Stulz Tel-Air-2 Series, Operating Instructions Manual

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E/0618/35A/23
3.6 Control, Monitoring and Safety Components
All equipment is set and inspected at the factory and generally does not require further
adjustments or interventions.
If, for specific reasons, it becomes necessary to perform modifications on the settings of
automatic device this task must only be performed, subsequent to notification to the STULZ
engineering service, by specialized product expert.
STULZ air conditioner are equipped with a set of devices designed to ensure proper operation.
Intervention by any one of these automatic safety device is a sign of a malfunction and it is
absolutely necessary to eliminate the cause of the malfunction.
It is prohibited to make electrical by-passes on safety equipment. This intervention,
in addition to being dangerous, also immediately invalidates guarantee coverage
for the product.
Interrupt electrical power to the unit before performing any repair or maintenance.
Work on the unit must only be done by expert, qualified and authorized personnel.
High pressure safety switch
Stops compressor operation when the pressure inside the refrigeration circuit exceeds the
following value. OFF 29,5 bar ON 24,5 bar
Low pressure safety switch
Stops compressor operation when the pressure inside the refrigeration circuit drops below the
following value. OFF 0,4 bar ON 1,5 bar
Contactors
Control the motors by operating with auxiliary voltage. They refer to IEC947-4-1 standards.
Automatic circuit breakers
Protect against short circuits and excessive motor current. They have adjustable thermal and
magnetic triggering devices.
Mechanical safety thermostat of heating elements (if present)
Protects the heating elements by cutting off the power supply in case of excessive surface
temperature of the heating elements. The thermostat is adjusted to 90°C.
Autotransformer
This device is necessary, when the power supply voltage differs from the standard voltage. The
autotransformer adapts the supplied voltage to the standard voltage.
It is manufactured in compliance with EN60742 and CEI14-6 standards. When the space is
sufficient, it is installed in the unit.