Table of Contents
Advertisement
4.2.6 Protection devices
Independently from the internal motor protection, fuses must be installed before the compressor.
The selection of fuses has to be done according to VDE 0635, DIN 57635, IEC 269-1 or
EN 60-269-1.
4.2.7 Crankcase heater
IMPORTANT
Oil dilution! Bearing malfunction! Turn the crankcase heater on 12 hours
before starting the compressor.
A crankcase heater is required with ZRH* and ZBH* horizontal Scroll compressors
configuration enables large amounts of refrigerant to condense in the compressor and to be
absorbed by the oil during standstill
charge exceeds 4.5 kg.
The crankcase heater must be turned on a minimum of 12 hours prior to starting the
compressor. This will prevent oil dilution and bearing stress on initial start-up.
The crankcase heater should be positioned on the right-hand side of the compressor, a few
centimetres away from the position of the electrical connection.
Caution: Crankcase heaters must be properly grounded!
4.3
Inverter operation
Copeland Scroll horizontal compressors ZRH49K* to ZRH72K* and ZBH30K* to ZBH45K* are limited
to fixed speed operation at either 50 or 60 Hz.
Compressor models ZRHV72K* and ZBHV45K* can be operated on inverter-derived power over the
range of 35 to 75 Hz. The inverter drives used to power these compressors must comply with the
provisions of technical specification IEC 600034-17. In particular, the motor input voltage must be
limited to 1.35 kV/microsecond line-to-line impulse voltage. These provisions are required to avoid
motor insulation breakdown, to limit motor heating, and to extend motor lifetime.
The compressor operating voltage must vary with frequency according to the diagram shown in
Figure 13. The value of the voltage should be 7.67 multiplied by the operating frequency over the
range of 35 to 60 Hz. From 60 to 75 Hz, the voltage should be a constant 460 volts. Matching voltage
to frequency according to these guidelines will prevent motor saturation and overheating.
Figure 13: Voltage versus operating frequency ZRHV72KJE-TFD and ZBHV45KJE-TFD
Operating compressor models ZRH49K* to ZRH72K* and ZBH30K* to ZBH45K* over a defined
frequency range will result in different application envelopes (see Figures 14 & 15). These envelopes
are more restricted at lower operating speeds. This is to prevent overloading and overheating of the
compressor motor during low-speed operation.
C6.2.7/1007-0619/E
periods. A crankcase heater is always required when the system
if the system
13
Advertisement
Table of Contents
