Heater schematic

Thread Starter

Nathan Hale

Joined Oct 28, 2011
152
Hello all, hope everything is going great!

I would appreciate it if you guys can give some thought feedback on the following questions.

My good friend is trying to hookup a heater system. The schematic is the picture in black and white, and is attached down below.

My conclusions about the schematic / system are as follows:

1) I am pretty confident the black box with the Chinese characters and "110V" written on it is the power source.
2) L2 needs to be hooked up to a single hot wire coming in from the 110V "black box" power source.
3) L2 is going into the 3 ports ( which are in turn themselves individually labeled L1, L2 and L3 on the PCB, if you look closely on the board)
4) L1 needs to be hooked up to the neutral of the "black box" power supply line.
5) The third line coming out of the "black box" power supply line ( indicated by a green arrow) needs to go to ground
6) One wire needs to go from the top "G" terminal, marked by the red dot, to the ground wire mentioned in point 5 above.
7) Another wire needs to go from the bottom "G" terminal, marked by the blue dot, to the ground wire mentioned in point 5 above.
6) The hot wire coming out of the power supply and going into L2 needs to be attached to just one of the 3 screws, because the terminals are already connected through a copper jumper plate; as shown in the color picture below.
7) We should see three wires coming out of the power supply box. ( one hot, one neutral and one for ground)

Can you gentlemen please kindly put in your thoughts and tell me if my conclusions are valid, so that i can help him out? ( I am confident about my conclusions , but just want to double check so that i wont cause him a loss.)

Thank you very much for your replies.


InkedInked1_LI.jpg



3.jpeg
 
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Tonyr1084

Joined Sep 24, 2015
4,180
AC IN at (black and white drawing) L2. L1 is the neutral line. The wire with the green arrow is also neutral AND ground. In the first drawing (the first photo) is a wire identified as L2. It appears to be the 110 VAC connection. It is connected to the board with a triple jumper and all three of those screws are identified as AC IN, L1, L2 & L3. At the opposite end of the board are three more terminals marked AC OUT, L1, L2 & L3. What this suggests to me is that power applied at the first "L1" is a part of the circuit that leads to the other "L1" and is controlled by a single relay. Each other one (L2 or L3) is also controlled by its own relay. Each is an AC source for one of the heaters. Same is true of L2 as is also the same for L3. Since the other end is similarly marked with L1, L2 and L3, each controls a single segment of the heater, exactly as it is drawn. Those are the "Power Lines". The middle four screws are for neutral and ground. I don't think it's a good idea to have ground connected the way the board does it - but I can't say for sure. But it appears as though there's a common trace between all four of those screws.
 
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Thread Starter

Nathan Hale

Joined Oct 28, 2011
152
......... white drawing) L2. L1 is the neutral line. The wire with the green arrow is also neutral AND ground. In the first drawing (the first photo) is a ...........
Thank you for your reply. Can you please tell me why, "The wire with the green arrow is also neutral AND ground" ?
I thought the wire with the green arrow is ground and the wire labeled L1 is Neutral. I am thinking that both are two completely different wires and dont connect with each other, ever.
Thank you for your reply.
 

Thread Starter

Nathan Hale

Joined Oct 28, 2011
152
Hello all again! Hope all is well. I was wondering if you could please kindly answer a few questions about the schematic below:

a) What does that black line ( pointed by the red arrow) going from the transformer to the bottom of the board ( indicated by the blue arrow) doing? Is it telling us that there is a wire running from the transformer towards the bottom of the board?

b) Do you see the red circle below? Does the line L2 end up becoming 330 V ( 110v x 3 ) ? I came to this conclusion because we have one 110V line going in.

c) How is the transformer miraculously getting 240 v? Is something happening under the board where two 110 v lines are somehow being combined to give it 240 v ?

Thank you very much for your replies.

1581559902484.png
 

Attachments

dendad

Joined Feb 20, 2016
3,322
a) What does that black line ( pointed by the red arrow) going from the transformer to the bottom of the board ( indicated by the blue arrow) doing? Is it telling us that there is a wire running from the transformer towards the bottom of the board?
That is the 2 pin plug that supplies 220V power to the 12V transformer. Can you see if one side of the white connector goes to the Neutral, or is it across 2 "L2" wires?
b) Do you see the red circle below? Does the line L2 end up becoming 330 V ( 110v x 3 ) ? I came to this conclusion because we have one 110V line going in.
c) How is the transformer miraculously getting 240 v? Is something happening under the board where two 110 v lines are somehow being combined to give it 240 v ?
If it was for Australia, that would be 3 phases, with 240V measured between any 1 and Neutral. Not 330V
In the US, 220V is from a split transformer, 110V-0V-110V giving 220V across the winding. This is still the same phase, just the other end of the transformer. Referred to as "Split Phase" I believe.
You need to determine if the circuit needs actual 3 phase power, not a split phase supply.
Maybe it will be worth getting a qualified electrician to look at it.
 

Tonyr1084

Joined Sep 24, 2015
4,180
How does this fact change the dynamics of the situation? Are both those wires ( the green arrow wire and L1 ), eventually supposed to be connected to each other?
Thank you
Normally in a home (220VAC Line to Line or split (line to neutral) 110 VAC) the neutral returns to the panel directly and separately from the ground line. In the box (older homes anyway - I'm not an expert on electrical standards in US or elsewhere) Both neutral and ground are tied together. But that's inside the box. Providing a different pathway for neutral and ground is a safety factor that in the event neutral should fail ground remains unaffected.

