Help on fault finding on a C3-31 Hammer combination machine

[EddyCurrent]

I was thinking you could have bought the brake unit direct from Klinger Born.
I'll send a pm about the spares, many thanks.

[OMLCNC]

So new complete enclosure arrived. Wired it in.

Guess what - no better than before. Still chattering contacts before they stay in and machine runs.

Have talked to Felder, they have no answers.

Talked to Transwave after checking I have 400V+ on all pin to pin connections at plug and in machine.
They are of the opinion that there is no problem with the Transwave unit. It would have to be returned to
them if there was. Especially as other two machines I have work fine.

Have returned the machine to a usable condition, just with chattering contacts before it runs.

Any more help suggestions gratefully received, to solve this annoying mystery.

[EddyCurrent]

Parts arrived today, many thanks but I hope I don't need them

I wonder if there is a bad contact somewhere and the vibration of starting up is moving it ? but why did it start okay with the brake unit disconnected ?

[m_c]

Eddy, you might find the braking circuit was cutting in with the chattering, and adding to the problem.

You really need to measure voltages.
The transformer should produce 230V, and the contactor needs 230V.

We already know the contactor isn't getting 230V, so you need to measure things, and see where the voltage is dropping.
Start at the transformer. Does the output voltage drop significantly when trying to start the machine?
If it does, then measure the input voltage.
If it doesn't drop, then you need to work your way through the various things that can control the 230V on it's route from the transformer to the contactor.

[EddyCurrent]

I can't see why the braking circuit is affecting it, especially when a new part from the manufacturer results in the same probelm.
I have drawn out the coil circuit for the contactor and I'll post it tomorrow all being well.
As you say, I would normally start at the supply, but as we have found this does not give results you would expect from a standard 3 phase supply.

Unfortunately I am 340 miles from the OP otherwise I would be round there to assist.

[m_c]

What you might find, is with the braking circuit disconnected, the contactor is still chattering, but as you've not got the braking system cutting in during the chattering, the chattering is not as pronounced or lasting as long.

Although the 3 phase won't give voltages in relation to ground like you'd expect, the measurements between legs should still be very similar to standard 3 phase.

[OMLCNC]

Thank you for suggestions, I will give it another go next week when I'm back in the workshop.

With no motors connected the contactor works fine and the brake (buzzing if stop pressed) so brake cutting in when trying to start motors idea is a strong possibility.