Table of Contents
Advertisement
.47
5/8" Hex
Core
(Part No. EC39EZ067)
Washer
O-Ring
1/2" Hex
This surface provides a metal to metal seal when
torqued into the seat. Appropriate handling is
required to not scratch or dent the surface.
Fig. 26 — CoreMax
Compressor Protection
COMPRESSOR OVERCURRENT
The compressor has internal limbered motor protection.
COMPRESSOR OVERTEMPERATURE PROTECTION (IP)
The compressor has an internal protector to protect it against ex-
cessively high discharge gas temperatures.
CRANKCASE HEATER
The heater prevents refrigerant migration and compressor oil dilu-
tion during shutdown whenever compressor is not operating. The
heater is wired to cycle with the compressor; the heater is off when
compressor is running, and on when compressor is off.
1. Third-party trademarks and logos are the property of their respective
owners.
Seat
1/2-20 UNF RH
0.596
30°
45°
Depressor per AHRI 720
+.01/-.035
From Face of Body
7/16-20 UNF RH
®1
Access Port Assembly
The crankcase heater will operate as long as the power circuit is
energized. The main disconnect must be on to energize the crank-
case heater.
IMPORTANT: Never open any switch or disconnect that
energizes the crankcase heater unless unit is being serviced
or is to be shut down for a prolonged period. After a pro-
longed shutdown on a service job, energize the crankcase
heater for 24 hours before starting the compressor.
HIGH PRESSURE SWITCH
The system is provided with a high pressure switch mounted on
the discharge line. The switch is stem-mounted and brazed into the
discharge tube. Trip setting is 630 ±10 psig (4344 ±69 kPa) when
hot. Reset is automatic at 505 ±20 psig (3482 ±140 kPa).
LOSS OF CHARGE SWITCH
The system is protected against a loss of charge and low evapora-
tor coil loading condition by a loss of charge switch located on the
liquid line. The switch is stem-mounted. Loss of Charge Switch
trip setting is 27 psig ±3 psig (186 ±21 kPa). Reset is automatic at
44 ±5 psig (303 ±35 kPa).
OUTDOOR FAN MOTOR PROTECTION
The outdoor fan motors are internally protected against
overtemperature.
CONTROL CIRCUIT, 24-V
The control circuit is protected against overcurrent conditions by
circuit breakers mounted on control transformer TRAN1 and
TRAN2. Reset is manual.
Commercial Defrost Control
The Commercial Defrost Control Board (DFB) coordinates ther-
mostat demands for one stage cooling, first stage heating, emer-
gency heating and defrost control with unit operating sequences.
See Fig. 28 for board arrangement.
The DFB is located in the 38AUQ unit's main control box (see
Fig. 27). All connections are factory-wired. Refer to Tables 13
and 14 for details of DFB Inputs and Outputs.
26
Advertisement
Table of Contents
