138
ENABLING AND DISABLING COMPRESSORS —
Compressors in the 38AP units can be enabled or disabled in
the controls. To enable or disable a compressor, toggle the
value in the
Configuration
o
SERV
menu for each individual
compressor.
COMPRESSOR MOTOR PROTECTION — Two types of
motor protection are used on the scroll compressors.
Compressor Circuit Breakers — Compressors have a man-
ual reset, calibrated trip, magnetic circuit breaker for overcur-
rent protection. Do not bypass connections or increase the size
of the circuit breaker to correct trouble. Determine the cause
and correct it before resetting the breaker.
Advanced Scroll Temperature Protection (ASTP) — All
non-digital Copeland compressors are equipped with advanced
scroll temperature protection (ASTP). A label located above
the terminal box identifies models that contain this technology.
See Fig. 158.
Advanced scroll temperature protection is a form of internal
discharge temperature protection that unloads the scroll com-
pressor when the internal temperature reaches approximately
300 F (150 C). At this temperature, an internal bi-metal disk
valve opens and causes the scroll elements to separate, which
stops compression. Suction and discharge pressures balance
70
60
50
40
30
20
10
0
-10
-20
-30
Saturated Suction Temperature (°F)
80
60
70
80
90
100
110
120
130
140
150
160
Saturated Condensing
T
emperature (°F)
30
40
50
170
a38-7307
Fig. 156 — Compressor Operating Envelope, °F
Saturated Suction Temperature (°C)
Saturated Condensing
T
emperature (°C)
Fig. 157 — Compressor Operating Envelope, °C
Fig. 158 — Advanced Scroll Temperature
Protection Label
