Control Panel for 3ph Heaters

[jparker86]

The control relay will still drop out when the thermostat operates. The stop is in the wrong place and there's no need for the Aux on the contactor.

Yeah sorry I just realised that I wont need that Auxillary anymore because their will be a constant supply to A1.
Why will the control relay still drop out when the thermostat operates? How can i change it?

 

[jparker86]

How does this look

 

[Knobhead]

I give up!

Follow the last drawing I've given you. It will work with no problems.

 

[jparker86]

I give up!

Follow the last drawing I've given you. It will work with no problems.

Tony I don't mean to offend you but your drawing makes no sense to me. I'm here because I need help. Again something that seems relatively straight forward to you is in actual fact very difficult to me.

 

[Darkwood]

I think you are struggling because you cant interpret tony's wiring diagram because you dont understand what the R1/1 etc means ....
R1 relates to relay 1
R1/1 relates to relay 1 and the first pole/way so looking at the diagram when you press the start button R1 will close.... this will close R1/1(pole no1) and because its in parallel with the start button it holds R1 closed.
R1/2 is the second pole of R1 so when R1 closes R1/2 becomes energised supplying the next part of the control circuit.

Try reading the wiring plans now with this info..... my worry is you will need to supply a wiring schematic with your control panel yet you can't initially read them yet alone draft one up.

 

[jparker86]

I think you are struggling because you cant interpret tony's wiring diagram because you dont understand what the R1/1 etc means ....
R1 relates to relay 1
R1/1 relates to relay 1 and the first pole/way so looking at the diagram when you press the start button R1 will close.... this will close R1/1(pole no1) and because its in parallel with the start button it holds R1 closed.
R1/2 is the second pole of R1 so when R1 closes R1/2 becomes energised supplying the next part of the control circuit.

Try reading the wiring plans now with this info..... my worry is you will need to supply a wiring schematic with your control panel yet you can't initially read them yet alone draft one up.

Hi Darkwood, I am confused because Spark's drawing doesn't mention a relay. This one does? I have loads of contactors, but no relays in my stock and wanted to make it this week? So are we saying Sparks drawing will not work?

 

[Darkwood]

Tony has supplemented relays to do the control side as they are cheaper, less room etc, the contactors are just larger versions of relays for the heavier loads.... take the both as meaning the same if you have all contactors.

 

[jparker86]

Tony has supplemented relays to do the control side as they are cheaper, less room etc, the contactors are just larger versions of relays for the heavier loads.... take the both as meaning the same if you have all contactors.

Thanks,I apprechiate that but just want to work it with contactors.
8 don't want to confuse myself any more lol.

What wwould I need to do to get my current drawing work? I thought I did it just like spark said?

 

[spark 68]

You have shown a diagram with 2 contactors on, K1 is you initial latching contactor (k1/1), k2 is your first heater control and using the common connection K1/2 to supply you 2nd heater would be fine, less expensive and leave more room as it removes the need for the extra contactor. (excluding E-stop and pump controls)

Hi DW,
K1 could easily be a relay instead of a contactor (cheaper) as the control element in my drawing, K 1-1 and K1-2, are 2 pairs of contacts on the K1 relay, K2 is a 3 or 4 pole contactor which has the stat or cutout in series with the control coil.

I had cut this drawing down to it's most basic skeleton, the OP could have used extra contacts on the start/stop relay for status indicators and the like.

I had initialy assumed the OP was controlling both heaters from one stop/start circuit, but then he wanted to control both heaters seperately, hence the mention of three contactors initially, revised to four, to give independent control to each.

Half the trouble I had was the actual drawing with the software package (Tinycad), as Iam not used to drawing in software.

This was the circuit for one heater, as I said he would need to duplicate this circuit (apart from the E-stop) for additional heaters.

 

[jparker86]

Hi DW,
K1 could easily be a relay instead of a contactor (cheaper) as the control element in my drawing, K 1-1 and K1-2, are 2 pairs of contacts on the K1 relay, K2 is a 3 or 4 pole contactor which has the stat or cutout in series with the control coil.

I had cut this drawing down to it's most basic skeleton, the OP could have used extra contacts on the start/stop relay for status indicators and the like.

I had initialy assumed the OP was controlling both heaters from one stop/start circuit, but then he wanted to control both heaters seperately, hence the mention of three contactors initially, revised to four, to give independent control to each.

Half the trouble I had was the actual drawing with the software package (Tinycad), as Iam not used to drawing in software.

This was the circuit for one heater, as I said he would need to duplicate this circuit (apart from the E-stop) for additional heaters.

