Need assistance with electric enclosure please (CSMIO/AC Contactor issue)

Hi guys,

first just a photo of the new enclosure in progress:
Attachment 17258

Sorry I haven't prepared a diagram of my setup but just a quick explanation: main power comes through to disconnect switch and then a simple volt amp meter, then to single pole circuit breaker and then to distribution terminal (black wire is live, blue is neutral and yellow/green is ground)

from there connects are made to two 24v power supplies and again 2 more distribution blocks for the 24v lines, and the other power supply only for CSMIO main power.

after that output 0 of CSMIO connects to the PNOZ safety relay which activates the AC contactor to turn on the big power supply at the top left.

it all works fine except I'm noticing the contactor gets hot quickly and not sure if that is ok or not.

its pole voltage is rated 24VAC, and I'm turning it on by 24VDC, I assumed its ok based on some quick reading but now I dont know.

last read temperature of contactor reached 50C . if it is not suitable or because its cheap quality can you please recommend a good one? to turn on by 24VDC and drive to contactors (one for motors drivers and one for spindle VFD)

this is the one I purchased http://www.amazon.com/gp/product/B00...ilpage_o09_s00


although I'm confident in what I'm doing I'd love some tips and guidance on anything related.

thank you!

You have diagnosed this yourself the contactor will get hot if you run the coil on DC as it is has an AC coil in it. The DC coil will have a higher resistance. So you will have to change it.

Looking good though. Not sure you need two 24V power supplies.

It would be nice to have different colour cables for the DC side of things than the 240V AC stuff.

Simple Change the Contactor to DC type.

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Originally Posted by Clive S

Looking good though. Not sure you need two 24V power supplies.

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Clive the way the Cslabs units works to keep complete isolation the manual advises using separate power supply for I/O. SO that's probably why.?

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Originally Posted by JAZZCNC

Simple Change the Contactor to DC type.




Clive the way the Cslabs units works to keep complete isolation the manual advises using separate power supply for I/O. SO that's probably why.?

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Ok Dean thanks as they say RTFM

Thank you kindly Clive, and Jazz for confirming I'm not an idiot for that setup lol

next issue is connection of safety relay and CSMIO e-stop and HV enable. to anyone familiar with the CSMIO maybe they shed a light on this, I would highly prefer to use the HV_Enable option to start up the contactor and power on the machine. I do this at the moment and is working nicely (aside from contactor issue above) but doing it like this at the moment:

HV Enable -> Safety Relay -> Contactor

safety relay is configured with E-Stop and in the future also with reset button

this works fine but I would also like to have input to the CSMIO that E-Stop was pressed (or generally safety relay disconnected) but with my current setup I can't do that because the HV enable depends on E-Stop input so it's like a racing condition and within milliseconds HV enable turns on and off immediatly due to E-Stop input not up in time ( and never would be of course ) . I feel stupid for trying this.

so is there a possible solution to have both HV_enable and E-stop, controlled by same physical E-Stop button? should I just remove safety relay from HV enable and rely on CSMIO to control the power output of the Spindle and motors? my thought process was in case CSMIO fails to detect E-Stop atleast I have a direct control of power to the main parts of the machine, is this unnecessary?

also note I prefer to use HV enable and will work around that being enabled instead of turning it off.

thanks!

Ok well you can only have one or the other control the Contactor other wise you defeat the point of HVEnable. The point of HV is speed so no point having the Safety relay tell Controller E-stop happened then HV shut down contactor because it's actually longer.

So the Answer is you control Both directly with E-stop using two contacts on the E-stop.
One Contact controls the Master safety Relay which you then use for System Reset and any other things you want to Kill power to like, Vacuum, Coolant etc etc.
Then have the other contact control the E-stop INPUT which then Controls HV OUTPUT and Contactor which turns on Main Drives PSU.

