Circuit Breaker Test; Contactor Test - Danfoss VLT FC Series Service Manual

Test Procedures

8.4.9 Circuit Breaker Test

NOTICE
DRIVE TYPE
This test is applicable to only D1h–D8h drives.
The circuit breaker is optional. If present in a D-sized unit,
the circuit breaker is located in the option cabinet.
1. Use an ohmmeter set to read ohms.
2. Open the circuit breaker.
3. Measure the resistance across each of the 3
phases.
An open circuit (infinite resistance) is a correct reading. A
short circuit (0 Ω) indicates a problem with the circuit
breaker.
1. Close the circuit breaker.
2. Measure the resistance across each of the 3
8 8
phases.
A short circuit (0 Ω) is a correct reading. An open circuit
(infinite resistance), or high-resistance reading indicates a
problem with the circuit breaker.
If there is a problem with any of the phases, replace the
circuit breaker.

8.4.10 Contactor Test

NOTICE
OPTION AVAILABILITY
The contactor option is available only in D-sized drives.
The contactor is optional. If present, it is located in the
option cabinet. The contactor uses a customer-supplied
230 V AC control signal wired to the contactor coil. When
power is applied to the contactor coil, the contactor is
closed. When there is no power, the contact is open.
NOTICE
POWER REQUIREMENTS
Complete testing of the contactor requires an external
230 V AC supply.
104
®
VLT FC Series, D1h–D8h, Da2/Db2/Da4/Db4, E1h–E4h, J8/J9
Contactor test part I
1.
2.
An open circuit (infinite resistance) is a correct reading. A
short circuit (0 Ω) indicates a problem with the contactor.
Contactor test part II
1.
2.
A short circuit (0 Ω) is the proper reading. An open circuit
(infinite resistance) or high-resistance reading indicates a
problem with the contactor.
Contactor coil test
NOTICE
POWER REQUIREMENTS
Testing of the contactor coil requires 230 V AC power.
1.
2.
3.
When power is applied, the contactor energizes and is
engaged. A short circuit (0 Ω) is a correct reading. An open
circuit (infinite resistance) or high-resistance reading
indicates a problem with the contactor.
If there is a problem with any of the phases, replace the
contactor.
Danfoss A/S © 02/2019 All rights reserved.
Remove power to the contactor coil.
To measure across each of the 3 phases, use an
ohmmeter.
Manually engage the contactor.
With the contactor engaged, measure the
resistance across each of the 3 phases.
Apply power to the coil, energizing the contactor.
Use a voltmeter set to measure AC voltage
between A1 and A2 on TB6.
Measure the resistance across each of the 3
phrases.
MG94A502