Spark what you say is exactly what I want.
What I did on the paper above is what I think your drawing is telling me to do.
My drawing will be replicated for the 2nd heater as per your post, except for emergency stop which kills all three (2 pumps and heater)
What I'm asking is what's wrong with how I've drawn it out?

 

[spark 68]

Spark what you say is exactly what I want.
What I did on the paper above is what I think your drawing is telling me to do.
My drawing will be replicated for the 2nd heater as per your post, except for emergency stop which kills all three (2 pumps and heater)
What I'm asking is what's wrong with how I've drawn it out?

All of the contactor/relay contacts on my drawing are normally open (N/O)

 

[jparker86]

All of the contactor/relay contacts on my drawing are normally open (N/O)

Hi Spark,
Yeah my contactors are all NO. I have removed the auxillary but Tony said in his previous post that the stat will kill the power to the controlling contactor. That is what has confused me.

 

[spark 68]

Hi Spark,
Yeah my contactors are all NO. I have removed the auxillary but Tony said in his previous post that the stat will kill the power to the controlling contactor. That is what has confused me.

Iam not sure if Tony was referring to your drawing (I suspect he was), as with mine the start/stop relay will remain closed (unless the stop or E-Stop is activated) regardless of the stat status.

On my drawing K1 is the control element to K2, K2 is the stat controlled switch which actully turns the heater on and off when the stat dictates.

 

[spark 68]

Does this help any ?

I have drawn the box around K1 contacts, and the coil for K1 is shown seperate, as is K2 coil, I have added the A1 and A2 labels too.

 

[jparker86]

Yes I think it does. I will give you my "amateur" drawing and see if it looks good.

 

[Richard Burns]

Sorry to jump in here, but I think Spark68 has the easiest solution with your control setup, I am not sure on your diagrams how you have set this up.
Each heater has a latching contactor control by momentary start stop buttons.
This controls another contactor, through the stat control to operate each heater.
The pump control is a straightforward single latching contactor.


I think that this diagram is a simple layout (from a simple person) of what Spark68 has said.

 

[jparker86]

Sorry to jump in here, but I think Spark68 has the easiest solution with your control setup, I am not sure on your diagrams how you have set this up.
Each heater has a latching contactor control by momentary start stop buttons.
This controls another contactor, through the stat control to operate each heater.
The pump control is a straightforward single latching contactor.


I think that this diagram is a simple layout (from a simple person) of what Spark68 has said.

View attachment 13991

Excellent- The only thing I do not have is a panel start and panel stop. Just an Isolator switch, then the e/stop finally start and stop buttons for each control.

 

[Darkwood]

View attachment heater circuit.pdf

Here try following this chopped down version as its in standard wiring format and youll need to learn to read them its a copy of Tony's plan with only 1 heater and no pump or E-stop just to allow you to follow it easier.
Ive explained how the marking system functions and hopefully will enlighten you to be able to follow them.

 

[Richard Burns]

Excellent- The only thing I do not have is a panel start and panel stop. Just an Isolator switch, then the e/stop finally start and stop buttons for each control.

That is immaterial, your panel start and stop switch are just combined in one isolator and are not momentary.

 

[jparker86]

View attachment 13992

Here try following this chopped down version as it in standard wiring format and youll need to learn to read them

Hi Darkwood,

Richard Burns has given me a broken down drawing with contactors and if possible I want to stick with them. I really do appreciate all your help. If any of you are interested in making these for me in future I am open to quotes. This has taken up already too much of my time and think in future ill leave it to the professionals.

 

[jparker86]

That is immaterial, your panel start and stop switch are just combined in one isolator and are not momentary.

So I do not need a panel start and stop?

 

[Richard Burns]

Your panel start / stop is the isolator.
I have modified the diagram to show a single switch (which is the isolator).
It would help you to be able to understand the proper wiring diagrams so do not discount Tony, darkwood and Spark68 contributions, these are the ones that will make the difference and be of most use in the future. Do try and read and understand them, even if only for future reference.

 

[Darkwood]

Ok JP but do have a gander and see if you start to follow what its all about, this will be the type of plan usually found with machinery and control boxes and if you expect to have future interests in that area its well worth learning the basics....

well done Rich' succeeded where many have failed arty: OP seems happy with it but he'll rarely come across such a layout in the real world....well maybe on the wiring bumf with a start stop contactor manufacturers connection plan and cheers JP for the challenge of doing a 1day wonder course on on the teachings of schematics

 

[jparker86]

Ok JP but do have a gander and see if you start to follow what its all about, this will be the type of plan usually found with machinery and control boxes and if you expect to have future interests in that area its well worth learning the basics....

well done Rich' succeeded where many have failed arty: OP seems happy with it but he'll rarely come across such a layout in the real world....well maybe on the wiring bumf with a start stop contactor manufacturers connection plan and cheers JP for the challenge of doing a 1day wonder course on on the teachings of schematics

lol Thanks Darkwood. The problem I have/had is just understanding these drawings, but again if anyone is interested in making these for me in future please inbox me.

