AGL_Ref_ST_YBK1E_EN_Rev01
11
3.6
Crankcase heater
WARNING
Ignition source in a potentially flammable atmosphere! Fire hazard!
The
crankcase heater is not an ignition source during normal operation in A2L
systems but could become one when 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 f ree air, bef ore 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
bef ore starting the compressor.
A crankcase heater is used to prevent ref rigerant f rom 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 9
.
This requirement is independent f rom system type and
conf iguration.
Compressor model
Refrigerant
charge limit
(kg)
Crankcase heater
Position
Height
(mm)
YB12K1E to YB24K1E
1.54
10 - 40
YB31K1E & YB36K1E
1.93
Table 9: Refrigerant charge limits & crankcase heater position
The initial start-up in the field is a very critical moment 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 start -up.
The crankcase
heater must remain energized during compressor off cycles.
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. 6)
.
▪
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. 7 & 8)
.
▪
Avoid having the assembly heater inclined
(Fig. 9)
.
▪
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.
▪
The presence of the heater shall be made evident by the posting of caution signs or markings at
appropriate locations.
Figure 6 Figure 7
Figure 8
Figure 9
