Specifications

Ventilation Air
Outside air may be required for ventilation. The temperature of the ventilation air must be controlled so that
mixture of outside air and return air entering the conditioner does not exceed application limits. It is also
general practice to close off the ventilation air system during unoccupied periods (night setback).
The ventilation air system is generally a separate building subsystem with distribution ductwork. Simple
introduction of the outside air into each return air plenum chamber reasonably close to the conditioner air
inlet is not only adequate, but also recommended. Do not duct outside air directly to the conditioner inlet.
Provide sufficient distance for thorough mixing of outside and return air.
General
1. Be sure the available power is the same voltage and phase as that shown on the unit serial plate. Line
and low voltage wiring must be done in accordance with local codes or the National Electrical Code,
whichever is applicable.
2. Apply correct line voltage to the unit. Two 7/8" (22mm) holes are supplied on the side of the unit. A
disconnect switch near the unit is repaired by code. Power to the unit must be sized correctly and have
time delay (dual element) fuses or a HACR circuit breaker for branch circuit overcurrent protection. See
the nameplate for correct ratings.
220-240 Volt operation and 50 cycle units
All 220-240 volt single and three-phase units are factory wired for 220 and 380 volt operation. For 240-volt
operation, the line voltage tap on the 18-volt transformer must be changed. Disconnect and cap the red lead
wire and interchange it with the orange lead wire on the primary of the 18-volt transformer. Three-phase 50
cycle units require a neutral wire for 220-240/1/50 power.
Fan speed change
All units have three-speed fan motors (HI, MID, LOW) and are shipped for HI, MID & LOW speeds operation.
On unit sizes 015 though 050, each fan motor is supplied with a 6-pin terminal block mounted on the fan
motor.
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