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

[m_c]

From putting the meter over A1, A2 on the contactor and pressing the start button the voltage is not instant ie it climbs to 240v while it chatters,
same if you put it over any of the other contacts. When it pulls in it is 240v. So readings might be 50, 70, 130, 170 then 240v (all while chattering)

Is there a way of wiring out the braking board item 7 on the drawing and still making the machine work to eliminate it from being the problem?
I can disconnect wire 24 from the contactor to stop it breaking, but there are 5 other wires still connected.

Then I can happily spend the £500 knowing that that is the cause.

The readings are what I suspected you'd get, especially with a multimeter.
What about the input voltage to the transformer?
If they also drop, what about the main supply into the machine?


What I can't really make out from the wiring diagram, is are the top right wires, and lower left side wires on the braking module directly connected (I'm guessing each wire has a separate terminal, but are the terminals paired together? - A photo might help)

However, I think if you remove the link between R8 and 4 on the contactor, it'll be enough to break the circuit for the braking.
Do you have a diagram for the selector switch, as it would help understand exactly what's going on?

Assuming the selector switch is just a switch, with no relays/contactors to control things, then the key to the braking circuit is how the 3rd leg is handled. It is controlled via the auxiliary contact (other two legs go via the main contacts, with the third main contact used as the latch for the start button - the start button second contact also bypasses the aux. contact, which I assume also ensures the braking module remain inactive until the contactor is fully energised), but goes to the braking module, before heading to the selector switch, unlike the other two legs that go straight to the selector switch.
The braking module is also connected to the 2nd leg output from the contactor (terminal 4), via the NC contact (R8), so when the contactor is energised, the braking circuit is broken, but once the contactor is de-energised, the braking module is connected to the 2nd and 3rd legs on the motor side. By breaking the 4/R8 link, it should prevent the module from braking (which I'm assuming is done either via DC injection braking, or controlled shorting of the legs).

[OMLCNC]

The readings are what I suspected you'd get, especially with a multimeter.
What about the input voltage to the transformer?
If they also drop, what about the main supply into the machine?


What I can't really make out from the wiring diagram, is are the top right wires, and lower left side wires on the braking module directly connected (I'm guessing each wire has a separate terminal, but are the terminals paired together? - A photo might help)

However, I think if you remove the link between R8 and 4 on the contactor, it'll be enough to break the circuit for the braking.
Do you have a diagram for the selector switch, as it would help understand exactly what's going on?

Assuming the selector switch is just a switch, with no relays/contactors to control things, then the key to the braking circuit is how the 3rd leg is handled. It is controlled via the auxiliary contact (other two legs go via the main contacts, with the third main contact used as the latch for the start button - the start button second contact also bypasses the aux. contact, which I assume also ensures the braking module remain inactive until the contactor is fully energised), but goes to the braking module, before heading to the selector switch, unlike the other two legs that go straight to the selector switch.
The braking module is also connected to the 2nd leg output from the contactor (terminal 4), via the NC contact (R8), so when the contactor is energised, the braking circuit is broken, but once the contactor is de-energised, the braking module is connected to the 2nd and 3rd legs on the motor side. By breaking the 4/R8 link, it should prevent the module from braking (which I'm assuming is done either via DC injection braking, or controlled shorting of the legs).

See pictures - Yes the wires are connected on the PCB board, paired together as you thought, I checked them with "the tester"
Other red wire goes to 24 and brown to R7

Also see pictures of rotary switch, you may be able to work out how it works. It could be the issue if you see my other post to Mr Eddycurrant

[EddyCurrent]

This is the brake unit I think; http://www.klibo.com/brake_16a.html?L=1
and there are drawings etc.

[m_c]

So it is a DC injection brake, in which case disconnecting the link as I suggested will stop the brake from functioning, although I think you'll also want to disconnect the wire going to the Sp terminal on the braking module, as going by the diagram for it, the Sp appears to be some kind of detection signal (it only gets powered when the contactor is active).

