Schneider ZBE 101 is not working

[LordKelvin]

Hi guys,

I would to say hello to everyone and hope I will be comfortable in this forum!!

I am a mechanical engineer and I am in a certain way "forced" to learn also electrical stuffs.

At the moment I am trying to understand why my RESET button (ZBE 101) on my machine does not work.

I narrowed the issue on the loop that has to change the state of the security relay PILZ PNOZ X2.8P
I mean if this circuit is "closed" then the PILZ switches all the NO contact and energise other three safety contactors (and from there I will have the option to start the machine etc. etc.)

In order to close the loop as you can see from the picture attached we need to go through the block A that is actually a series of interlocks and emergency buttons (I already checked them: the interlocks have "green led" that means they are working so NC; the emergency button are released so NC)
and
through the block B where I assume is the problem.

The block B is a series of 3 safety contactors connected by their NC connections (so they are all three NC contacts in the loop) and (always in series) with the RESET button that is instead NORMALLY OPEN.

As you will understand, the ONLY NO contact is the reset button (Schneider ZBE 101) so I push the reset button, I close the loop and the PLZ should switch its state!

My problem is that when I push the reset button, The ES does not switch. I have the power led (due to the red line in the picture) but the other two leds (CH1 and CH2) are OFF,


Any advice, input etc. will be really appreciate.

It looks simple the way it works but actually I am stuck at the moment. Thanks.


FURTHER INFO: I had to take off all the wires and rewire again, but I checked all the connections in the loop and they are the same of when the button was working.

 

[Bobster]

Power down the panel, and measure continuity across the push button when it's pressed.

 

[Darkwood]

The issue with safety relays is there are many out there that all work and connect differently to comply with differing circuit arrangements and safety cat' .. your drawing means nothing without terminal ID and a possible link to the wiring plans for the unit you have with the wiring option that is been used....

Please add the terminal ID's so at least we can cross reference what you have done?
Do you have a meter to confirm Closed circuits on the E-Stops and limits and also to confirm N/O to closed on the reset?

Lastly I hope you are aware of the implication and weight of responsibility you have put on your shoulders here getting involved with machinery safety equipment, from what you describe you are probably not insured or covered to do so and you seem to be picking it up as you go along where you main career is Mechanical Engineer... who is forcing you because what you are doing could in a worse case scenario get someone injured or killed if the system failed to function properly after you had been involved, you are stepping into a quagmire of legal issues here because you feeled pressured to sort it out. Stick to what you know where I'm sure that you are more than competent and always get an Electrical Engineer in for these matters. That way all correct procedures will have been followed, all parties will be covered to do and insured and the correct paperwork issued... anything goes wrong then and the paper trail will save your ---.

 

[LordKelvin]

The issue with safety relays is there are many out there that all work and connect differently to comply with differing circuit arrangements and safety cat' .. your drawing means nothing without terminal ID and a possible link to the wiring plans for the unit you have with the wiring option that is been used....

Please add the terminal ID's so at least we can cross reference what you have done?
Do you have a meter to confirm Closed circuits on the E-Stops and limits and also to confirm N/O to closed on the reset?

Lastly I hope you are aware of the implication and weight of responsibility you have put on your shoulders here getting involved with machinery safety equipment, from what you describe you are probably not insured or covered to do so and you seem to be picking it up as you go along where you main career is Mechanical Engineer... who is forcing you because what you are doing could in a worse case scenario get someone injured or killed if the system failed to function properly after you had been involved, you are stepping into a quagmire of legal issues here because you feeled pressured to sort it out. Stick to what you know where I'm sure that you are more than competent and always get an Electrical Engineer in for these matters. That way all correct procedures will have been followed, all parties will be covered to do and insured and the correct paperwork issued... anything goes wrong then and the paper trail will save your ---.

We have a company that certifies everything and think about safety certifications etc. CE marking etc. I am just learning about this because I will need to understand better the machines for my training on machinery. So I do not believe there will be any issue for me, isn`it?

