be closed simultaneously (to isolate the ship service bus during emergency operation).

b) In the event that backfeeding power from the emergency switchboard to the ship service switchboard is desired, the closing of the backfeed switch on the ship service switchboard shall override the interlock on the bus tie breaker, allowing the bus tie breaker to be closed to complete the backfeed of the ship service bus by the emergency generator.

4.1.3 The emergency generator circuit breaker shall allow the operator at the emergency switchboard to manually or automatically synchronize, then manually parallel the emergency generator with the emergency bus. The emergency generator circuit breaker and the bus tie circuit breaker shall be interlocked with the synchronization system so as to prohibit being closed onto an energized bus without being synchronized first. The circuitry for the automatic and manual synchronization systems shall be independent to the extent that a failure of one synchronization system will not render the other synchronization system inoperable or unusable.

a) The emergency switchboard shall contain a Parallel Selector Switch for selecting non-parallel, or paralleling of the emergency generator with the emergency bus. The non-parallel position of the selector switch shall de-energize the synchronizing equipment. The selector switch will activate the synchronizing equipment, arm the breakers for operation, and perform any other operation necessary for paralleling.

b) A separate Parallel Mode Switch shall be provided to determine whether synchronizing will be automatic or manual.

4.2 Overall Dimensions

4.2.1 The overall dimensions of the modified emergency switchboard shall not exceed the physical envelope of the existing emergency switchboard. The modified emergency switchboard shall be in the same location as the existing emergency switchboard, in the

Steering Gear Room, as shown in USCG Drawings 905-WMEC-324-002 and 905-WMEC-

324-003 for B-Class Cutters or 901-WMEC-324-005 for A-Class Cutters.

4.3 Switchboard Generator Section

4.3.1 The generator section of the emergency switchboard shall contain as a minimum the following equipment (quantity 1 each unless otherwise indicated):

a) Generator Circuit Breaker, Control Switch, and Indicator Light – to control generator circuit breaker and indicate its position.

b) AC Voltmeter and Selector Switch – or other means to monitor voltage on each phase of the generator and bus, scale appropriate for 450 V.

c) Ammeter and Selector Switch – or other means to monitor each line of generator current.

d) Frequency Meter and Selector Switch – or other means to monitor frequency of the generator and bus, scale appropriate for 60 Hz.

e) Polyphase Wattmeter – or other means to monitor total output power of generator.

f) Power Factor Meter – or other means to monitor the power factor of the generator, with 0.5 lagging to 0.5 leading indication shown on a 180-degree scale (centered at unity power factor), or digital equivalent.

g) Reverse Power Relay – to trip generator breaker in case of reverse power flow.

h) Governor Control Device – for controlling speed and output frequency of genset.

i) Voltage Regulator, including Auto-Manual Switch and Voltage Adjusting Device

(knob or switches) – for automatic or manual control of generator output voltage.

j) Automatic Synchronizing Device – for automatic synchronization of generator with an active bus.

k) Generator Strip Heater Contactor, Control Switch, and Indicator Light – to control generator strip heater. In addition, strip heater shall be interlocked to automatically de-energize when the generator is started. Control Switch shall also control jacket water heater (if provided).

l) Load Sensor and Contacts – or other means to provide the signal described in

Section 2.9 to CGMCS.

m) Voltage Sensing Device – or other means to provide the signal described in Section

2.10 to CGMCS.

n) Temperature Meter(s) and Selector Switch – or other means of monitoring temperatures of the generator windings.

4.4 Switchboard Distribution Section

4.4.1 The distribution section of the emergency switchboard shall contain circuit breakers for circuit protection of that portion of the 450-volt distribution system as shown on the plans and as required by the final design of the ship service distribution system.

4.5 Additional Switchboard Equipment

4.5.1 The following equipment, along with any other equipment required by the switchboard design but not listed previously, shall be installed in the switchboard (quantity 1 each unless otherwise indicated):

a) Bus Tie Circuit Breaker - tying emergency bus to ship service bus.

b) Ground Detection Test Switch and Indicator Lights (1 sets) or Line Insulation

Monitor – or other means to monitor the isolation from ground of the emergency bus.

c) Potential, current, and control transformers as required.

d) Fuse panel for fusing the potential, current, and control transformers and any other required circuits.

e) Parallel Selector Switch – or other means of selecting non-parallel, or paralleling of the emergency with the emergency bus (see Section 3.1.2(a)).

f) Parallel Mode Switch – or other means of selecting automatic or manual synchronization (see Section 3.1.2(b)).

g) Synchroscope – or other means to enable manual synchronization of a generator with an active bus.