This way you still have Safety Relay in charge of Reset system but with the faster HV in charge of the Drives power. The HV will only turn them ON when Mach is Reset. The system Reset will only turn on Safety Relay when E-stop is clear so the System will re-set and at same time E-stop Input on controller is clear so HV is safe to turn On when Mach is Reset.

Hope this makes sense.!!

Edit: If you want double safety run the HV Output wire thru the Safety relay Contact before going to Contactor. This way if Safety relay fails the PSU will lose power.

Well I won't lie I had to read this 5 times hehehe and still not sure I understand 100% but I got the main idea of two contacts coming out of the E-stop and where you're going.

let me get the chance to try it out and I'll probably post a photo of the setup to verify

as always thanks for sharing your wealth of knowledge Mr. Dean!

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as always thanks for sharing your wealth of knowledge Mr. Dean!

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You mean Mr. Bean:joker:

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Originally Posted by Clive S

You mean Mr. Bean:joker:

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That's bit rich coming from Shrek. . :smiley_simmons:

ops forgot one complication, VFD fault line and drives.

for drives I guess CSMIO supports them independent of estop input. but how can I fit the VFD fault signal into the above setup? if I keep the E-Stop input as active high then again same issue of cycle between HV and EStop since the fault line of VFD will power up after HV is enabled only.

instead if I use active low setup and normally open connection of the VFD and E-Stop button and all, that would solve it I guess but is that acceptable risk? to have no signal as an indication of things are ok at E-Stop input?

the reason I want this is because I think its important that if VFD/spindle runs into trouble the drives stop also. it happend to me once with overcurrent error and luckily I was just using MDI so I would like to use the safety features of the VFD.

thanks!

Use a separate Relay and have the VFD fault Signal turn it on when goes active. Run the E-stop signal thru NO contact.

new small issue/confirmation : regarding ground, it is best to have one point for all ground right? meaning if chassis of one device is grounded and the whole sheet is grounded, I should not wire the ground connections of other devices if they also ground their chassis right?

illustration:
Attachment 17269Attachment 17270
in first photo you can see I have connected the power supply chassis to ground wire which goes back to main ground point ( distribution terminals ) so the whole back is grounded. in second photo VFD and power line filter have earth connections but by checking continuity test already these points are connected to back also. so should I skip connecting ground wire to them?

thank you!

after some research I realized that all ground contacts should be connected and not rely back panel, anyway I need confirmation of another issue please

when connecting the VFD with contactor, should all wires ( L,N,Gnd) be connected through the poles or can I just connect the Live with contactor and rest direct from mains power?

what about the DC output power supply for the drivers?

thanks!

Quote:

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Originally Posted by Noplace

after some research I realized that all ground contacts should be connected and not rely back panel, anyway I need confirmation of another issue please

when connecting the VFD with contactor, should all wires ( L,N,Gnd) be connected through the poles or can I just connect the Live with contactor and rest direct from mains power?

what about the DC output power supply for the drivers?

thanks!

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If you really want to connect the VFD through the contactor then just the live would be fine (and not the N or E), but having said that I suppose it depends on the power system to your building as it may be different than the UK.


I personally would not connect the mains VFD through the contactor but would just connect the signal wire to make it stop.

The DC output from the power supply should not go through the contactor either .

Perhaps you should find somebody local to give you some help with this before you get a chance to damage it all or yourself.

Quote:

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Originally Posted by Clive S

If you really want to connect the VFD through the contactor then just the live would be fine (and not the N or E), but having said that I suppose it depends on the power system to your building as it may be different than the UK.


I personally would not connect the mains VFD through the contactor but would just connect the signal wire to make it stop.

The DC output from the power supply should not go through the contactor either .

Perhaps you should find somebody local to give you some help with this before you get a chance to damage it all or yourself.

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hmm well I seem to remember reading that it's safest to turn off power instead of just relying on signal coming out of the devices(drivers,VFDs)
and the examples in the CSMIO show it this way.

also I would like to you utilise the software to enable a power on signal

If you still want to include a contactor to the VFD, then I'm pretty sure that if you hit the e-stop (and turn off the mains power to the VFD) it will not like having the spindle spool down and feeding power back into it when it is not on. Would it damage it? Not sure. But I wouldn't risk it myself.

