Filter
Top Products
INDUSTRIAL GENERATOR SETS — APPLICATION & INSTALLATION MANUAL — REV. #4 (09/07/07) — PAGE 75
Electrical Terminations
Most engine-generators, whether located indoor or outdoors
are usually mounted on a concrete pad and typical electrical
terminations are brought up underneath the engine-generator
for final termination. This cable entry or “stub-up” underneath
the generator set provides for easy termination of the feeder
conductors and makes for a clean, professional looking
installation. Check code compliance before proceeding.
a) Separately Mounted Fuel Tank - When a separately
mounted fuel tank is used, the electrical stub-up
underneath the generator set is simplified because of
the open bottom design of the generator skid. The final
cable terminations rise from the stub-up entry location
underneath the engine-generator, in a close proximity to
the circuit breaker enclosure. When code required, these
feeders should be provided in suitable and properly sized
conduits that attach to the circuit breaker enclosure.
The feeder cables then connect directly to the output
lugs and/or bus bars provided on the main line circuit
breaker.
b) Subbase Mounted Fuel Tank - When a subbase fuel
tank is used (refer to Fuel System section), the tank
should be designed with a stub-up area on the generator-
end of the tank. This feature allows for an open area on
the tank assembly whereby electrical terminations can
be brought up underneath the engine-generator for final
termination, just like the open bottom design generator
skid. (This feature is standard for all MQ Power subbase
tanks and is typically a purchasable option from most
tank manufacturers) When code required, the feeder
conductors should be provided in suitable and properly
sized conduits that attach to the circuit breaker
enclosure. The feeder cables then connect directly to
the output lugs and/or bus bars provided on the main
line circuit breaker.
AC ELECTRICAL CONNECTIONS
If the engine-generator is fitted with a weatherproof
outdoor enclosure, it may be required to penetrate the
side of the generator housing to facilitate final cable
terminations. This will likely require special conduit,
fittings and hardware. The feeder conductors would enter
the housing on the side where the circuit breaker is
mounted. The feeder conductors would enter the circuit
breaker enclosure from the bottom, top or side as
necessary, to complete final cable terminations. Check
with the local inspection authority before proceeding.
Closed Bottom Generator - If the engine-generator is closed
bottom, such as in a sound attenuated design, the bottom
floor of the engine-generator must be cut to allow for a bottom
entry electrical stub-up. If this is not possible, it may be
required to route the feeder conductors on the outside of the
engine-generator to reach the circuit breaker enclosure. This
will likely require special conduit, fittings and hardware. The
feeder conductors would enter the housing on the side where
the circuit breaker is mounted. The feeder conductors would
enter the circuit breaker enclosure from the bottom, top or
side as necessary, to complete final cable terminations.
Check with the local inspection authority before proceeding.
c) Oversize Subbase Tank - Specification requirements
sometimes require an oversized tank to meet specific
generator run-time demands. This can cause difficulty
in completing final electrical connections. The tank
should be designed with a stub-up area on the generator-
end of the tank. However, depending on the placement
of the engine-generator on the tank, feeder terminations
may not rise in a close proximity to the circuit breaker
enclosure. This could require the feeder conductors to
enter the circuit breaker enclosure from the side or top,
necessitating special fittings and/or hardware.
Refer to National Electric Code (NEC)
Table 210.24 for specific circuit
breaker current ratings for various
size conductors.
NOTE
Refer to Table 25 “Main Line Circuit
Breaker Sizing Information” on page
85 for a complete listing of MQ Power
generator main line circuit breakers
available from the factory. This table
details information about circuit
breaker ampacity ratings, interrupt
capacity, quantity of conductors per phase & size of output
lugs available for each breaker, for each model MQ Power
Standby Generators.
NOTE