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© STULZ SpA . – all rights reserved EN/36B/08.2018
11.5. Electric reheat – RSC
This option is used to heat internal air. Electric heaters are made of aluminium and include a
safety thermostat. Heaters are controlled directly by C2020. Heaters are divided in single-phase
modules, each with 1,5 kW heating capacity and 6,52 A current absorption at nominal voltage. The
distribution of modules on the three lines of power supply is shown on the wiring diagram of the unit.
Heating resistance doesn’t require any specific maintenance operations but the periodic check of
their fixation to supports and their cleanliness. This check has to be done together with the general
check of the unit.
11.6. Crankcase heater for compressor – CRA
This heating resistance, installed around compressor carter, operates when compressor is OFF,
to keep lubricating oil warm. This function assures constant lubricating performance of oil at the
compressor start. It is necessary only when outdoor temperature might go below -20°C.
11.7. Kit for low external temperatures – WINTER KIT
When minimum outdoor temperature is below -25°C and cooling function is still required, units must
be provided with this option. With this kit, minimum outdoor working temperature is -40°C. The kit is
installed in factory and is composed of:
• condenser fan with special bearings for low temperature
• heating resistance on electrical box
• heating resistance on free cooling damper (when present)
• pressure transducer on condenser
• condenser shut system
• crankcase heater (so there is no need to order it separately).
INFORMATION
It’s possible to install Winter kit option only in the units with refrigerant R407C.
11.8. Main switch - SWT/SWM
This is located on the electric box and is used to disconnect main power supply to the unit. When
switched off, it interrupts power supply to the unit circuits from it downstream. This switch can be
provided by the installer as well, or it can be requested ordering this option. SWT is the version for
3-phase main power supply, SWM the version for single-phase main power supply. Main switch
doesn’t disconnect DC voltage, if present.
DANGER
ATTENTION: In case of main switch, the power supply cables between the connection terminals
of the customer and the main switch are always under voltage also if the main switch is open.
The supply cables are identified with the symbol below (high voltage).
