Motor Overload Relay Adjustment And Changing - KAESER SK 19 Service Manual

7.5

Motor Overload Relay Adjustment and Changing

Attention!
The relay is set to the standard adjustment at the factory.
Compressor motor: Wye -- delta start
Overload relays set points see wiring diagram.
In the Wye---delta configuration the phase current is fed through the motor overload relay.
This phase current is 0.58 times the nominal motor current.
For the nominal motor current see motor nameplate.
Adjustment:
To prevent the overload relay from tripping (because of voltage fluctuations, temperature
influences or component tolerances), the value can be set up to 15% higher than the
calculated phase current.
Attention!
Lock the main disconnect in the "off" position in accordance with ap-
plicable lock out/tag out procedures (example: OSHA CFR 29
§ 910.147) to ensure that the compressor does not restart. See chap-
ter 2.3 for the main disconnect switch.
The power supply voltage (see circuit diagram) must be fitted and con-
nected with the compatible motor overload relay, and the set point
must be adjusted.
If the power supply voltage is changed, the jumpers inside the motor
terminal box, the motor overload relay and the cutout in the control
cabinet must be changed.
Motor terminal block
Low voltage
230V
U6
V6 W6
V2 W2
U2
V5 W5
U5
U1 W1
V1
Motor terminal block
High voltage
460V
U6
V6
U2 V2
Jumper
U5
V5
U1
V1
Initial Start
W6
W2
W5
W1
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