Control Schematic Advice

[GTJim]

I’m here lookingfor help again and hoping you may be able to spare some time to review my schematic,as I am going around in circles and confusing myself.

I have tried tobreak down the schematic into sub-systems that simplifies it.

Page 1 –Covers the VFD, spindle control, breakout board and ESS.

Page 2 – Thepower supplies for the various boards, drives and VFD.

Page 3 – Relays,Option 1, in this I proposes the use of 4PDT 24Vdc 10A relays for the mainsafety relays (K1, K2 & K3), limit switches, home switches and touch probe.

Page 4 – Relays,Option 2, this is my failed attempt of incorporate a couple of PILZ relays Ihave, but got stuck with the wiring. I wanted to use a PNOZ X7 (774059) as K2and either PNOZ X9P (777609) or PZE 9 (774150) as K1. Not even sure it’spossible.

Page 5 – Stepperdrives and motors.

I have beenlooking at this for some time and need further advice as the components havechanged to include spindle control, ESS, etc.

I've read otherposts on MYCNC regarding control panels but the selection of the various componentssuch as suitable MCBs, home & limit switches, earthing, etc isconfusing due to the number and variation available.

Any adviseor guidance will be welcome.

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Not sure why the pdf's are showing up as black boxes but they seem to open?

Jim

[JAZZCNC]

Shit forgot to reply to your email Jim Sorry I will now. Or better still email me your number and I'll give you a ring as it much easier over the phone.

[m_c]

I've not looked in great detail but the following stand out to me-
Home switches should be wired NC if you're looping them together.
.
Do you really need to use two seperate relays for limits and E-stops?
I know it can be nice to know what's just caused everything to grind to a halt, but it does add cost and complexity for little practical benefit when you could simply wire the limit swithced in series with the e-stops. And if you're unsure what's caused things to stop, hitting the limit overide should tell you if it's a limit or e-stop issue.

[JAZZCNC]

I've not looked in great detail but the following stand out to me-
Home switches should be wired NC if you're looping them together.

They are NC switches but there's a bigger problem here.? The A2 on K1 relay doesn't go to 0V it goes to 15-70V on the BOB so it won't ever turn on.!

Also don't kill power to the BOB leave it running.

Ring me Jim.

[m_c]

They are NC switches
I know they are, but they're shown wired NO in the diagram...
Unless Jim is planning on them only being activated when in the home position, then it's wrong.
.
Good catch on the BOB power. You really don't want to kill that.

[JAZZCNC]

I know they are, but they're shown wired NO in the diagram...
Unless Jim is planning on them only being activated when in the home position, then it's wrong.

Erm ye go on then I'll let you have it on technical merit. .:hysterical: . . . . But I think it's just that Jim found the first symbol of a switch to use and thats why he wrote NC so we'd know which switch type.?

[m_c]

You ain't getting nothing on technical merit!
.
He's got COM, NC, and NO shown, but has used the COM & NO in the diagram.

[JAZZCNC]

You ain't getting nothing on technical merit!
.
He's got COM, NC, and NO shown, but has used the COM & NO in the diagram.

Sorry MR my mistake didn't notice you said Home switches I was looking at Limit switches. Obvioulsy your correct and I'll go sit in the naughty corner. .Lol

[m_c]

:highly_amused:

11732

[JAZZCNC]

:highly_amused:

11732

Yes Moray that's quite fitting to me this last week has lack of sleep along with diminishing eye sight have made for some Dunce moments.!! . . . . I may just make a sign like that for the door. . Lol

[EddyCurrent]

Can you get anything useful from here ? I'm also using PILZ and ESS
http://www.mycncuk.com/forums/gantry-router-build-logs/6565-ready-steady-eddy-9.html#post52213

[JAZZCNC]

Can you get anything useful from here ? I'm also using PILZ and ESS
http://www.mycncuk.com/forums/gantry-router-build-logs/6565-ready-steady-eddy-9.html#post52213

Ye how to go completely OTT with building a DIY control Box. . :hysterical:. . . (Chill before throwing chisels at me I'm only playing with you, each to there own.!)