I will check what asked

 

[LordKelvin]

Noone is forcing me, it was under " " :cool3:

 

[LordKelvin]

The issue with safety relays is there are many out there that all work and connect differently to comply with differing circuit arrangements and safety cat' .. your drawing means nothing without terminal ID and a possible link to the wiring plans for the unit you have with the wiring option that is been used....

Please add the terminal ID's so at least we can cross reference what you have done?
Do you have a meter to confirm Closed circuits on the E-Stops and limits and also to confirm N/O to closed on the reset?

Lastly I hope you are aware of the implication and weight of responsibility you have put on your shoulders here getting involved with machinery safety equipment, from what you describe you are probably not insured or covered to do so and you seem to be picking it up as you go along where you main career is Mechanical Engineer... who is forcing you because what you are doing could in a worse case scenario get someone injured or killed if the system failed to function properly after you had been involved, you are stepping into a quagmire of legal issues here because you feeled pressured to sort it out. Stick to what you know where I'm sure that you are more than competent and always get an Electrical Engineer in for these matters. That way all correct procedures will have been followed, all parties will be covered to do and insured and the correct paperwork issued... anything goes wrong then and the paper trail will save your ---.

It is a demonstration machine that it is being used for my training. My background is automation and robotics in Uni. I will in the Machinery department and I am having under supervision a training on it. So I do not think I will have legal issues with this. Am I wrong?

Btw I could ask for some external training or course if you do not mind I might write to you in pm. So I dont go OT here. Really appreciated.

 

[Darkwood]

Cheers for the explanation ..the fear was you were out on site trying to repair a machines critical safety system by asking a forum ...you can understand my hesitation to go any deeper without making it clear where you may have stood.... if this is just a test rig for personal training and not out in the field then a different matter altogether and would have helped a little to know in your opening post.
http://www.is-com.ru/files/PNOZ_X2_8P_en.pdf
Right then the wiring plan is here ^^^, you can easily check if you have a faulty start button contact block or broken wire by momenterally putting a link between terminals S12 and S34, if the relay resets then the problem is in your reset loop.


If it doesn't reset then your issues may be elsewhere and again you can prove it quite simply by removing wires and fitting links on the loop inputs to prove you have no open circuits on the loop you disconnected or simply use a meter to check your loops are closed.

Cannot tell you anymore without knowing which of the systems on page 3 of the link you have.

 

[LordKelvin]

Thanks to everyone for all the replies. I will do tomorrow at work, having the machine there for me. As you will understand I am still learning about the subject and I already downloaded that document and I will provide tomorrow all the answers. thanks a lot guys!!!

 

[Darkwood]

Welcome to the Forum anyway I'm sure your PLC programming and automation knowledge will be helpful to others ...(If I'm having a day off ) feel free to press the like and thanks button to boost our tally ... we get a free mug at 1000 thanks ; not really!

 

[Chrishands]

Hi mate, not sure what you know about these Pilz units but usually you have a dual safety circuit. And a reset circuit. There is usually 5 lights. 2 lights for each chanel on your safety circuit, both these lights should be on, if so, both channels will be made. You can then push reset which should send a low voltage back to the Pilz and providing all your required chanels are closed circuit (healthy) then the pilz contactor should pull in and your 2 output lights will come on aswell as your 2 chanel lights. When you press your reset button usually it also flags a light up o the pilz to let you know its fecievi g it.


check you havent got your chanels crossed. S11 to s12 and s21 to s22

 

[LordKelvin]

Hi mate, not sure what you know about these Pilz units but usually you have a dual safety circuit. And a reset circuit. There is usually 5 lights. 2 lights for each chanel on your safety circuit, both these lights should be on, if so, both channels will be made. You can then push reset which should send a low voltage back to the Pilz and providing all your required chanels are closed circuit (healthy) then the pilz contactor should pull in and your 2 output lights will come on aswell as your 2 chanel lights. When you press your reset button usually it also flags a light up o the pilz to let you know its fecievi g it.


check you havent got your chanels crossed. S11 to s12 and s21 to s22

I noticed only three leds. Power ch1 ch2. Atm power only is ON. I know the basic theory. I tried to sort out on my own before posting..also because it is part of my learning process to get into the subject with my effort

When today I ll have my machine I ll try everything suggested here atm and I ll tell everyone whats going on. If I will still able to write...zZz zZz...joke! Well..not really (((

I m always super careful anyway

 

[LordKelvin]

http://s11.postimg.org/xdef4gnjn/SR_scheme.png

the updated scheme with more info. If any news you can add thanks

 

[Bobster]

Looks ok, quickest solution is to power the panel down, then just go point to point with a continuity meter to prove everything is as it is on the drawing. There isn't a contactor on the feedback circuit stuck in?

