4 Operation / Normal use
4 - 11
4.6 Remedying malfunctions in normal operation (continuation)
Fault
Possible Cause
Remedy
System starts
with difficulty
•
Time for
star-delta connec-
tion too long or too
short
•
Machine is under
compression
load
•
Voltage fluctua-
tions in the grid
•
Ambient temper-
ature
too low causing
excess viscosity
of oil
•
Oil is too viscous
Check and correct
time setting,
correct setting
3-6 seconds,
adjust on Relay K 1T
Determine reason
Check solenoid valve
and relief valve and
change if necessary
Heat installation loca-
tion
Select correct type of
oil: RENNER VDL N
ISO 68 or 46 for low
temperatures.
Compressor cuts
out before reaching
discharge pressure
•
Motor overload
tripping
•
Combistat cuts
out due to ex-
cessively high
temperature
•
Short circuit in
trip line
Check and adjust
overload setting;
check and adjust dis-
charge pressure
switch setting; check
supply lead for phase
failure.
Ensure correct cool-
ing; install new Com-
bistat if defective
Eliminate cause of
short circuit, change
defective fuse
Continued overleaf
Malfunctions
(contd.)