[GTJim]

Cheers for the comments the switches were ment to be normally closed and are shown wrong. Lol
Im out at the moment and will get back when I'm home.
The pilz relays were only me trying to make use of stuff ive already got and may be beter than some cheap alternatives.

[EddyCurrent]

As has been said, put the limits and E/Stops in series. don't cut power to the bob.
You would then just need to use the PNOZ X9P, also why are you have a reverse option on the VFD ?

[GTJim]

I may be wrong but I only wanted the limits to kill the steppers and leave power to all the other systems and the estop to kill everything but the supply to the bob.

[EddyCurrent]

I may be wrong but I only wanted the limits to kill the steppers and leave power to all the other systems and the estop to kill everything but the supply to the bob.

There is no right and wrong, that's a fair requirement. I chose to put the limits and E/Stops in series because I couldn't see the point of having both scenarios you mention, what's the point of killing power to the steppers but leaving the VFD running for example ? You can still put the limit override switch across them if they are in series with the E/Stops.

[GTJim]

It seems like a few amendments are needed.
Has anyone got an easy to understand grounding/earthing diagram for a similar circuit, and info regarding suitable components to use?
Below is a very basic sketch I've found but not enough detail.

[Clive S]

It seems like a few amendments are needed.
Has anyone got an easy to understand grounding/earthing diagram for a similar circuit, and info regarding suitable components to use?
Below is a very basic sketch I've found but not enough detail.
Just my 2 cents worth. Personally I would not put the VFD inside the control box as it will generate a lot of noise (rf speaking). Also it's not a good idea to daisy chain the power supply to the drives, I would run separate cables back from each drive to the power supply. The grounding of all the screens on the cy cables etc should all go back to one central place, (called a star) Most people tend to ground the screen at one end only.. ..Clive

[GTJim]

Hi Clive, thanks for your comments.
I was only using the sketch to show a very simple example of grounding/earthing and was hoping to get feed back relating to methods and components used.
Jim

[EddyCurrent]

As Clive says each driver should be wired back to the PSU.
For my earth star point I'm using the terminals DIN rail. If you use these for your screens, EK2.5 - Detailed item view - Chalon Components (http://www.chaloncomponents.co.uk/shop/article_EK2.5/EK2.5.html?sessid=4MKbBNy77nNfvi9yhtJ6jbpgTzKH65Ad Yd29GZ0k0LaAtO8RWGv7ZHeJpVZH7E6k&shop_param=cid%3D134%26aid%3DEK2.5%26), they earth right onto the rail which becomes the star point and it's tidy.

Also have a read at this (though for some reason I always seem to get some stick for these posts)
http://www.mycncuk.com/forums/routers-spindles-controllers/6945-router-has-died-need-advise-please-5.html#post53732

[GTJim]

First of all a big thanks for all the input, it has probably saved me from making many fu*k-ups.
The redesign has now been simplified and is based around the PILZ PNOZ X9P relay and the highly regarded PMDX-126 board.
This seems to have simplified the design as all the individual relays that needed to be hooked up together have been discarded. It has also provides additional features that may be useful such as machine hold.
While individual components have increased in price, I believe the reduced the part count will compensate for this and the final cost will hopefully be in the same ballpark.
I have attached pdf’s of the revised schematics for further comments, before I start digging down into the detail.
Jim

[EddyCurrent]

Nice drawings Jim, here's what I see;

1. Pin 6 of PMDX-107 should go to VFD ACN (ACM ?) (GRD) terminal.
2. Why is there a switch in the PILZ terminal A1 supply ? it's not normal.
3. Can the PILZ relay contacts handle the VFD supply current ?
4. Can the PILZ relay contacts handle the 70V PSU input current ?

[JAZZCNC]

2. Why is there a switch in the PILZ terminal A1 supply ? it's not normal.

Well that depends doesn't it.? . . . . It's normal for me.!!

I often put control panels on the front of the machines and having this cut power to relay is a bit of safety so the relay can't power up when changing tools etc. 24V is Safer than running high voltage into machine and messing around turning main cabinet supply off.