Nothings been changed with the Pilz unit? Without looking up that particular model, some have a dial on the front to change if it is reset from a rising edge pulse or a falling edge etc...

 

[Chrishands]

I noticed only three leds. Power ch1 ch2. Atm power only is ON. I know the basic theory. I tried to sort out on my own before posting..also because it is part of my learning process to get into the subject with my effort

When today I ll have my machine I ll try everything suggested here atm and I ll tell everyone whats going on. If I will still able to write...zZz zZz...joke! Well..not really (((
I m always super careful anyway

Hi if only the power light is on, then most likely you haven't either wired up your safety circuit correctly, or you have a faulty switch on the safety side, for both channels to not be on, I have also been caught out once on an allen bradley (red) safety relay where there is a little PCB fuse located inside the front of the cover which had blown and i didnt know about it, but since your power is on its not likely to be that (just something to consider in the future)

 

[Darkwood]

Disconnect the safety loops wiring

Link out S11 - S12
Link out S21 - S22

Then put a momentary jumper across S12 to S34

If this resets the unit then the safety relay is fine.

Choose a safety loop and reconnect and retry the momentary reset as above this will identify where the issue lies.
Repeat with other loop if it seems fine.
You may also have accidently crossed over the loops so they are connected up wrong or you may have a short between them.. both these scenarios can damage some brands and models of safety relays sometimes blowing them, check the manual on that. (Some relays provide integral S/C protection)

You can choose to use other methods as a diagnostic but the above first proves your safety relay is functional.

 

[LordKelvin]

Power down the panel, and measure continuity across the push button when it's pressed.

Hi mate, not sure what you know about these Pilz units but usually you have a dual safety circuit. And a reset circuit. There is usually 5 lights. 2 lights for each chanel on your safety circuit, both these lights should be on, if so, both channels will be made. You can then push reset which should send a low voltage back to the Pilz and providing all your required chanels are closed circuit (healthy) then the pilz contactor should pull in and your 2 output lights will come on aswell as your 2 chanel lights. When you press your reset button usually it also flags a light up o the pilz to let you know its fecievi g it.


check you havent got your chanels crossed. S11 to s12 and s21 to s22

Cheers for the explanation ..the fear was you were out on site trying to repair a machines critical safety system by asking a forum ...you can understand my hesitation to go any deeper without making it clear where you may have stood.... if this is just a test rig for personal training and not out in the field then a different matter altogether and would have helped a little to know in your opening post.
http://www.is-com.ru/files/PNOZ_X2_8P_en.pdf
Right then the wiring plan is here ^^^, you can easily check if you have a faulty start button contact block or broken wire by momenterally putting a link between terminals S12 and S34, if the relay resets then the problem is in your reset loop.


If it doesn't reset then your issues may be elsewhere and again you can prove it quite simply by removing wires and fitting links on the loop inputs to prove you have no open circuits on the loop you disconnected or simply use a meter to check your loops are closed.

Cannot tell you anymore without knowing which of the systems on page 3 of the link you have.

Looks ok, quickest solution is to power the panel down, then just go point to point with a continuity meter to prove everything is as it is on the drawing.

I did all the first page of the thread except to simply connect s12 and s34 because I noticed darkwood updated in the very last post with more instructions on that side.

UPDATE: There is continuity S11, S52 --> interlock and then S34 --> INT3
S12 --> S34 is fine once I push the reset button (of course)
then S21 --> interlock and S22 --> INT3

So with the panel power down it looks like there is NO continuity in the interlocks. BUT of course they are closed when I power up the machine because I can see the green light on each of the three!

Interlock brand is MECHAN, just for info.



