Multico CPT planer thicknesser Wiring diagram.

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merlin

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Does anybody else own a Multico CPT planer thicknesser?
I am having trouble with my newly aquired CPT it is 3 phase and is burning out the contactor coils in the starters.
Can anybody please take a photo of the inside of the starter unit and / or let me have a copy of a wiring diagram as I am trying to make sure it has been wired up correctly.

Thanks, Merlin
 
Hello Merlin,

There are usually two reasons for coils to burn out.
Firstly, if you can, check whether the coils are rated at 240v or 415. If you can remove one, it should have a voltage rating on it. As it is new to you, it may have been run using a neutral before and was bodged for the sale. IE, the neutral connection from the coil just connected onto another phase - usually Line 3/blue phase.
Secondly, are the contactor pole pieces free to move together so that they touch. These are the laminated metal parts that pull into the coil.
They may be jammed with wood dust or rust, if the machine has stood around for a while. If the faces don't meet, the current will increase exponentialy and burn out the coil very quickly.

Regards...Dick.
 
Hello Dick,

The coils are 415volts and the parts seem to move together ok.
I did wonder if it had been neutral connected before so I will contact the previous owner today and try to find out, do any of the link wires get removed or moved about if that is the case?
I am using a 3 phase converter so that makes things a bit more of a pain.

Thanks, Merlin
 
Morning Merlin,

As the coils are 415v rated (can we be clear here, was this rating actually on the coil its self?), they would not have been connected to a neutral.
Coils have a ‘pull in, and a ‘hold in’ voltage. IE. Once in, the power required to hold them in is less.
So 240v would not normally be enough to pull in a 415v coil, but it would probably hold it in once the pole pieces had met.
As I have never worked on woodworking equipment, I can’t comment on specific links. Could you put up a photo of the starter - naked :shock: and does it have a manufacturers name, like MEM or Crabtree for example?

Is the converter part of the machine control, or is it something separate that you had before? It sounds like the latter.

Does the motor run smoothly before the coil burns out, and how long did the coil take to burn out? :cry:

If the machine runs ok, perhaps there is something odd with the waveform that the coil doesn’t like, like insufficient pull in power?

If that is the case, you could wire the control circuit separate from the converter, via the 230v mains that feed the converter (so that isolation isn’t a problem) and buy 230v coils.

To reiterate, coils ‘normally’ only burn out for two reasons, insufficient pull in power, and resistance to movement. Both cause increased current flow which causes the burn out.
I strongly suspect that your coils don’t like the supply from the converter/inverter.

You said ‘starters’ more than one. What functions does the machine have apart from the cutter drive?

If all else fails, you will have to use your wand to ‘magic up’ a money tree to go with your money pit :shock: Sorry I couldn’t resist it any longer. :oops: :wink:

Regards...Dick.
 
It is important when using converters to ensure that the contactor coils are powered from the correct phases.
This should be set out in the manual for the converter.
Transwave - the brand leader - state that contactors need to be powered from L1 and L3 only to avoid what they describe as 'premature ageing' !!
The reason for this is that the L2 voltage can vary wildly whereas l1 and L2 are derived directly from the transfomer and inherently more stable.
If when you re arrange the wiring to achieve this, the motors run the wrong way round, leave L2 connected where it is and simply swap L1 and L3.

Bob
 
Hello Bob,

Thanks for that info. I have never seen the Transwave type of inverter; having been used to full on industrial drives that didn’t suffer this sort of limitation. So at least what I said about the coil being under supplied was right, just the why was in question.
That’s the joy of electrical fault finding. A fair degree of theory is needed, the rest is experience.

Regards...Dick.
 
Dick,

There is a circuit of a Transwave type static converter in figure 24 of my motor paper.

http://homepage.ntlworld.com/bob.minchi ... Issue2.pdf

They are little more than an auto transformer to step up 240 v to 415v giving two phases and a bank of capacitors creating a phantom 3rd phase. The voltage on the phantom phase varies wildly as the motor starts up and can lead to chattering contactors or perhaps at worst, the smoke escaping if this phase is used to power the coils.

Bob
 
Hello Bob,

As the Germans would say ‘alles klar’. You can tell where all our factory machinery came from. :wink:
I used to work for Coca Cola, so it was all line control and water treatment.

I would have killed for the information in your post when I was an apprentice.
My lecturer was a good man, but your layouts and descriptions are excellent. =D>

Regards...DIck.
 
Hello Dick and Bob,

The coils are 415 and marked on the coil itself.

The coverter is a Transwave and is rated upto 4.5 kw (it runs my Wadkin 12" saw etc ok)

The name on the starter is Brook control gear.

The motor runs very well untill it stops or you get a whiff of hot bakerlite! It takes about 10 mins, when the cutter and the roller feed are working it seems to damage both the coils as they are going black.

