26 24 16 - Panelboards.pdf

26 24 16 - PANELBOARDS

Herbert, Rowland & Grubic, Inc. 26 24 16 -1 005153.0436

SECTION 26 24 16 - PANELBOARDS

PART 1 - GENERAL

1.1 SECTION INCLUDES

A. Power Panelboards (PP).

B. General Panelboards (GP).

C. Integral surge protection (SPD) devices.

1.2 RELATED SECTIONS

A. Division 26.

1.3 REFERENCES

A. UL listed panelboards and panelboard enclosures shall meet or exceed NEMA Standard

PB-1 and Federal Specifications W-P-115b, Type 1, Class 1, and be listed as service entrance equipment when used as such.

B. The following specifications and standards are incorporated by reference:

1. Underwriters Laboratories, Inc. (UL) Publications:

No. 50 Cabinets and Boxes, Electrical

No. 67 Panelboards

No. 489 Molded Case Circuit Breakers and Circuit Breaker Enclosures

2. National Electrical Manufacturers Association (NEMA) Publications:

No. PB1 Panelboards

No. AB1 Molded Case Circuit Breakers

1.4 SUBMITTALS

A. Submittals shall be made in accordance with Section 26 05 00 - Electrical-General.

B. Submit shop drawings for all panelboards in this Section.

C. Include all construction and device characteristics to show compliance with specifications.

Submittal shall include, but not be limited to, the following:

1. Main bus ampacity.

2. Construction details.

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3. UL listing.

4. Protective ratings and withstand ratings.

5. Circuit Breakers:

a. Type.

b. Ratings and withstand ratings.

6. Enclosure NEMA type.

7. Integral TVSS Equipment.

1.5 PROJECT RECORD DOCUMENTS

A. Record actual locations of products; indicate actual branch circuit arrangement, and loadings for each panelboard.

B. Provide a directory for each panelboard giving the circuit breaker number and the name or description for the load on that circuit.

1.6 OPERATION AND MAINTENANCE DATA

A. Maintenance Data - Include spare parts data listing; source and current prices of replacement parts and supplies; and recommended maintenance procedures and schedules.

1.7 QUALITY ASSURANCE

A. Perform work in accordance with National Electrical Contractors Association Standard of

Installation.

1.8 FIELD MEASUREMENTS

A. Verify that the panelboard will fit in the space allocated on the plans.

1.9 EXTRA MATERIALS

A. Spare Circuit Breakers:

1. Refer to panel schedules within the contract drawings for quantities and trip ratings of spare circuit breakers to be provided.

B. Provide two of each panelboard key.

PART 2 - PRODUCTS

2.1 PANELBOARDS - GENERAL

A. Interiors:

Herbert, Rowland & Grubic, Inc. 26 24 16 -3 005153.0436

1. Completely factory assembled.

2. Independent switching and protective devices.

3. Replaceable circuit breakers with machining, drilling, or tapping.

4. Double row construction.

5. Full-sized, insulated, copper, neutral bars.

6. In subfed panels, provide neutral isolated from ground.

7. Arrange bus bar taps for panels with single pole branches for “distributed phase” or “phase sequencing.”

8. Full-sized copper, ground bus.

B. Panelboard Boxes:

1. NEMA rating in accordance with Section 26 27 16 - Control Panels and Enclosures.

2. Minimum 20 inches wide.

3. Without knockouts.

4. At least minimum gutter space per NEC.

5. At least four interior mounting studs with adjustable nuts.

C. Trim conforming to the following:

1. Accessible switching device handles.

2. Barriers for completely dead-front construction.

3. Concealed door hinges.

4. Chrome plated, minimum projection latch.

5. Key lock on panelboards; all locks keyed alike.

6. Three-point closure on doors over 48 inches high.

7. Permanent directory with heavy plastic cover.

8. Flush panel trim with 3/4-inch overlap on all four sides.

9. Trim clamps inaccessible when door is closed.

D. Bus Bars:

1. Main bus bars in tin plated copper.

2. Sized in accordance with UL Standards.

3. Limit of temperature rise on any current carrying part - 50 degrees above air ambient of 40 degrees C maximum.

E. Surge Protection (SPD) Devices:

1. Provide 120 kA integral SPD for all 240/120 panelboards shown on the contract drawings.

2.2 480/277 VAC, 3 PHASE PANELBOARDS (PP)

A. General:

1. Definition - Panelboards are to operate on 480Y/277 volt, 3 phase power. The panel may contain circuit breakers to power lighting.