I see in one of your earlier posts that you have a braking resistor, which can allow quicker ramp downs (although I've not used mine as it is plenty quick enough without). If you plan to use it I would imagine that killing the power to the VFD would not allow it to use the resistor and it would coast down over a much longer period.

So if you still want to do this I think you would need a delayed timer on the contactor to switch it off after say 5 seconds, depending on your ramp down parameters. This adds complication, but I know Dean has done this so it is possible. This is in addition to the e-stop logic signal telling the VFD to stop, which you would do first to stop the spindle safely under VFD control.




I seem to remember reading some time ago that you can be specific and tell the VFD that this is an emergency (not just a regular stop / start command) and it will do an emergency ramp down / stop which is quicker.

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Originally Posted by Noplace

also I would like to you utilise the software to enable a power on signal

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If your refereing to HV enable then it's not really very suited to this application because it will Kill power to VFD every time you put Mach in reset. Which will be often. This constant stop starting isn't good for the Vfd and will damage it over time.
Also you won't be able to start cutting straight away after a reset and will need to wait for VFD to power up fully which could be pain.

If you really do want the VFD turned off then I would have the VFD tied to E-stop but keep it separate from HV enable. Just have HV enable control the drives PSU and the Spindle RUN Command.
This way when Mach3 is in Reset mode then the VFD stays on but can't started until mach is reset. At which point HV enable turns on the drives and allows spindle RUN signal to reach VFD when needed.

Think of it has two separate systems working together. E-stop is hardwired and kills everything, HV enable just kills Drives and Run etc but only when mach is in Reset.
There are many times you'll want some things powered while Mach is in Reset mode. Ie Vacume but at same time your not in E-stop condition.

thank you guys for the insight and preventing me from making a mistake, I guess the VFD manual confused me because it has some notes about when using a contactor. so in this case is there use for a contactor (for the VFD) at all if controlled through a constant turn on signal?

appreciate your input on following related subject as well: at the moment the planned way to start/stop the spindle is through input signal coming from CSMIO (the usual way) , in case of problems and I hit E-Stop, naturally CSMIO will disconnect that signal and spindle will stop normally.

is that sufficient or should I utilise the other input ports of my VFD, it has a total of 8 ports to accept commands from a controller.

they are as following:
0 - No Effect
1 - first multi speed ( references a table in the manual )
2 - second multi speed ( references a table in the manual )
3 - third multi speed ( references a table in the manual )
4 - frequency rises
5 - frequency decreases
6 - forward jog
7 - reverse jog
8 - forward ( this is what I used before and works fine and is enough to start/stop it )
9 - reversal
10 - forward trigger
11 - reverse trigger
12 - stop
13 - freely shutdown
14 - forced shutdown
15 - forced inversal
16 - counter is cleared
17 - counter input
18 - program run reset
19 - external fault
20 - external reset
21 - accelerate and decelerate - time choosing first ( references a table in the manual )
22 - accelerate and decelerate - time choosing second ( references a table in the manual )
23 - accelerate and decelerate pause
24 - force ACI passage effective


I don't understand most of them but its a direct copy-paste from the manual.

so is it worth doing a setup where one of those functions is triggered during E-Stop? maybe the stop or external fault? hehe feels like overthinking things

Quote:

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Originally Posted by Clive S

Looking good though. Not sure you need two 24V power supplies.

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The CSLabs documentation says "If you use in the system such inductive loads as electromagnets, solenoids, electromagnetic clutches – it is recommended to use separate 24V power supply for the mentioned receivers and separate for CSMIO / IP-S."

This to me suggests that you only need one power supply if you are just switching small loads, such as relays, and a decent size capacitor across the power inputs would remove any ripple, which might cause problems.

I do not intend to go the extra expense of a second power supply unless absolutely needed.

Cheers,

Rob