routercnc_MK3

[Clive S]

routercnc

It's a very neat and tidy job you are doing.
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May I ask where you got the three blue connectors (on the din rail next to the relay) from?.
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Can I see a blue wire trapped under the din rail where the connectors are!! ..Clive

[routercnc]

Dean

Thanks for the info. Rushed out into the garage and didn't really see the printing inside the box!

Clive
Thanks for the encouragement!

blue terminal blocks were from ebay
http://m.ebay.co.uk/itm/331547573505?nav=SEARCH
They are really for mains neutrals but work ok like this

Had another look at the picture and it does look like a wire is trapped but it must be a bit of outer sleeving that has dropped into the rail. I was stripping a lot of cables last night.

[JAZZCNC]

ICan I see a blue wire trapped under the din rail where the connectors are!! ..Clive

Bloody hell Clive you must have eaten some carrots as a Kid. Had to look really hard to see that even after you highlighted.

[Clive S]

Bloody hell Clive you must have eaten some carrots as a Kid. Had to look really hard to see that even after you highlighted.

That's what happens when you won't go to bed early.

[routercnc]

Got the 24V relay and the contactor wired in earlier this week. But when I energise the 24V relay, the contactor switches but the MCB for the linear supply then trips out. Tried it twice and it tripped both times.
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Wiring diagram re-posted here:

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Here is a close up picture if it helps:

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The powering up sequence is:
1. Plug in and switch on at wall - this powers up the 24V PSU
2. Switch master on/off switch which puts the system into e-stop mode and lights up the red LED
3. Press the RESET momentary button which switches off the red LED
4. This energises the 24V master relay (which self-latches)
5. The master relay makes a circuit which runs 24V to the contactor A1/A2
6. The contactor switches on (with a click, and the lever indicator on the front moves to I)
7. This takes the mains power from the 6A type D MCB . . .
8. . . . and feeds it to the linear PSU (which is connected to 3 drives), but the MCB immediately trips
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If I disconnect the linear PSU then the relay, MCB and contactor operate and power up correctly and stay on so it would seem that the transformer inrush is too high for the MCB?
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Previously with the linear supply connected to one driver and just through the MCB without the contactor it has switched on (on the one and only time I tried it) without a problem.
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So, what to try? - What is the reason for most of the current draw ? -
Inrush through the 'shorted' coil until the magnetic field is established ? (750VA 2x24)
Charging up the capacitors (40,000uF) ?
Doing the above and powering up the 3off DQ860MA 80V drivers ?
Or some from each ?
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I could try switching on and off several times without any drive connected
I could then try disconnecting the AC supply to the rectifier and see if the MCB stays on with just the inrush through the coil - is that OK to do?
If that is OK I could unsolder one of the capacitors to reduce the charging draw.
Up-spec the MCB ?
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Any ideas? thanks

EDIT:
Bit of reading around and found a document from Allen Bradley, who make lots of good control gear. As I'm protecting the secondary with fuses I can go a bit higher on the primary protection as it is 'just' protecting the wire to the coil and the coil itself. So can probably go to 10A - my logic being:

10A type D should offer around 200A peak for a couple of cycles during switch on
During normal use I'm expecting a couple of amps, so will be OK there
If there is a problem on the primary the 10A MCB should go first as the coil can take 15A and the wall fuse is 13A
Chalon sell the double pole 10A type D for £10.25 all in . . !
Worth a try?

[JAZZCNC]

EDIT:
Bit of reading around and found a document from Allen Bradley, who make lots of good control gear. As I'm protecting the secondary with fuses I can go a bit higher on the primary protection as it is 'just' protecting the wire to the coil and the coil itself. So can probably go to 10A - my logic being:

10A type D should offer around 200A peak for a couple of cycles during switch on
During normal use I'm expecting a couple of amps, so will be OK there
If there is a problem on the primary the 10A MCB should go first as the coil can take 15A and the wall fuse is 13A
Chalon sell the double pole 10A type D for £10.25 all in . . !
Worth a try?

Exactly What I was going to suggest. I think you'll find that you can even get away with 10A Type C. It's worked for me many times before just to get going so try this if you have one.!

[Boyan Silyavski]

Now if you make a soft start for the PSU and i will officially say you are the master of enclosures


http://www.ebay.co.uk/itm/220V-Class...item3f3f435e81

http://electronics-diy.com/soft-star...wer-supply.php

[routercnc]

Silyavski
Wow, wouldn't say I'm the master of enclosures - I'm making most of it up as I go along!

Looked at soft start options but I only found home made circuits so thanks for those links. Hope to get away without them but good to know there is a ready made module should I need it

[routercnc]

Thanks Dean
OK will get my order in with Chalon . . .

[Tom J]

Bloody hell Clive you must have eaten some carrots as a Kid. Had to look really hard to see that even after you highlighted.

I start using spec glasses at 40, try the same Dean:)