However, I still suspect the real problem is the supply voltage sagging with the starting load.
What happens to the main phases powering the control circuit (L2 & 3 on the diagram) when everything is starting?

[OMLCNC]

So it is a DC injection brake, in which case disconnecting the link as I suggested will stop the brake from functioning, although I think you'll also want to disconnect the wire going to the Sp terminal on the braking module, as going by the diagram for it, the Sp appears to be some kind of detection signal (it only gets powered when the contactor is active).

However, I still suspect the real problem is the supply voltage sagging with the starting load.
What happens to the main phases powering the control circuit (L2 & 3 on the diagram) when everything is starting?

I will have a look later.

But why are (1 and 2) and (3 and 4) closed all the time (NO) even if you manually opperate contactor.
ONLY when Planer and Spindle Moulder selected with no power on machine?
When Saw selected they all perform as expected with no power to machine?

[EddyCurrent]

I agree with m_c about which wires to remove, however it may be easier just to pull the connections from C1 and SP at the brake board.(insulate them after diconnecting)
I don't know about the switch enigma but as a starting point you should always check contacts with the wires disconnected to prevent feedback.
If it's okay in the saw position I suggest getting the machine running like that for a start.

Operation of the brake looks like this to me.

If there is voltage or has been voltage at terminal SP (even briefly) and there is a circuit from C1 through the motor winding back to L3 (i.e. contactor has just been de-energised) then brake.
If there is voltage at terminal SP (even briefly) and there is no circuit from C1 through the motor winding back to L3 (i.e. contactor energised) then do not brake.
If there is no voltage at terminal SP (or a brake operation has just completed) and there is a circuit from C1 through the motor winding back to L3 then do not brake.

This also explains why the brake will activate if 'start' is pressed while an e/stop is activated. Start button contact 23/24 apply voltage to SP briefly when pressed but the contactor is de-energised.

[m_c]

There is nothing in the diagram that indicates why the contacts 1 & 2 would show as having continuity, however the other two main contacts could, so it's probably a discrepancy between the diagram and the actual machine.
As Eddy says, you should only be testing for continuity with the wiring removed from the contactor.

[OMLCNC]

However, I still suspect the real problem is the supply voltage sagging with the starting load.
What happens to the main phases powering the control circuit (L2 & 3 on the diagram) when everything is starting?

Disconected brake by pulling off C1 and SP terminals and insulating

So I took multimeter set on Hv put one end in earth and other in L1, L2, L3 in turn. (at the overload 4)
L1 Black wire 330v no load no dip (because the contactors stopped chattering while testing?)
L2 Brown wire 120v no load dips to 75v on start
L3 Grey wire 361v no load dips to 330v on start

While testing on and off and rotating switch for different motors, the chattering contactor problem stoped and I canot get it to do it any more.
There are small sparks from the contactors 5 and 6 on switching on and off.
I dare not touch anything as the problem may return.
What should I do next?
Go back and see if It is still ok, then re-connect the brake?

[EddyCurrent]

Not your standard 3 phase voltages by any means but might be okay for a converter ? I believe there is a minimum load required for one thing but I'm not 100% on that.

I meant to ask this much earlier, was the machine working okay with the current setup, you changed nothing and then the next time you started the machine there was this fault ?

Did you actually start any of the motors during these last tests ? it should be okay to do so but you won't get any braking.

[OMLCNC]

Not your standard 3 phase voltages by any means but might be okay for a converter ? I believe there is a minimum load required for one thing but I'm not 100% on that.

All the information is here to down load https://www.powercapacitors.co.uk/pr...ve-converters/ It states that you can not treat it the same as a normal 3 phase supply.

I meant to ask this much earlier, was the machine working okay with the current setup, you changed nothing and then the next time you started the machine there was this fault ?

Yes, the machine was running for a time then the MCB to the Transwave triped on the saw and the planer, got worse then would not start at all without tripping. Chattery contacts only noticed when opened the enclosure.

Did you actually start any of the motors during these last tests ? it should be okay to do so but you won't get any braking.

Yes ran all of the motors, no braking, but they all started and stopped, many times.

What to do next?