32
IMM AGS-2
Electrical Data
Field Wiring
General
Wiring must comply with all applicable codes and ordinances. Warranty does not cover
damage to the equipment caused by wiring not complying with specifications.
An open fuse indicates a short, ground, or overload. Before replacing a fuse or restarting a
compressor or fan motor, the trouble must be found and corrected.
Copper wire is required for all power lead terminations at the unit, and copper must be used for
all other wiring to the unit.
AGS units can be ordered with main power wiring for either multiple-point power (standard)
or single-point connection (optional).
If the standard multiple-point power wiring is ordered, two separate power connections are
made to power blocks (or optional circuit breaker disconnects) in power panel. See the
dimension drawings beginning on page 29 for entry locations. Separate disconnects are
required for each electrical circuit if the McQuay optional factory-mounted disconnects are not
ordered.
If the optional single-point power connection is ordered, a single power connection is made to
a power block (or optional circuit breaker disconnect) in the unit power panel. A separate
disconnect is required if the McQuay optional factory-mounted disconnect is not ordered.
Isolation circuit breakers for each circuit are included.
It can be desirable to have the unit evaporator heaters on a separate disconnect switch from the
main unit power supply so that the unit power can be shut down without defeating the freeze
protection provided by the evaporator heaters. See the field wiring diagram on page 42 for
connection details.
The 115-volt control transformer is factory mounted and wired.
CAUTION
If a separate disconnect is used for the 115V supply to the unit, it must power the entire
control circuit, not just the evaporator heaters. It must be clearly marked so that it is not
accidentally shut off during cold seasons. Freeze damage to the evaporator could result.
If the evaporator is drained for winter freeze protection, the heaters must be
de-energized
to prevent heater burnout.
CAUTION
AGS unit compressors are single-direction rotation compressors and can be damaged if
rotated in the wrong direction. For this reason, proper phasing of electrical power is
important. Electrical phasing must be A, B, C for electrical phases 1, 2 and 3 (A=L1,
B=L2, C=L3) for single or multiple point wiring arrangements. The solid-state starters
contain phase reversal protection.
DO NOT ALTER THE WIRING TO THE
STARTERS.