Stulz Tel-Air-2 Series, Operating Instructions Manual

Page: 65 / 72

E/0618/35A/65
12.5 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 condensate drain pan

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).
It's possible to install Winter kit option only in the units with refrigerant R407C.
12.6 Main switch - SWT/SWM
This is located on the electrical panel 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.
Setting of this component is made in factory and must not be altered. 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).
12.7 Socket connection field
– SCF
This option consists of connectors to allow a fast power supply connection. These connectors
replace the holes for passing electrical cables on the plate placed on the top of the unit, rear right
corner (for standard configuration of this plate, see Chapter Installation). Matching plugs to wire
power supply cables are provided with option ACTSKIT.
12.8 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.