I want to keep the original switchgear if I can, I spoke to the original owner today and he said that his sockets have 4 wires + Earth in them so I assume that his system used a neutral.
I also got a copy of a wiring diagram from Brook today that says "For line and neutral control - remove link between A1 & 5 on 1C and connect neutral to A1" There is no link between
those terminals on 1C but as per the photo it is fed from the roller contactor (2C). Do I put a link "back in"? would it have 2 feeds?

The L1, L2 and L3 wires from the converter all end up on the 1,2 and 3 terminals on the contactor.

As far as my wand is concerned it has got me into enough trouble over the years so I dont think I had better start waving that about!

Thanks for your help, Merlin
 

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Can you attach some wires to the coils and measure the voltages on them when the cutter motor is running and how it changes when you start the feed motor?

It seems very unusual for both coils to develop similar faults unless it is by external influence and that can only be coil voltage.

Bob
 
Hello Merlin,

I am glad to see that you are retaining your sense of humour in this trying time.

You said that ‘there is no link between those terminals on 1C ...’it is fed from the roller contactor (2C)’.
As the pics are very small, it is not possible to see the terminal numbers, so do you mean that a wire goes from A1 to the roller contactor, or from 5?

Does a wire from the 1C coil go to terminal A1 (it should do) or is it in 5 with the wire that goes to 2C? Or, are both wires in A1? Or are they on their own in each connection? (This should mean that the starter doesn’t energise in the first place)
Next, where does the wire that goes to the roller contactor end up. It should be on L3 at the infeed side (from the Transwave)?

Don’t put the link back in as we don’t know what has been done when the machine was disconnected. Also, it is working...sort of, so the link will probably make no difference.

What I am wondering here is, has the wire that should feed both A1 coil connections somehow been moved to the L2 connection, which as Bob said, is not recommended by the manufacturer. If only you weren’t so far away, I would quite enjoy helping you sort it out.

I get the feeling that Bob is the sort of chap that used to train numpties like me, is that correct Bob?

Regards...Dick.
 
Cegidfa":1dm6gs20 said:
I get the feeling that Bob is the sort of chap that used to train numpties like me, is that correct Bob?

Regards...Dick.


Not really Dick. I did my degree in cybernetics (information theory) and then spent my career in industry undertaking electronics research & development in radio communications and latterly managing those who do such R&D. The only training I have done is to encourage others to think laterally about problems and strive for simply solutions as they tend to work and be reproducible.
I've always been interested in practical things and been dabbling with motors and mechanical engineering since I was a boy. My power electrics knowledge is self taught and has been gained by solving problems for myself and others. Now in retirement (early, through choice) I'm adding wood working knowledge to my armoury from the forums and swapping that for virtually non-stop induction motor advice. I hate brush motors - spawn of the devil to be avoided wherever possible.
That is 40 years summarised in one paragraph!

Bob
 
Hello Bob,

Sorry for the demotion :wink: It is obvious from your writing that we both still share a passion for the humble electron. For a maintenance electrician, as I was, it was rare to find others that still held the inquisitive interest as they got older. I always used to enjoy the challenge of an apprentice, as I believed that there was no such thing as a duff lad, just a bad teacher. It was up to me to find a way of explaining things that made sense to the individual concerned. (But some of them did stretch my creed)

I absolutely agree with you about brush motors, horrible noisy things. Did you ever come across (in the early days) a thing called a Shrage motor. This was a 3ph inverted rotor motor that had slip rings at one end and a commutator at the other. With the speed controlled by a small RQ motor mounted above the comm. and adjusting the brush position - in a dusty bakery of all places. Now that was my idea of hell. :shock:

Regards...Dick.

40 years in one paragraph.....the mother of all redaction.
 
Hello Dick,

There is a wire that goes from 5 on 2C (the roller contactor) over to A1 on 2C then a link wire from there over to A1 on 1C.

The only wire from 1C that goes to the coil is from 33 to A2.

The wires are : 1C.
A1 wire to A1 on 2C.
A2 wire to 33.

2C.
A1 wire from A1 on 1C. Then wire to 5 on 2C.
A2 wire to 33.

I hope this helps, sorry for the lack of know how on the electrical front - I am alright with wood.

Thanks for your help,
Merlin
 
Cegidfa":1d7vrfw0 said:
I absolutely agree with you about brush motors, horrible noisy things. Did you ever come across (in the early days) a thing called a Shrage motor. This was a 3ph inverted rotor motor that had slip rings at one end and a commutator at the other. With the speed controlled by a small RQ motor mounted above the comm. and adjusting the brush position Now that was my idea of hell. :shock:

Ho yus! Back in the 80's when Iraq was supposed to be our friend and we were lending thm pots of money, so on Maggies mates, a bloke called Adrian White could flog them big Water Plants, the Iraquis had got hold of a very old spec for Slip-Ring motors with manual brush lifters and no matter how hard we tried to convince them otherwise, that is what they insised on having for all their Pump drives!