[GTJim]

Nice drawings Jim, here's what I see;

1. Pin 6 of PMDX-107 should go to VFD ACN (ACM ?) (GRD) terminal.
2. Why is there a switch in the PILZ terminal A1 supply ? it's not normal.
3. Can the PILZ relay contacts handle the VFD supply current ?
4. Can the PILZ relay contacts handle the 70V PSU input current ?

Hi Eddy,
1. I have gone through manual and agree so I have amended the design.
2. Well Dean has responded to this, so I guess its a matter of personal choice.
3 & 4. Now this is getting a bit deep for me, but if I am reading the Pilz documentation correct the safety contacts can handle 240VAC and 8 amps, but I stand to be corrected.

Thanks for your help
Jim

[EddyCurrent]

Well that depends doesn't it.? . . . . It's normal for me.!!

I often put control panels on the front of the machines and having this cut power to relay is a bit of safety so the relay can't power up when changing tools etc. 24V is Safer than running high voltage into machine and messing around turning main cabinet supply off.

I'm not going there, do what you want, what I'll say is, it's not normal for the numerous industrial installations I've seen. 'Isolation and immobilisation' is a subject in itself.


Hi Eddy,
3 & 4. Now this is getting a bit deep for me, but if I am reading the Pilz documentation correct the safety contacts can handle 240VAC and 8 amps, but I stand to be corrected.
Thanks for your help
Jim

If the PILZ document says that and the VFD and PSU take less current then it sounds fine, the only issue I'd think about is the inductance of the 70v PSU transformer when the contacts open. This is why I used a separate contactor because it's cheaper to replace a worn out contactor than it is to replace the PILZ relay. Having said that I've just looked at your drawing and I can see the load is split over 4 separate contacts in the PILZ (2 in series then those in parallel with another 2 in series) so that might be okay provided they all open at the same time otherwise the first one to open gets to break the arc.

[GTJim]

I have included a soft start on the 70V power supply to control the inrush current so this should prevent any issues, shouldn't it?

[EddyCurrent]

I have included a soft start on the 70V power supply to control the inrush current so this should prevent any issues, shouldn't it?

It will for switching ON but I'm talking about switching OFF

Read on page 1 under "Inductive Load"

http://www.nkkswitches.com/pdf/electricalratings.pdf

It's not so bad that we are talking about AC where the voltage crosses zero at 50Hz so it helps extinguish the arc, unlike DC. I've had 'belts' off both and I can tell you it's easier to let go of AC than DC

[firetrappe]

Jim, that's a very nice schematic you've drawn.

I've just been studying it as you're using very similar components to my panel.

As you're using the second parallel port anyway (M-Hold on K input), it might be worth considering using the 'H' input on J11 for your touch plate rather then pin 9 on J12.

If at a later date you decide to add a digitising probe then you can use pin 9 on J12 for that and enable the 'probe merged inputs mode' on the PMDX-126.

No big deal, just something i've done as I can see myself adding a touch probe at some point.

Si.

[JAZZCNC]

I'm not going there, do what you want, what I'll say is, it's not normal for the numerous industrial installations I've seen. 'Isolation and immobilisation' is a subject in itself.

But that's just it Eddycurrent where not in industrial application we are DIY application and your just creating worries for people when they need not worrie.!!

I've had a second hand pilz relay on my machine for 3yrs now along with the On/Off switch inline with 24V switching 75v without any issues and before coming to me I'm pretty sure it had done plenty of work so I'm sure it will be fine Jim.

[GTJim]

Thanks for all the comments and suggestions.
I find this subject dificult as I'm more mechanical biased but have enjoyed the challange.
I'll make Si's amendment to the schematic and lets hope its somewhere near so I can look at the detail as thats bothering me.
More questions to come. Lol
Jim

[GTJim]

Now fuses and MCB’s, where and which?

Although I have these scattered around on the schematic it would be useful to know exactly where they are required and how to calculate the correct size.

I’ll start a list and if you can help complete it please let me know.

Position - Fuse/MCB - Size
Mains inlet – Fuse - 13A
Supply to VFD -
Supply to 70V Power Supply -
Supply to 24V Power Supply -
70V supply to Motors -
Supply to PMDX-126 -
Contacts R and S on VFD -
Supply to coolant pump -

[JAZZCNC]

Jim, that's a very nice schematic you've drawn.