 

[Darkwood]

I lack the time unfortunately you could ask tony as he dont do alot all day :lol:

next things to look at regarding your control is E-stop, and whether its required as you have only fitted it as a latching stop button and not wired it as a true e-stop circuit, for the basics of your water heater and pump im not too sure you'll actually need one, as mentioned before a risk assessment needs doing as to the level of possible injury and/or death by an operator and the resulting catagory will give the degree of protection needed.... as your system has been explained it dosn't sound like it warrants an E-stop option.

 

[Darkwood]

My last note would be to avoid confusion and uncertanty you should fit a row of indicator lamps to signal what is on, anyone walking up to the panel wont be any wiser as to the operational state its in, using a N/O contact (aux if necessary) wire a control on lamp, heater 1, heater 2 and pump lamps as well as a initial power lamp....... i think you'll start to appreciate how a good background is needed before designing and building a panel on your own.
Personally i would have fitted a plc programmed it up lost a few relays added a flow sensor and temp read-out as well as a overtemp sensor all controlling the system in case of problems.... yes a little more advanced but giving it the PRO - touch.
Your system is functional but as it stands it is functionally confusing as to what it on and off at any given time and at a minimum id implicate indication lamps.

 

[spark 68]

Another thing I would look at, is providing indicator status lamps for the various items, when you get it working.
You could use the spare contacts on the stop/start contactors (terminals 5&6 on Richards drawing).

As DW said it is debateable whether you actually need an E-Stop or more correctly EPO (Emergency Power Off).

Cross posted with DW above lol

 

[jparker86]

My last note would be to avoid confusion and uncertanty you should fit a row of indicator lamps to signal what is on, anyone walking up to the panel wont be any wiser as to the operational state its in, using a N/O contact (aux if necessary) wire a control on lamp, heater 1, heater 2 and pump lamps as well as a initial power lamp....... i think you'll start to appreciate how a good background is needed before designing and building a panel on your own.
Personally i would have fitted a plc programmed it up lost a few relays added a flow sensor and temp read-out as well as a overtemp sensor all controlling the system in case of problems.... yes a little more advanced but giving it the PRO - touch.
Your system is functional but as it stands it is functionally confusing as to what it on and off at any given time and at a minimum id implicate indication lamps.

Hello Darkwood,
Yep I already have the wheels in motion for this- it would have two indicator lamps. One to show the heater is active and another to show it is drawing heat.
Im just thinking on the drawing that has been done, can I use a 2 pole instead of the three shown?

 

[Darkwood]

If a third pole isn't required then you can fit the 2pole i think you shown earlier, the calling heat lamp can just be connected to the stat sw wire as the same with any other lamp just double up in the circuit where it requires a signal, although when you advance you will design the lamp indication etc through there own aux contacts but no harm in doubling up on your learning curve. Also for future ref.... control voltages are usually reduced to both heighten safety and allow to export control circuits and sensing outside the panel itself in a safe manor...24v dc is common but can vary in the industry.... last note would be to run slotted trunking to neaten your control system it may mean a larger box but looks more pro'.

 

[Knobhead]

you could ask tony as he dont do alot all day :lol:

Cheeky sod!

JP a latching stop P/B does not meet the requirements of an emergency stop.

 

[Darkwood]

Heres a recent one i did just to express the slotted trunking suggestion and how neat a simple cheap addition actually looks.

 

[jparker86]

View attachment 14003 Heres a recent one i did just to express the slotted trunking suggestion and how neat a simple cheap addition actually looks.

Can you enlarge it?

 

[Darkwood]

Can you enlarge it?

im trying bare with me

 

[jparker86]

im trying bare with me

Darkwood thanks for bearing with me.
As I said I only need two poles so you think that contactor I posted earlier with 1,2,3,4 + A1 + A2 will be ok? It doesn't have any NO contacts though. But looking at this drawing it doesnt matter? Correct?

 

[Darkwood]

Trying to see if can get it larger.

Contactors are generally N/O ..this is the de-energised state the one you have i assume has 2 N/O poles that close when coil is energised, re' this pick it would normally not be as tight and compact but has some space restrictions as it was a sample and will have all its internals removed and fitted into a main cab of a larger control system, also due to this just been a temp' set up ive left out a cooling fan and filter just in case any keen eyes try pulling me on it.

