Carrier 69NT20-531-300 manual Safety and Protective Devices

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
	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	Fuse (F3)	10 amp rating
control circuit
Excessive current draw by the	Fuse (F1 & F2)	5 amp rating
controller
Excessive current draw by the	Fuse (F4)	10 amp rating
expansion module
Excessive condenser fan mo-	Internal Protector (IP-CM) - Automatic Reset	N/A
tor winding temperature
Excessive compressor motor	Internal Protector (IP-CP) - Automatic Reset	N/A
winding temperature
Excessive evaporator fan mo-	Internal Protector(s) (IP-EM) - Automatic Reset	N/A
tor(s) winding temperature
Abnormal pressures/tempera-	Fusible Plug - Used on the Receiver	93 _C = (200 _F)
tures in the high refrigerant	Rupture Disc - Used on the Water-Cooled Con-	35 kg/cm@ = (500 psig)
side
	denser
Abnormally high discharge	High Pressure Switch (HPS)	Opens at 25 kg/cm@
pressure		(350 psig)

T-309 2-8