13
ELECTRICAL
Refer to electrical component box layout. See Fig. 15.
CAUTION
!
UNIT OPERATION HAZARD
Failure to follow this caution may result in equipment
damage and/or improper operation.
S
Field wiring must comply with local and national
electrical codes.
S
Power to the unit must be within the operating voltage
range indicated on the unit nameplate or on the
performance data sheet.
S
Operation of unit on improper line voltage or with
excessive phase imbalance will be hazardous to the unit,
constitutes abuse, and may void the warranty.
Properly sized fuses or HACR circuit breakers must be installed for
branch circuit protection. See unit nameplate for maximum fuse or
breaker size.
NOTE
:
Use copper wire only between disconnect switch and
unit.
The unit is provided with a concentric knock--out for attaching
common trade sizes of conduit, route power supply wiring through
this opening.
Always connect the ground lead to the grounding lug provided in
the control box and power leads to the line side of compressor
contactor as indicated on the wiring diagrams.
TRANSFORMER:
208/230 75VA
UPM CONTROL BOARD
RUN
CAPACITOR
GROUNDING
LUG
CONTACTOR:
2 POLE 2 THROW
A14180
Fig. 15 -- Electrical Component Box Layout
The electrical box is designed to allow servicing behind the box
relatively easily to access reversing valve, etc. The 2--3 screws on
the bottom of the electrical box could be removed and with wiring
all out one side of the box carefully swing box in direction of the
wiring bundle to allow access to components behind the box if
necessary. Remember that all sides of the cabinet are accessible but
in event the unit is placed where all sides make this difficult,
removal of the box may help.
The transformer is a 75va transformer which should provide ample
power for accessories. Size loads properly so they do not exceed
capability of the transformer.
The transformer allows 208/230V selection with the factory default
of 230V. The transformer has a 5amp circuit breaker internally
built in for class 2 rating.
The circuit board has a 3 amp fuse that should identify any issues
before the 5 amp circuit breaker trips. In an unlikely event of the
transformer 5 amp circuit breaker tripping, it has a manual reset.
Utility Curtailment
Utility curtailment is a voluntary energy saving program offered
through utility companies in some locations. Utility company will
provide the equipment that allows them to cut back demand on
equipment during peak demand times.
A qualified HVAC
technician should install the device to ensure system compatibility.
Refer to Fig. 16 for typical wiring to the UPM.
Systems using communicating user interface controls will set up
the control by entering the service screens, Setup and then select
Utility Curtailment.
There will be 3 options to enable or disable the curtailment:
1. Disabled: the utility curtailment, if wired into the UPM, will
be ignored.
2. *Low Stage: when utility curtailment relay opens, the unit
will only operate at low--stage.
3. *Off: when utility curtailment relay opens, the unit will
shut down until the utility relay closes.
* There will be a brief delay to cause the unit to stage or shut
down (approximately 0.40 to 1.20 minutes can be expected).
UTILITY RELAY
*
UTILITY SIGNAL
OPEN RELAY
* SUPPLIED BY UTILITY PROVIDER
A150166
Fig. 16 -- Utility Curtailment Wiring
