Specifications

MCD3000 Series

46 MG.15.A4.22 - VLT is a registered Danfoss trademark

Fault Procedure

• Disconnect the incoming supply (L1, L2, L3 and

control voltage) from the starter.

• Disconnect the motor cables (T1, T2,T3) from the

starter.

• Ensure the firing looms remain plugged in during

the tests.

• Using a 500 VDC insulation tester (low voltage

ohm meters or multi-meters are not adequate),

measure the resistance between the input and

output on each phase (L1-T1, L2-T2, L3-T3). The

resistance should be close to 33k

Ω.

• If the resistance measured across the SCR

measures below about 10k

Ω the SCR should be

replaced.

• If the resistance measured across the SCR is

greater than 33k

Ω there could be a control PCB

or firing loom fault.

CONTROL INPUT TEST;

This procedure verifies the integrity of circuits

connected to any of the remote control inputs. Start,

Stop, Reset and Par. Set.

• Using a volt meter measure across each input. If

24VDC is measured when the circuit is closed, the

switch/control is connected incorrectly or is faulty.