I've just been studying it as you're using very similar components to my panel.

Ah ah that'll be because I recommended same to Jim as I did you Si.!! . . . . I even sent him the diagram I did for you with pretty pictures on it. . .Lol

[GTJim]

Dean you brought me back from the dark side, lol.
Keep it simple is always the best way.

[firetrappe]

Yup Dean, you know how I like pretty pictures. It's more complicated to draw but really helps me get my head around how things work. Without your help Jim's schematic would have baffled me, thankfully I actually understand it now. And it's only taken me 6 months of reading build logs and countless hours on the phone you you lol. Cheers bud :)

Jim, i've attached a version of my 'schematic' below. I use corelDraw daily at work, so the easiest way for me to plan my wiring and layout was to draw it like this. It looks messy and complicated in the PDF, but it's all drawn using 'layers' so I can switch off/hide individual circuits when i'm working from it.

I've got a few tweaks to make to my wiring yet. Later on this weekend i'll upload the final layout and a photo of my completed panel for comparison.

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Thanks needs to go to Dean(JazzCNC), Thomas (Eddycurrent) and Graham (Wobblycogs) for their advice and build logs which helped me get this far!

Si.

ps. Jim if you haven't seen Grahams website with his detailed build log yet (similar components used again) then have a look here : Yeti (http://www.cnctrl.com/index.php/builds/yeti?start=10)

[EddyCurrent]

Because you are supplying the VFD and 70v PSU via the PILZ relay make sure you put the fuses for them before the PILZ, that way they will also protect the PILZ relay contacts if the fuses are less than 8amps. If the fuses are greater then 8amps then if there is a fault it could wipe out the PILZ contacts as you said they were rated at 8amps max.


Jim, i've attached a version of my 'schematic' below.
Strictly speaking that's a 'wiring diagram' but let's not worry about that, it's a good idea using layers, Inkscape would be a free alternative to Corel Draw.

[firetrappe]

As promised earlier here's a photo of my panel and updated wiring diagram.

I've maintained the layers in the PDF. If you open it with Acrobat Reader 6.0 or later and go to View > Show/Hide > Navigation Panes > Layers, then you can turn the layers on/off by clicking on the 'eye' icons next to the layers.

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The panel looks quite neat with the covers on the trunking, I left them off for the photo so more of the wiring can be seen.

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Hope these help someone at some point.

Si.

[JAZZCNC]

Si what are those in the door.? They look like Switches.? but what are they controlling.?

[GTJim]

Si that looks very good and if i can get mine laid out as well I'd be happy.
Do you have any fans in the cabinet and are they needed?

[GTJim]

Where did get the terminals and isolation switch?

[firetrappe]

Si what are those in the door.? They look like Switches.? but what are they controlling.?

Dean, they're just LED lamp holders. One as a 'ac power on' indicator (so I don't forget to switch it off!), the other connected across the NC terminals of the contactor to show when it's not latched on.


Si that looks very good and if i can get mine laid out as well I'd be happy.
Do you have any fans in the cabinet and are they needed?

Thanks Jim. There are 2x 24v fans in the cabinet. One can be seen just below the BOB pulling air in, the other is at the top in the middle pulling air out. I could have got away with just a vent at the top, but as I had 2 fans and a load of filters I thought i'd use them.

The Din rail terminals are these : EK2.5 - Detailed item view - Chalon Components (http://www.chaloncomponents.co.uk/shop/article_EK2.5/EK2.5.html?sessid=MomLjwEvYyzWPpnoEIMwWqA8vXRdmhlf CimE22ZnQyMvEuDrce9voJAXBk3ppI1m&shop_param=cid%3D134%26aid%3DEK2.5%26) and these : JXB2.5 - Detailed item view - Chalon Components (http://www.chaloncomponents.co.uk/shop/article_JXB2.5/JXB2.5.html?sessid=MomLjwEvYyzWPpnoEIMwWqA8vXRdmhl fCimE22ZnQyMvEuDrce9voJAXBk3ppI1m&shop_param=cid%3D135%26aid%3DJXB2.5%26)

The isolator switch is this one : Buy Non-Fused Switch Disconnectors 32A 3P Door Interlocked RS LBDI323P online from RS for next day delivery. (http://uk.rs-online.com/web/p/non-fused-switch-disconnectors/0466176/)

[JAZZCNC]

Dean, they're just LED lamp holders. One as a 'ac power on' indicator (so I don't forget to switch it off!), the other connected across the NC terminals of the contactor to show when it's not latched on.