 

[jparker86]

Wow that looks ace Darkwood. This is what I will hopefully one day achieve lol.
So what I will do now is go home and try and figure out what you guys have done and report this evening with another drawing.

 

[Darkwood]

:blush5:...... believe it or not this is a simpler set up than yours, dont get overwelmed by the drives but it was rushed and i was restricted with spec's on the cab' size so got a little more crowded than i like, only difference here to yours is the trunking and the numbering of all cables but you can see what a £10 worth of extra gear can achieve.

 

[jparker86]

:blush5:...... believe it or not this is a simpler set up than yours, dont get overwelmed by the drives but it was rushed and i was restricted with spec's on the cab' size so got a little more crowded than i like, only difference here to yours is the trunking and the numbering of all cables but you can see what a £10 worth of extra gear can achieve.

You see as much as I would love to pay someone to do the job first time around, I love to know how things work.
When I sell a pce of equipment I love to know how each and everything works. Before I come on this forum I wasn't that clued up on how a contactor worked, etc... and to be honest I am probably still a bit lost but at least now if anything goes wrong or the customer asks me a question I can give him an answer based on my experiences and that in my business is priceless. I hate nothing more than speaking with someone about something and he says "Ill have to ask my boss...".
I have drew the control circuit out on paper and see what you think. Please let me know if I have got all the wires going to the correct place. (please ignore the writing diagram which doesnt have anything going to A1!)

 

[Darkwood]

it would function but it is poor design, consider a latching stop button or holding stop in, at the same time push start this will pull the contactor in, your stop button should be before the start in series and take your latching relay source from the outgoing off the stop button, this way it breaks both power to the start button and power to the latch loop.
Put your stop before your start in series then take your supply to terminal marked 2 from the out going of the stop or input of the start (same thing)

If you follow that ....now if you hold stop in and press start it wont pull the contactor in.

 

[Knobhead]

When I sell a pce of equipment I love to know how each and everything works.

Out of curiosity what do you normally sell?

 

[jparker86]

Out of curiosity what do you normally sell?

I sell industrial equipment that filtrates liquid into a 5 micron level ensuring particle free liquids. Mainly aimed at oil people who buy and or collect used vegetable oil and want it filtering down to remove solids.

 

[spark 68]

Hi JP,

Try this

 

[jparker86]

Hi JP,

Try this

Thanks Spark, I was following the drawing cause it says on the drawing to have the stop button interrupt the live into l1? Is this not correct?

 

[spark 68]

Thanks Spark, I was following the drawing cause it says on the drawing to have the stop button interrupt the live into l1? Is this not correct?

On the drawing I did, the stop is above the start button, it is just conventionally done this way, as it interrupts both the coil and the contact.

In fact the drawing I gave you is more like this:

Edit: Drawing corrected after Richard pointed out my mistake

 

[jparker86]

I think part of my trouble was understanding how the start button stays closed when it's normally open. Am I correct in saying that the moment the start button is pressed it is feeding in a loop and as a result stays retained

 

[spark 68]

I think part of my trouble was understanding how the start button stays closed when it's normally open. Am I correct in saying that the moment the start button is pressed it is feeding in a loop and as a result stays retained

Your start button is N/O , it closes temporarily (when you press it), this energises the coil pulling in the contacts, one of the contacts then keeps the coil energised even after the start button has opened again (finger off), ie. it is self sustaining, until you break the circuit again with the stop button.

 

[Richard Burns]

The "switch" 1-2 is supplying the coil in parallel with the start supply. Once the contactor is energised using the start button it closes 1-2 which then supplies the coil and so keeps the contactor actuated.

To stop the contactor you need to interrupt the supply going to 2 to deactivate the contactor, the two mods above would leave the contactor actuated, as they are disconnecting the start button supply to A1, perhaps try this.
Edit talking rubbish here, this would not work, you could never start!


Edit2 the stop button is NC so it would work, what an idiot, think before posting!!!

 

[spark 68]

You are of course 100% correct Richard, my mistake LOL, Iam in the middle of filling in an EIC and not paying attention.

I will edit the above drawings.

Edit: I did make a mistake on my drawing too though Richard, it's that time of night on a Friday lol.

 

[jparker86]

Ok so the above drawing would work?

 

[Richard Burns]

Sorry Jp all gets a bit vague at this point.

My drawing in post 97 would work and would disconnect the contactor when you press the stop button, however this would not disconnect the supply to terminal 3 in the drawing (although the contactor being off would stop the supply to the stat). Spark68 has edited his picture in post 94 so that all the supplies to all the terminals in the contactor (bar the neutral) will be disconnected by the stop button and will also work and be more secure (in case of the contactor welding closed, etc.)