Denford Software & Machines

Does anyone know what voltage is required to activate the main contactor switch that sends power to the drives, I there is a constant live to one side, but believe the main contact is activated via the a1 contact, when I push the grey button down on the top power comes out to the drives and transformer but it wont stay down.

There will most likely be a diagram on the side of the contactor.
It'll give the main contact ratings , auxiliary contact ratings (usually smaller and lower current carrying capacity) and what the coil needs to be energised
(eg, A1 - A2 24V DC would be the coil, 230V - 2.2Kw will be the contact rating)

This is what it reads on the side, but cant see what input voltage should be, I know the output is 220-250v ac?

As this is a basic magnet type contactor the power input from A1 reacts to A2 and pushes the magnet apart causing the circuits to open and power is diverted to the relevant connections? Is that a correct understanding?

Studying the label on the side -

The info at the top is the power coming into contacts A1/A2 > then the diragram to show which connectors join which > and then the output voltage. Is that correct?

So if A1 is 220vac in, what would A2 be in order to make the magnet seperate and open the circuit

I would expect A1/A2 is the operating coil, and it should be 240v ac. The contactor is just a set of changeover contacts like a relay.

If A1 is 220Vac then A2 would be neutral to energise the contactor (ie make it switch and make contact between L1>T1 L2>T2 L3>T3)

13 and 14 are a normally open auxiliary contact which can be used to signal that the contactor has physically changed state...used for safety interlocking as the main contactors can burn out, weld together or simply get stuck

That would explain the blk/w cable attached to A2, intially I assumed it was a neutral coming out of A2 to skt.c6 to the lube pump, but now realise that neutral came from the old main pcb through skt.c6 to the lube pump and A2.

Thanx guys very helpful, I'll try the theory out later.

Excellent. It worked, now have my drives powered up.

Onto the steppers......