18
C6.3.1/0116-0716/E
4.6.2.2
Mechanical oil pressure switch
– ALCO FD-113ZU (A22 - 057)
Specifications for electro-mechanical oil pressure switches are as follows:
Cut-out pressure: 0.63 ± 0.14 bar
Cut-in pressure: 0.9 ± 0.1 bar
Time delay:
120 ± 15 sec.
The Alco Control FD-113ZU mechanical oil pressure switch operates with the above set points.
Legend:
11
..... Voltage connection
21
..... Control voltage connection
22
..... Control circuit
24
..... Alarm connection
A2
..... Oil pressure switch
A5
..... Compressor terminal box
R
....... Relay
N
....... Neutral connection
t
........ Time delay
Figure 17
Protection class: IP30.
4.7 Crankcase heaters
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. Heaters for 4M* and 6M* compressors are screwed into a sleeve (see
Figure 18
).
The crankcase heater is available in 120V, 230V and 480V.
The operation of 120V and 230V crankcase heaters is controlled by the CoreSense Diagnostics
module; this is not possible with 480V heaters.
Figure 18: 100 Watt crankcase heater element