Ah ok for a mo I thought you'd put Reset button and stuff in door instead of on machine and trying to send me bonkers. . .Lol

[EddyCurrent]

Fastlec are sometimes okay, compare prices.

Industrial Automation & Control Systems - Fastlec.co.uk (http://www.fastlec.co.uk/control-and-automation-c-1807.html)

[JAZZCNC]

Fastlec are sometimes okay, compare prices.

Industrial Automation & Control Systems - Fastlec.co.uk (http://www.fastlec.co.uk/control-and-automation-c-1807.html)

You joking they are nearly twice the price for Din terminals.!!

[EddyCurrent]

That's why I said compare prices, some things a dearer some are okay.

[EddyCurrent]

I could have got away with just a vent at the top, but as I had 2 fans and a load of filters I thought i'd use them.

Have you been using the machine then and got a feel for the kind of temperatures reached in the panel ? I was hoping to use just a vent on top myself with 2 fans sucking in via filters.

[firetrappe]

Ah ok for a mo I thought you'd put Reset button and stuff in door instead of on machine and trying to send me bonkers. . .Lol

Lol, no mate. 24v on/off switch, reset, e-stop, limit override and feedhold buttons should all be on the machine control panel.
I added a lamp on the contactor as I've been caught out a few times at work when e-stop buttons have accidently been pressed while a machine was powered off. Then i've gone round checking guards and fuses before i've realised why there was no life in the machine when I switched it on :/


Have you been using the machine then and got a feel for the kind of temperatures reached in the panel ? I was hoping to use just a vent on top myself with 2 fans sucking in via filters.

A bit like you I've been working on the control panel before the machine. I've no idea what the temps will be inside the panel during use. I didn't really have space for both fans on the bottom gland plate. I figured the one at the top should help evacuate warm air from the drivers' heatsinks, hopefully it will also prevent dust settling on top of the vent/filter during use too.

[EddyCurrent]

Ah ok for a mo I thought you'd put Reset button and stuff in door instead of on machine and trying to send me bonkers. . .Lol

The reason I put mine on the door was because it's wall mounted and right next to the machine, I got a wireless MPG pendant that I'll be using most times.

[JAZZCNC]

The reason I put mine on the door was because it's wall mounted and right next to the machine, I got a wireless MPG pendant that I'll be using most times.

Ah ye your probably wondering why it might send me bonkers.?. . Lol . . . I'm building the machine for Si and we are putting Switches, Reset and E-stop, feedhold etc in control panel on front of machine so when I saw what looked like switches in door I thought we'd got ( Get ready for the Pun.!!) . . Crossed wires . . Lol

[assadi]

Hello,
I'm new to CNC machine, I need your help. I have difficult in understanding the limit switch and the homing switch. I prefer to seprate the homing from limiting, i have 6 limit switch and 6 inductive proximity switch, I was planning to use the 6 limit switch for limiting (2 on each axis) and use 3 of the 6 inductive switch (one on each axis) and one inductive on x' axis for auto squaring (dual drive x axis), my problem is where to connect the limit & inductive switch on the Pmdx-126 ?! On which port?! Does I need relay ?!
Appreciate your help.
Murad

[ngundtoft]

Hi GTJim. I have been looking at the very nice wiring diagrams you have made for your router. I have actually based my diagrams on your drawings, since we have very similar setups, and I did not know so much about safety relays.
I noticed that you use a separate time delay relay for the power supply (1 to 10s). But this is not really required. The Pilz PNOZ X9 safety relay has an on-delay of approx. 200ms (manual reset) which is fine for this use. 1 to 10 s is way too long time and only results in heating up the resistor.