So and please tell me if I am wrong, the issue is not in the safety loop.

 

[LordKelvin]

There isn't a contactor on the feedback circuit stuck in?

Nothings been changed with the Pilz unit? Without looking up that particular model, some have a dial on the front to change if it is reset from a rising edge pulse or a falling edge etc...

Rob the model is PNOZ X2.8P

if there are not other considerations, I will carry on with the trials that darkwood gave to me

Please also find a further update with the feedback circuit (I believe it is this one...Am I wrong?)

 

[Bobster]

You need to prove that the Safety relay is working, so follow Darkwoods last post.

FYI - this is a manual for that safety relay.

http://www.farnell.com/datasheets/1703021.pdf

 

[Darkwood]

http://www.is-com.ru/files/PNOZ_X2_8P_en.pdf

We may be getting confused here .. which method do you think you have on page 3 of this link ...I'm under the assumption from the diagram you posted that you have a dual safety gate set up ie the 4 th down in the INPUT dual channel column... ?

This is the same connection set up with E - stops like 2nd option down same column.... connecting S11 to S52 gives monitoring of shorts between the separate loops...

PS I would also look into disconnecting all outgoing relays to ensure a fault on the 24vdc(asumming this is the control voltage) isn't dragging down the supply when you try reset you safety relay

 

[LordKelvin]

http://www.is-com.ru/files/PNOZ_X2_8P_en.pdf

We may be getting confused here .. which method do you think you have on page 3 of this link ...I'm under the assumption from the diagram you posted that you have a dual safety gate set up ie the 4 th down in the INPUT dual channel column... ?

This is the same connection set up with E - stops like 2nd option down same column.... connecting S11 to S52 gives monitoring of shorts between the separate loops...

With my humble level of knowledge of the subject, it looks like the same to me.....

 

[Darkwood]

With my humble level of knowledge of the subject, it looks like the same to me.....

They are the same just meant you using a monitored short circuit dual input set-up which is the same connections for E-Stops and Gates ...just to confirm we are all singing on the same hymn sheet here... are you using a 24v dc control for all your circuits running through the relays ...if so read my edit to last post.

 

[LordKelvin]

They are the same just meant you using a monitored short circuit dual input set-up which is the same connections for E-Stops and Gates ...just to confirm we are all singing on the same hymn sheet here... are you using a 24v dc control for all your circuits running through the relays ...if so read my edit to last post.

yes 24vdc

I do not have here a jumper...there is no other way right?

I will need to buy one then...

 

[LordKelvin]

Im wondering if I could check bit by bit instead of all together

 

[Darkwood]

yes 24vdc

I do not have here a jumper...there is no other way right?

I will need to buy one then...

All I meant by that was get a piece of wire and momentarally link said 2 terminals ...same as a link as though you were doing the job of the reset button with the short link of wire...

Site jargon --- Link - permanent connection eg 'link out terminals X an Y'
Jumper or jumper lead -a loose piece of wire for a temp' connection, I used the jumper because you don't wont to make a permanent link for the reset just mimic the action of the reset button.

When you get the hang of it you'll realise my little simple test routine takes about 2 mins and firstly confirms the relay is functional if it still has issues with loops linked out then disconnect all relay outputs to ensure no control short circuit is crashing the voltage and stopping the safety relay operating.

The hardest part usually is establishing which safety set-up has been implemented as safety relays can often be rigged up numerous ways to provide different cover and operation.

PS missed out in post 15 because you supplied the info after I posted is the link from s11 - s52 will also be required but the edit option in the forum has been reset and doesn't give you time to change things.

 

[LordKelvin]

All I meant by that was get a piece of wire and momentarally link said 2 terminals ...same as a link as though you were doing the job of the reset button with the short link of wire...

Site jargon --- Link - permanent connection eg 'link out terminals X an Y'
Jumper or jumper lead -a loose piece of wire for a temp' connection, I used the jumper because you don't wont to make a permanent link for the reset just mimic the action of the reset button.

When you get the hang of it you'll realise my little simple test routine takes about 2 mins and firstly confirms the relay is functional if it still has issues with loops linked out then disconnect all relay outputs to ensure no control short circuit is crashing the voltage and stopping the safety relay operating.

