Carrier Streamline Scroll 69NT20-531-300 User Manual
Page 22

2-8
T-309
PARAGRAPH 2.3 -- Continued
Orange wire
Power
Red wire
Output
Brown wire
Ground
Input voltage
5 vdc
g Humidity Sensor
Output voltage
0 to 3.3 vdc
g. Humidity Sensor
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 the following table.
These devices monitor the unit operating conditions and
open a set of electrical contacts when an unsafe
condition occurs.
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 (F3/15A); or (c) Evaporator Fan Motor Internal
Protector(s) -- (IP-EM).
Table 2-1 Safety and Protective Devices
UNSAFE CONDITION
DEVICE
DEVICE SETTING
Circuit Breaker (CB-1) -- Manual Reset
Trips at 29 amps (460 vac)
Excessive current draw
Circuit Breaker (CB-2, 50 amp) --Manual Reset
Trips at 62.5 amps (230 vac)
Circuit Breaker (CB-2, 70 amp) --Manual Reset
Trips at 87.5 amps (230 vac)
Excessive current draw in the
control circuit
Fuse (F3)
10 amp rating
Excessive current draw by the
controller
Fuse (F1 & F2)
5 amp rating
Excessive current draw by the
expansion module
Fuse (F4)
10 amp rating
Excessive condenser fan mo-
tor 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 mo-
tor(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
Rupture Disc -- Used on the Water-Cooled Con-
denser
93 _C = (200 _F)
35 kg/cm@ = (500 psig)
Abnormally high discharge
pressure
High Pressure Switch (HPS)
Opens at 25 kg/cm@
(350 psig)