Carrier 69NT40-541-306, Операция и обслуживание

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3–9 T-354
3.4 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.
h. 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
i. Controller Setpoint Range -30 to +30

C (-22 to +86

F)
Table 3–3 Safety and Protective Devices
UNSAFE CONDITION SAFETY DEVICE DEVICE SETTING
Excessive current draw
Circuit Breaker (CB-1) - Manual Reset Trips at 29 amps (460 VAC)
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 (F3A & F3B) 7.5 amp rating
Excessive current draw by the
controller
Fuse (F1 & F2) 5 amp rating
Excessive current draw by the
emergency defrost circuit
Fuse (FED) 5 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 /
temperatures in the
high refrigerant side
Fusible Plug - Used on the Receiver 99

C = (210

F)
Rupture Disc - Used on the
Water-Cooled Condenser
35 kg/cm

= (500 psig)
Abnormally high discharge
pressure
High Pressure Switch (HPS)
Opens at 25 kg/cm

(350 psig)
Table 3–2 Electrical Data (Continued)