Carrier 69NT40-561-201 - Safety and Protective Devices

2−8T-364
Section 2.3 − ELECTRICAL DATA−CONTINUED
k. Humidity Sensor
Orange wire Power
Red wire Output
Brown wire Ground
Input voltage 5 VDC
Output voltage 0 to 3.3 VDC
Output voltage readings verses relative humidity (RH) percentage:
30% 0.99 V
50% 1.65 V
70% 2.31 V
90% 2.97 V
2.4 SAFETY AND PROTECTIVE DEVICES
Unit components are protected from damage by safety
and protective devices listed in Table 2−1. These de-
vices monitor the unit operating conditions and open a
set of electrical contacts when an unsafe condition oc-
curs.
Open safety switch contacts on either or both of devices
IP−CP or HPS will shut down the compressor.
Open safety switch contacts on device IP−CM will shut
down the condenser fan motor.
The entire refrigeration unit will shut down if one of the
following safety devices open: (a) circuit breaker(s); (b)
fuse (F3A/F3B, 7.5A); or (c) evaporator fan motor in-
ternal protector(s) − (IP).
Table 2−1 Safety and Protective Devices
UNSAFE CONDITION DEVICE DEVICE SETTING
Circuit Breaker (CB−1, 25 amp) − Manual Reset Trips at 29 amps (460 VAC)
Excessive current draw in the
control circuit
Fuse (F3A & F3B) 7.5 amp rating
Excessive current draw by the
controller
Fuse (F1 & F2) 5 amp rating
Excessive current draw by the
Emergency Bypass module
Fuse (FEB) 10 amp rating
Excessive condenser fan
motor winding temperature
Internal Protector (IP−CM) − Automatic Reset N/A
Excessive compressor motor
winding temperature
Internal Protector (IP−CP) − Automatic Reset N/A
Excessive evaporator fan
motor(s) winding temperature
Internal Protector(s) (IP−EM) − Automatic Reset N/A
Abnormal pressures/tempera-
tures in the high refrigerant
side
Fusible Plug − Used on the Receiver 99C = (210F)
Abnormally high discharge
pressure
High Pressure Switch (HPS)
Opens at 25 kg/cm
2
(356 psig)