2. Panelboard Breakers - Molded case, thermal magnetic trip, bolt-on connection, quick-make, quick-break, toggle handle circuit breakers. Two- and three-pole units to be internal common trip type with silver alloy contacts.

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3. Main Circuit Breakers - Rated at 35,000 A.I.C. (or 65,000 A.I.C. where noted on the Contract Drawings)

4. Panelboards for use at 480 or 600 volts AC maximum to incorporate branch circuit breakers as shown or scheduled rated at 35,000 A.I.C. symmetrical at 480 volts.

2.3 208/120VAC, 3 PHASE PANELBOARDS (PP)

A. Application - Provide panelboards as indicated in the Contract Documents.

B. Description:

1. Operating Voltage - 208Y/120 volts, 3 phase power as scheduled.

2. The panelboards may contain circuit breakers to power equipment other than lighting and receptacles.

C. Circuit breakers shall be:

1. Molded case, thermal magnetic trip, bolt-on connection.

2. Quick make, quick break, toggle handle.

3. Silver alloy contacts.

4. Two- and three-pole units shall have internal common trip.

5. Rating - 22,000 A.I.C. (or 14,000 A.I.C. where noted on the Contract Drawings).

D. For panelboards up to 240 volts, incorporate branch circuit breakers rated at 10k A.I.S.

symmetrical at 240 volts.

E. Provide panelboards with circuit protective devices as scheduled on the Contract

Drawings.

F. Manufacturers:

1. Square D

2. Eaton

3. Or equal.

2.4 240/120VAC, 1 PHASE PANELBOARDS (LP)

A. Application - Provide panelboards as indicated in the Contract Documents.

B. Description:

1. Operating Voltage – 240/120 volts, 1 phase power as scheduled.

2. The panelboards may contain circuit breakers to power equipment other than lighting and receptacles.

C. Circuit breakers shall be:

1. Molded case, thermal magnetic trip, bolt-on connection.

2. Quick make, quick break, toggle handle.

3. Silver alloy contacts.

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4. Two-pole units shall have internal common trip.

5. Rating - 22,000 A.I.C. (or 14,000 A.I.C. where noted on the Contract Drawings).

D. Provide panelboards with circuit protective devices as scheduled on the Contract

Drawings.

PART 3 - EXECUTION

3.1 PANELBOARDS

A. Incorporate panelboard within box. Increase box width as required for additional space for auxiliary equipment, subfeeds or controls. Minimum depth 5-3/4 inches; increase if required to maintain 2 inches between edge of knockouts and front edge of cabinet. Height of cabinet as required. Maximum mounting height to top of cabinet is

72 inches. Locate panels as shown on the Contract Drawings.

B. Contractor shall include field time to install/replace panelboard circuit breakers with the spare parts to accommodate coordination issues with the process, HVAC, or other equipment ratings for the project.

3.2 IDENTIFICATION

A. Identification shall be in accordance with Section 26 05 53 - Electrical System

Identification.

3.3 LOADING

A. Panelboards shall be loaded evenly on each phase. Maximum imbalance shall be limited between phases (i.e., 3-4-5 is not acceptable; 4-5-4 is acceptable). Contractor shall measure steady state load currents at each panelboard feeder and rearrange circuits in the panelboard to balance phase loads within 10% of each other.

3.4 MOUNTING

A. Top of panel not to exceed 66 inches.

B. Methods and Materials - Per Section 26 05 29 - Electrical Supports, Anchors, and

Fasteners and manufacturer’s requirements.

END OF SECTION