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3.6
Crankcase heater
WARNING
Ignition source in a potentially flammable atmosphere! Fire hazard! The
crankcase heater, as specified by Emerson (see spare parts catalogue), is not
an ignition source during normal operation in A3 systems but could become
one if not installed properly according to installation instructions. Ensure
correct electrical and mechanical installation.
CAUTION
Overheating and burnout! Compressor damage! Never apply power to the
crankcase heater in free air, before the crankcase heater is installed on the
compressor or when it is not in complete contact with the compressor shell.
IMPORTANT
Oil dilution! Bearing malfunction! Turn the crankcase heater on 12 hours
before starting the compressor.
A crankcase heater is used to prevent refrigerant from migrating into the shell during standstill
periods. The installation of a crankcase heater is required when the system charge exceeds the
charge limits indicated in Table 7.
configuration.
Compressor model
ZH04KCU & ZH06KCU
ZH08KCU
ZH09KCU to ZH13KCU
Table 7: Refrigerant charge limits & crankcase heater position
The initial start-up in the field is a very critical period for any compressor because all load-bearing
surfaces 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 start-up. The crankcase
heater must remain energized during compressor off cycles.
Crankcase heaters to be used in ATEX Zone 2 locations must comply with the ATEX Directive
requirements. Non ATEX-certified crankcase heaters shall NOT be used in ATEX Zone 2 locations.
NOTE: The crankcase heater presently available from Emerson is not ATEX-certified and can
only be used in non-flammable environments.
from Emerson, please refer to the Copeland spare parts & accessories catalogue available at
www.climate.emerson.com/en-gb/tools-resources
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 projection
(Fig. 7).
▪ Fit the heater horizontally around the crankcase, ensuring that it is in close contact with the
compressor housing along the entire length.
▪ Avoid having the heating portion of the heater in contact with any weld projection (Fig. 8 & 9).
▪ Avoid having the assembly heater inclined (Fig. 10).
▪ Close the lock and tighten the screw, torque: 2 - 3 Nm.
▪ The excess clamp bracket may be trimmed. Sharp edges must not come into contact with wires.
10
This requirement is independent from system type and
Refrigerant
charge limit
(kg)
1.4
1.5
1.6
In case this
to select the correct model.
Crankcase heater
Height
Position
(mm)
5 - 12
9.5 - 41
crankcase heater
AGL_HP_ST_ZHKCU_EN_Rev01
has to be ordered
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