Specifications

GUIDE SPECIFICATIONS— 538B,D OUTDOOR UNITS (cont)

2. Safeties:

a. System diagnostics.

b. Compressor motor current and temperature over-

load protection.

c. High pressure relief.

d. Outdoor fan failure protection.

H. Electrical Requirements:

1. Unit shall operate on single-phase, 60 Hz power at

115 v (538D009 only) or 208/230 v, or 3-phase, 60 Hz

power at 208/230 v or 460 v, as speciﬁed.

2. Unit electrical power shall be a single point

connection.

3. Unit control voltage to the indoor-fan coil shall be 24 v,

except 538D009 and 012 units, which shall supply line

voltage.

4. All power and control wiring must be installed per NEC

and all local building codes.

5. Unit shall have high- and low-voltage terminal block

connections.

I. Special Features (Field Installed):

1. Low-Ambient Kit:

Control shall regulate fan-motor cycles in response to

saturated condensing pressure of the unit. The control

shall be capable of maintaining a condensing tem-

perature of 100F±10Fwith outdoor temperatures to

–20 F. Installation of kit shall not require changing the

outdoor-fan motor.

2. Liquid Solenoid Valve:

This electronically operated shutoff valve shall close

and open in response to compressor operation. The

valve should be used with all long-lines applications

(over 100 ft).

3. Crankcase Heater (units with scroll compressors

only):

Unit shall be shipped with a clamp-on compressor oil

sump heater.