The hardest part usually is establishing which safety set-up has been implemented as safety relays can often be rigged up numerous ways to provide different cover and operation.

So I prepare a wire with two terminals and I connect with it the terminals S11 and S12, and then another one for S21 and S22.
But there will be no space to put a second terminal in S12 to connect with S34

I did not understand the difference between permanent and temporary...If I do all these connections I am cutting out all the interlocks, emergency stop buttons, Safety contactors 1 and 2, Main contactor MC and also the relay R1.....is it not dangerous if I run the machine in this configuration?

 

[Darkwood]

So I prepare a wire with two terminals and I connect with it the terminals S11 and S12, and then another one for S21 and S22.
But there will be no space to put a second terminal in S12 to connect with S34

I did not understand the difference between permanent and temporary...If I do all these connections I am cutting out all the interlocks, emergency stop buttons, Safety contactors 1 and 2, Main contactor MC and also the relay R1.....is it not dangerous if I run the machine in this configuration?

Yes just link out the terminals S11 to S12, S21 to S22 as well as another link from S11 to S52 then use a loose bit of cable to momenterally link S12 to S34.

If this then operates the safety relay it will only energise the control circuit ready for someone to push the start button or however its run...if you do not want to give them the chance to press anything just drop out your relay outputs so it will not energise the controls.

Once the unit is proven then you can remove the loop links straight away dropping the relay back out if its outputs are still connected, we are only talking a 10second window here that controls get powered so thats your call dependent on who's about, your line of sight and the risk level of the machine.

 

[LordKelvin]

Yes just link out the terminals S11 to S12, S21 to S22 as well as another link from S11 to S52 then use a loose bit of cable to momenterally link S12 to S34.

If this then operates the safety relay it will only energise the control circuit ready for someone to push the start button or however its run...if you do not want to give them the chance to press anything just drop out your relay outputs so it will not energise the controls.

Once the unit is proven then you can remove the loop links straight away dropping the relay back out if its outputs are still connected, we are only talking a 10second window here that controls get powered so thats your call dependent on who's about, your line of sight and the risk level of the machine.

There is no space in S12 and S11 to put two cables...how may I do? May I connect in another place where the "original" S12 and S11 are connected like SC1 and Emergency button?

Also, I did not understand the windows of 10sec and this:

we are only talking a 10second window here that controls get powered so thats your call dependent on who's about, your line of sight and the risk level of the machine.

 

[Darkwood]

There is no space in S12 and S11 to put two cables...how may I do? May I connect in another place where the "original" S12 and S11 are connected like SC1 and Emergency button?

Compromise 'use a connector, smaller cables or dont ferrule them ' its just a temp' thing to check if it resets

Also, I did not understand the windows of 10sec and this:

Once you test the function of the safety relay by mimic of a reset button your relay may energise the outputs, this should not set the machine running it will only energise the control options to operate the machine, if you decide to leave the outputs connected that it, as soon as you have proven the relay you can immediatly open circuit one of the links you fitted and de-energise the enabled controls... you can do thin quickly hence I said the controls will only be energised approx 10seconds so up to you if you consider this a risk... if so drop out the relay outputs and the controls will not energise... try not to over complicate it, its easy to panic when your not sure and simple tasks then become confusing.. sit back understand how the relay operates and apply our help to what you have learned.

 

[LordKelvin]

Yes I will tomorrow.

What about if I also try to disconnect all the wires from: 13 23 33 14 24 34 and keep only 41 and 42 (and of course the power for the SR A1 and A2) for the lamp and also try this...

If I power on and the button works, it might be something wrong outside the couple SR + its safety loop.

Am I wrong? (Maybe someone else adviced this but I didnt get?)



Really thanks anyway to everyone!!!

 

[Darkwood]

Yes I will tomorrow.

What about if I also try to disconnect all the wires from: 13 23 33 14 24 34 and keep only 41 and 42 (and of course the power for the SR A1 and A2) for the lamp and also try this...

If I power on and the button works, it might be something wrong outside the couple SR + its safety loop.