I've also seen the old Shrager drives on pumps, believe it or not in Paper Mills and Asbestos Cement board manufacturing!

I also remember the old Laurence Scott "N.S." drives, you took your life in your hands going into a Pumpstation with those installed due to all the Carbon they chucked out!

We eventually ended up with Frequency Convertors, up to 3kV and 1mW with Phase Shift transformers.
 
Morning Merlin,

Don’t worry about the lack of know how, you are doing alright.
The way that you laid out the connections was very helpful. It has given one part of the information needed.
Now if I can push you a bit further.

Where does the wire connected to A2 on C2 go to?

Where does the wire connected to 5 on C2 go to?

What is connection 33?
Is it the red or blue button at the bottom of the starter? (These are the overload units that protects the motor, and the right hand one acts as the stop button)

Or is it the button operated by the green start button - or something else?

It would be really useful if you could supply the middle two pictures again at four times the size and quality. Especially the drawing, as I can’t see the connection numbers.
Do you have a digital camera, or, can you borrow one - and the connecting lead, to get a higher resolution picture?

Don’t despair, I have the patience if you have the time.

Regards...Dick.

Morning Merlin,

Don’t worry about the lack of know how, you are doing alright.
The way that you laid out the connections was very helpful. It has given one part of the information needed.
Now if I can push you a bit further.

Where does the wire connected to A2 on C2 go to?

Where does the wire connected to 5 on C2 go to?

What is connection 33?
Is it the red or blue button at the bottom of the starter? (These are the overload units that protects the motor, and the right hand one acts as the stop button)

Or is it the button operated by the green start button - or something else?

It would be really useful if you could supply the middle two pictures again at four times the size and quality. Especially the drawing, as I can’t see the connection numbers.
Do you have a digital camera, or, can you borrow one - and the connecting lead, to get a higher resolution picture?

Don’t despair, I have the patience if you have the time.

Regards...Dick.

Hello Tony,

'Fully manual' :shock: - was that an early job creation scheme? Don't tell Mr Cameron. :shock: :)
3kv and 1Mw...ooh er big boys toys :)
 
Hello Dick,

Wire from A2 (on C2) goes to 33.

Wire from 5 (on C2) goes to A1.

33 is the top terminal opperated by the green button.

The picture was taken by digital but had to be resized to go onto the forum.

I tested the voltage today and the results are ;
L1 - L2 - 395
L2 - L3 - 387
L1 - L3 - 423

Accross the coil - 425.


Cheers, Merlin
 
Morning Merlin,

Can you now check where the wire from the other side of 33 on both contactors goes to.
They are probably linked together, but the important part is where they go to in the end.
It should be to the infeed supply, hopefully into L1.

The next check is where the wire goes to from the two linked coil connections (the A1’s)
Probably from 5 on 2C. This should go to L3 on the infeed supply. This will prove that the L2 connection is not being used - as Bob has stated.

As to the voltage, Bob did say that the Transwave is a bit flaky, and whilst a little high is probably ok. What do you think Bob?

Do you run another machine off the Transwave, if there are no problems with with that, then we can assume that the voltages readings are ‘normal’?

The other thing worth checking is that all the connections are tight - but, that isn’t sufficient.
What you need to do is pull every wire, especially where there is more than one in a connection. The control wires that feed the coils may be smaller than the motor supply cables, and when the two meet, sometimes the smaller cable doesn’t get gripped tightly.

I have sent you a pm with my e-mail address so that you can send larger pics and the PDF of the drawing.


Regards...Dick.
 
The L1 - L3 voltage is about right especially as mains voltage can go quite high these days.

Normal figure would be Vin x root 3 so 245v in would give 424 volts out from the transformer

The other two voltages are a bit low as it happens but within acceptable levels so these measurements do not concern me.

hth

Bob
 
Hello Dick,

The wires from 33 on C1 go to 34 then split - one goes to 96 on C2., the other goes to 14 - 13 then over to 34 on C2.

The wires from 33 on C2 go to 34 then over to 13 on C1 - 14 and the 34. (opposite to above)

They do not seem to end up at L1.

The linked connections from A1 end up at 5 on 2C, then via a link wire over to L3.

What do you think about the "line and neutral" thing written under the drawing?

I run a few machines from the Transwave with no problems - Wadkin 12" saw, belt linisher, drill and morticer.

I know what you mean about the clamping of the wires and they all seem ok All I see at the momment is bloody wires!

PM sent.

Cheers, Merlin
 

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