Download APPENDIX F TECHNICAL SPECIFICATIONS

2.9.1
Panelboard Buses
Support bus bars independent of circuit breakers. Main buses and back pans shall be
designed so that breakers may be changed without machining, drilling or tapping. If
neutral circuit conductors are required, provide isolated neutral bus in each panel for
connection of circuit neutral conductors. Provide separate ground bus identified as
equipment grounding bus per UL 67 for connecting grounding conductors; bond to steel
cabinet. In addition to equipment grounding bus, provide second “isolated” ground bus,
where indicated. Provide copper panelboard buses.
2.9.2
Panelboard Circuit Breakers
2.9.2.1 General
UL 489, thermal magnetic-type having a minimum short-circuit current rating equal to
the short-circuit current rating of the panelboard in which the circuit breaker shall be
mounted. Breaker terminals shall be UL listed as suitable for type of conductor provided.
Series rated circuit breakers and plug-in circuit breakers are unacceptable.
2.9.2.2 Multiple Breakers
Common trip-type with single operating handle. Breaker design shall be such that
overload in one pole automatically causes all poles to open. Maintain phase sequence
throughout each panel so that any three adjacent breaker poles are connected to Phases A,
B, and C, respectively.
2.9.3
Panelboard Directory
Each panelboard shall have a directory with the name and number of the equipment
served by each circuit breaker which shall correspond with the final circuit arrangement.
The directory shall also indicate the panel designation, voltage and phase at the top.
Each directory shall be mounted inside the panelboard.
2.10
ENCLOSED CIRCUIT BREAKERS
Enclosed circuit breakers shall conform to UL 489. Individual molded case circuit
breakers shall have voltage and continuous current ratings, number of poles, overload trip
setting and short circuit current interrupting rating as indicated. Enclosure type shall be
as indicated.
2.11
FUSES
Fuses shall conform to NEMA FU 1. Time-current characteristics curves of fuses
serving motors or connected in series with circuit breakers shall be coordinated for
proper operation. Fuses shall have voltage rating not less than circuit voltage.
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