Emerson ZB Copeland Scroll Service Manual download pdf (Page 6)

ZB Series

Application guide

Configuration of the scroll compressor

Type of compressor

Built-in pressure Discharge temperature Unidirectional discharge

Motor protection

relief valve protection valve

ZB15-ZB45 IPR TOD Yes Neutral protection

ZB50-ZB88 IPR ASTP Yes Neutral protection

ZB92-ZB11M NA

Built-in sensor

External protection

for discharge temperature

module of motor +

Built-in sensor

Internal Pressure Release valve (IPR)

A built-in relief pressure valve is mounted between the high-

pressure and low-pressure side of the compressor. If the pressure

difference between the high- and low-pressure exceeds 26-32bar,

the internal pressure release valve opens. At the same time, the

hot discharge gas comes in contact with the temperature sensor

of the motor protector. As a result, the internal motor protector

trips. Once the compressor has cooled, the motor protector can

be reset.

Models ZB92 and ZB11M do not have the in-built pressure relief

valve. In order to ensure safe operation, the system configuration

should include a high-pressure switch whose setting pressure

does not exceed 30bar (gauge pressure).

Internal temperature protection

Therm-O-Disc (TOD) or ASTP is a temperature-sensitive snap disc

device installed at the scroll outlet. If the discharge temperature is

excessively high, the valve will open to allow the high-

temperature suction gas to return and contact with the motor

protection, so as to protect the compressor.

Motor protection module

Both ZB92 and ZB11M motor protection systems include an

external protection module for the motor. The module is connected

with four thermistors in series built into the motor windings and a

fifth thermistor mounted at the internal discharge port of the scroll

disks. If either motor or discharge temperature exceeds the limit

value, the module will trip and can only be reset after 30 minutes.

(Note: if the power supply of the module is cut off, the module will

reset at once.) The time-delay is set at 30 minutes in order for the

scroll compressor to cool down fully. If the compressor is restarted

without a time-delay, a destructive temperature-surge will be

caused in the compressor. For this reason, the power supply of the

module must not be clubbed together with the control circuit (see

also the schematic wiring diagram).

1 2 3 4 5 6 7 8 9 10 11 ... 46 47

Comments to this Manuals

No comments

Emerson ZB Copeland Scroll Service Manual Page 6

Comments to this Manuals

Related products and manuals for Air compressors Emerson ZB Copeland Scroll