Instructions For "Thermal Relay (Bimetal Relay) - Arneg UCA Manuel D'installation Et De Service

INSTRUCTIONS FOR "THERMAL RELAY (BIMETAL RELAY)"

The thermal relay is one of the safety devices protecting the electric motor of the compressor from overloads or phase
outages.
This relay exploits the thermal effect of the passage of current on a bimetal to switch off a line if the current should
exceed the calibrated value for a set time.
The calibration value of the thermal relay for a nominal voltage of 400V, is shown in the table below:
Compressor Calibration
Amp
K 40 CC 1,6
K 75 CC 2,1
K 100 CC 2,6
K 180 CC 4,0
K 200 CC 5,0
K 235 CC 6,0
K 280 CC 6,0
K 400 CC 8,1
K 470 CC 9,9
K 500 CC 14,0
K 740 CC 15,0
K 750 CC 16,3
K 1000 CC 18,5
K 1500 CC 25,0
CASING PRESSURE REGULATOR TYPE "KVL"
Some condensing units for low temperature may be equipped with a KVL valve for which the following information is
of the valve housing.
CODE: 05050532 Edition 02 15-04-2003
05050532 03 11/02/2010
Use and Maintenance of Condensing Units
Compressor Calibration
Amp
K 50 CS 1,6
K 75 CS 2,1
K 100 CS 2,6
K 150 CS 3,0
K 180 CS 4,0
K 250 CS 5,0
K 300 CS 6,0
K 400 CS 8,1
K 470 CS 9,9
K 500 CS 14,0
K 750 CS 15,0
K 1000 CS 16,3
K 1500 CS 18,5
K 1500 CB 33,0
K 2500 CB 38,0
K 3000 CS 53,0
provided on the subject of installation and regulation.
The KVL casing pressure regulator should be installed on the intake line, as close
as possible to the compressor; its function is to limit the pressure of the casing so
that it never exceeds a set point while running.
This service to protect the compressor motor from overloads caused by excessive
intake pressure during startup after prolonged periods of disuse or after
defrosting. The KVL regulator makes it possible to use smaller electric motors
that, in the absence of the KVL would reduce the efficiency of the compressors
during normal operation, as a smaller motor can adapt better to the load. At the
same time it should be considered that increased efficiency means less heating of
the electric motor. This is very important for all those compressors where the
motor is mainly cooled by the cold gasses coming from the intake.
The KVL startup regulator opens as the pressure downstream decreases, for
example when the intake pressure upstream of the compressor falls below the
calibrated value. The KVL only regulates depending on the output pressure.
Changes in pressure at the input to the regulator do not affect its degree of
opening thanks to a small equalizing bellows. It has an active surface equal to that
Compressor Calibration
Amp
ZS 21 K4E 4,8
ZS 26 K4E 6,2
ZS 30 K4E 6,5
ZS 38 K4E 8,0
ZS 45 K4E 9,7
ZF 09 K4E 4,5
ZF 11 K4E 6,0
ZF 13 K4E 6,5
ZF 15 K4E 7,8
ZF 18 K4E 9,6
ZF 24 K4E 13,7
ZF 33 K4E 19,6
Technical Manual
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