Carrier Streamline Scroll 69NT20-531-300 User Manual

Page 22

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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)

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