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3.5
Crankcase heaters
CAUTION
Overheating and burnout! Compressor damage! Never ap ply power t o
the crankcase heater in free air, before the crankcase heater is installed on
the compressor or when it is not in complete contact wit h t he c ompressor
shell.
IMPORTANT
Oil dilution! Bearing malfunction! Turn the crankcase heater on 12 hours
bef ore starting the compressor.
A crankcase heater is used to prevent refrigerant from migrating into t he s hell d uring st andstill
periods. The installation of a
compressor charge limits
and configuration.
Compressor model
ZH04K1P & ZH05K1P
ZH06K1P to ZH12K1P
ZHI05K1P to ZHI14K1P
ZH15K1P & ZH19K1P
ZHI18K1P & ZHI23K1P
ZHI27K1P to ZHI46K1P
Table
3:
Refrigerant charge limit
Figure 6: Crankcase heater location, models ZH04K1P to ZH19K1P and ZHI05K1P to ZHI23K1P
Figure 7: Crankcase heater location, models ZHI27K1P to ZHI4 6K1P
The initial start-up in the field is a very critical period for any compressor because all load -bearing
surf aces are new and require a short break-in period to carry high loads under adverse conditions.
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 s tart -up. The crankcase
heater must remain energized during compressor off cycles.
NOTE:
Please refer to the Spare Parts list available at
gb/tools-resources
to select the correct crankcase heater model.
Caution: Crankcase heaters must be properly grounded!
For installation, the manufacturer/installer shall follow the recommendations mentioned below.
Assembly instructions
▪ Choose the appropriate model according to compressor size and required wattage.
▪ Check the compressor application guidelines for crankcase heater connection and operation.
▪ Position the crankcase heater between the lower cover and the lower bearing weld project ion
(Fig. 8).
AGL_HP_ST_ZHK1P_EN_Rev00
crankcase heater is required when the system c harg e ex ceeds the
indicated in Table 3.
This requirement is independent from syst em t ype
Refrigerant charge limit
Single compressor systems
3.6 kg
4.5 kg
4.5 kg
7 kg
For compressor models
ZHI05K1P to ZHI23K1P, the crankcase heat er must
be mounted 10 to 40 mm above compressor legs –
see Figure 6.
For compressor models ZHI27K1P to ZHI46K1P, t he
crankcase heater must be mounted below the oil
removal valve located on the bottom shell for tandem
versions – see Figure 7.
Refrigerant charge limit
Even Tandem systems
5.0 kg
6.3 kg
6.3 kg
10.9 kg
ZH04K1P to ZH19K1P and
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