Am I wrong? (Maybe someone else adviced this but I didnt get?)



Really thanks anyway to everyone!!!

Lets reflect here as your getting all confused ...


Power terminals A1 + A2 power supply - leave as is.

Relay terminals ......N/C 41 - 42 usually trip indicator -leave as is.
N/O 13 - 14 / 23 - 24 / 33 - 34 (disconnect 14,24,34 if you don't want to energise the machine controls while testing unit.

Monitoring circuits
The unit has to see a closed loop between terminals S11 and S12 (this is for your loop 'A' of the E stop system)
The unit has to see a closed loop between terminals S21 and S22 (this is for your loop 'B' of the E stop system)

The unit has to see a closed loop between terminals S11 and S52 (this configures the unit to monitor any shorts between the above loops)

When the unit see's all these above conditions met on the monitoring loops then a momentary connection from S11 to S34 should operate the unit and the relays will change over to allow power to the control system of the machine.

When you understand what the unit is doing then you can decide (as I have shown you) how to confirm the safety unit is working by disconnecting loops and linking the appropriate terminals.
Once you get to grips with this one then there are many more combinations of safety relays and set-ups to work out ...this one been a very simple one to learn on.

 

[LordKelvin]

Great explanation thanks darkwood!

 

[LordKelvin]

Wow! I was able to make what you said

So this is the response:

link=my (fake) connection, real=the connection from the electrical diagram
YES=it switches NO=it does not

scenario 1 - YES
S11-S12 link
S21-S22 link
S11-S52 link
S12-S34 link

scenario 2 - NO
S11-S12 real
S21-S22 link
S11-S52 link
S12-S34 link

scenario 3 - YES
S11-S12 link
S21-S22 real
S11-S52 link
S12-S34 link

scenario 4 - YES
S11-S12 link
S21-S22 link
S11-S52 real
S12-S34 link

scenario 5 - YES (after pushing the real reset button)
S11-S12 link
S21-S22 link
S11-S52 link
S12-S34 real

I studied (well, as much as I could with my knowledge) the manual and the relay and now I believe I have got this:

The issue is in the S11 - S12 branch of the circuit.

The only thing is...what could be the problem? As I already checked there is continuity everywhere (between every two points) except before and after the 3 interlocks group...but of course they are not energised during the test (I read that I need to check continuity with the device with the power off). Also when I power on the panel, I can see the green led ON in the 3 MECHAN interlocks, that means there is a magnetic connection...

I hope I am doing well until now I am on a self-learning and also through yours (much appreciated) so be patient please with my lack of knowledge if I say something that looks "stupid"

 

[Darkwood]

Just remember just because the green light is on and the mechanical lock engaged it may be the case the integral limit switch is faulty or even a loose/broken wire, never assume always check.

Bypass a suspicious device to see if it cures the problem.

The hardest issue is having multiple faults although not as common they can be confusing at the very least.

Now you have identified the loop that is open circuit you can work your way through it... happy fault finding

 

[Bobster]

Oh be aware on a duel channel system, if both channels don't break simultaneously the pilz unit will see this as a fault and will not let you reset without cycling the power to it,

 

[LordKelvin]

So we could definitively say that the fault is in one (or more) of the interlocks?
And exactly in the wire that connect s11 with s12 right?
Thanks

 

[Bobster]

It looks that way.

 

[LordKelvin]

It looks that way.

Now it might be a good idea to study how the MECHAN safety interlock works in as much detail as I can and by pass each of them and try to sort out.

really thanks guys!

I will come back here if I will have any news

 

[Darkwood]

When you get the hang of it, this particular job wouldn't take more than half hour to diagnose the problem so we just need to speed you up a bit - 3 days and counting ... just kidding we all learn somewhere :cool3:

 

[LordKelvin]

When you get the hang of it, this particular job wouldn't take more than half hour to diagnose the problem so we just need to speed you up a bit - 3 days and counting ... just kidding we all learn somewhere :cool3:

Well now I will recover on Tuesday..stop the clock please! Ahah

I wish a good long we to everyone

 

[LordKelvin]

Problem in a wire of the first interlock. Sorted Out! Thanks a lot guys