Technical data

18
Discharge gas thermostat
(30GH/GZ 015/035) - electromechanical version or units
with low-temperature option
A sensor in each compressor discharge line opens to shut down
the compressor if the discharge gas temperature exceeds the
preset level.
Cut out 146°C Cut in 113°C
Crankcase heater
The compressor is fitted with an electric resistance crankcase
heater which prevents the absorption of refrigerant by the
compressor lubricating oil when the compressor is shut down.
Each heater is held in place by a screw clip which must be
secure. Prolonged exposure of the heater to air will result in its
destruction. The heater is energized when the compressor is
switched off.
WARNING: Never open or disconnect any switch which will
cut the supply to the heaters, unless the unit is to be shut down
for lengthy service or repair or for a seasonal shut down. In all
cases the heater must be energised for at least 24 hours before
a compressor is restarted.
Compressor protection circuit board (STARTERGUARD)
- 30GH/GZ 015-035
The purpose of this card is to monitor the compressor operat-
ing environment, in particular:
• the crankcase heaters
• the contactors
• the part winding start timer
• the control wiring between these components
The status of the controlled components is displayed via three
different-coloured LEDs:
• Green LED: correct operation
• Orange LED: signals that the magnetic loop of the card
has detected the presence of a current, either in the
compressor crankcase heater or in the compressor motor.
If the green and orange LEDs are illuminated together,
this indicates that there is no fault.
• Red LED - fault related to:
- the heater, if the orange LED is not lit
- the contactor or the power line of the compressor
motor, if the orange LED is lit
If a fault is detected, the compressor is shut down.
Power supply and resetting:
The STARTERGUARD card uses 24 V AC ± 10%, 50 Hz or
60 Hz. When a fault occurs, the 24 V supply must be
interrupted and then restored, in order to reset the card. The
green LED lights up.
• Significant undercharge (large bubbles in the sight glass,
drop in suction pressure).
- Small units (charge below 20 kg per circuit).
After detection and repair completely drain the
refrigerant charge, using a refrigerant recovery unit,
then recharge completely, following the precautions
given above.
- Large units (charge above 20 kg per circuit).
After detection and repair completely recharge the unit
as described above, operate it for a few minutes and
then let a specialist carry out a chromatographic
analysis to verify the composition of the blend
(range: R-32: 22-24%, R-125: 23-27%, R-134a: 50-54%).
Compressors
Checking the oil charge
Check the oil level and add or remove oil as necessary so that
the level is 1/8 to 3/8 up each sight glass with the compressors
running normally.
WARNING: Use only oils which have been approved for use in
refrigeration compressors. Never use oil which has been
exposed to air.
Recommended oil:
39GH units (semi-hermetic compressors):
- Mineral oil, Carrier specification No. PP 33-02
- Suniso 3 GS (Sun Oil Co)
- Clavus G 32 (Shell Oil Co)
- Gargoyle Artic 155 (Mobil Oil) - Carrier reference 470 EE
as original charge, in 5 liter containers
30GZ units (semi-hermetic compressors):
- Poyester oil without additives (POE), Carrier
specification No. PP 47-26
- Mobil EAL Artic 68 - Carrier reference P 903 EAL
6805EE, in 4 liter containers.
WARNING: All fixing devices and fittings which may have
been removed during servicing must always be replaced upon
completion of the work and before restarting the unit.
Tightening torques to be applied
Description Diameter, mm Torque, Nm
Discharge valve M16 135-140
Cylinder head M12 75-87
Suction and liquid line flange M12 75-87
Suction valve M16 135-140
Compressor motor protection
Circuit breaker
Calibrated, thermo-magnetic, manually-reset circuit breaker
protects the compressors against locked rotors and overloads. It
also offers protection against excessive current draw up to the
trip capacity given in the wiring diagram.
WARNING: Never bypass a circuit breaker or increase its
setting. If a circuit breaker trips, find out why it has done so
and correct the problem before resetting the breaker.