You ask about the transformer. Nothing special going on there. The line (L2) provides the necessary power for switching. Normally electric heat is 240 VAC, so it's probably assumed you're connecting to 240 VAC (220). If you're using it on 110 VAC then you would need the appropriate transformer that can supply 12 V at the rated current necessary for the electronic control circuitry to work properly. You may need a 120 to 12 volt transformer.
 

MisterBill2

Joined Jan 23, 2018
5,227
AC IN at (black and white drawing) L2. L1 is the neutral line. The wire with the green arrow is also neutral AND ground. In the first drawing (the first photo) is a wire identified as L2. It appears to be the 110 VAC connection. It is connected to the board with a triple jumper and all three of those screws are identified as AC IN, L1, L2 & L3. At the opposite end of the board are three more terminals marked AC OUT, L1, L2 & L3. What this suggests to me is that power applied at the first "L1" is a part of the circuit that leads to the other "L1" and is controlled by a single relay. Each other one (L2 or L3) is also controlled by its own relay. Each is an AC source for one of the heaters. Same is true of L2 as is also the same for L3. Since the other end is similarly marked with L1, L2 and L3, each controls a single segment of the heater, exactly as it is drawn. Those are the "Power Lines". The middle four screws are for neutral and ground. I don't think it's a good idea to have ground connected the way the board does it - but I can't say for sure. But it appears as though there's a common trace between all four of those screws.
It is a double sided circuit board and so the L1, L2, and L3 are not tied to each other..

It looks a lot like the control for a high power demand type water heater that was given to me to see if there was any way to reduce the power required. THAT water heater required THREE 40 amp circuits for operation. The folks had wanted to install it in a cottage with what appeared to be 30 amp service.
 

shortbus

Joined Sep 30, 2009
7,461
Normally in a home (220VAC Line to Line or split (line to neutral) 110 VAC) the neutral returns to the panel directly and separately from the ground line. In the box (older homes anyway - I'm not an expert on electrical standards in US or elsewhere) Both neutral and ground are tied together. But that's inside the box. Providing a different pathway for neutral and ground is a safety factor that in the event neutral should fail ground remains unaffected.
I'm with Dendad on this, it's supposed to be on 3 phase. 220VAC is only L1, L2 and a neutral, not L1, L2, L3 and neutral.
 

Tonyr1084

Joined Sep 24, 2015
4,180
Here's why I'm suggesting that the AC IN, L1, L2 and L3 are jumpered together.

1581639597506.png

And given this image:
1581639677569.png

I've never known three phase to be jumpered together. Since there are three distinct heaters and what appears to be three individual relays - my money is on "L1 IN is connected to L1 OUT via a relay". Same for L2 and L3, each individual heater (as shown in the drawing) is its own circuit, controlled individually by the control board and associated relay. The only common point they share is the neutral return line, marked "N" on the board and the "G", which appears to be traced together on the circuit board.
1581641244473.png

It COULD be that three individual heater elements can be individually controlled. Turn on one heater for one zone, another heater for another and a third for the third zone. Maybe not. But from what I see - - - . Disagree if you feel you need to. I'm going with what I posted, and I stand by it. Double sided or not.

What may be adding to confusion is the drawing calling L2 a 110V line while the board is labeled with AC IN L1, L2 and L3. Also, the drawing shows a wire labeled L1 connected to the board and is identified ON THE BOARD as "N" (or Neutral). Above the N is a G (black & white photo), assumably for Ground. The color photograph shows what the B&W photo calls "G", the color photo is marked with a ground symbol.
 
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Thread Starter

Nathan Hale

Joined Oct 28, 2011
152
It is a double sided circuit board and so the L1, L2, and L3 are not tied to each other..

It looks a lot like the control for a high power demand type water heater that was given to me to see if there was any way to reduce the power required. THAT water heater required THREE 40 amp circuits for operation. The folks had wanted to install it in a cottage with what appeared to be 30 amp service.
Yes, it is for a steam generator. Thank you for your reply.
 

Thread Starter

Nathan Hale

Joined Oct 28, 2011
152
Normally in a home (220VAC Line to Line or split (line to neutral) 110 VAC) the neutral returns to the panel directly and separately from the ground line. In the box (older homes anyway - I'm not an expert on electrical standards in US or elsewhere) Both neutral and ground are tied together. But that's inside the box. Providing a different pathway for neutral and ground is a safety factor that in the event neutral should fail ground remains unaffected.

You ask about the transformer. Nothing special going on there. The line (L2) provides the necessary power for switching. Normally electric heat is 240 VAC, so it's probably assumed you're connecting to 240 VAC (220). If you're using it on 110 VAC then you would need the appropriate transformer that can supply 12 V at the rated current necessary for the electronic control circuitry to work properly. You may need a 120 to 12 volt transformer.
UPDATE:

After digging more into it, and contacting the seller of the device, my friend says it is calling for 220 volts. The Chinese characters are saying "twice" 110V.
Now, with this new info on hand should L1 and L2 be treated as two hot wires?

Also, the more important question that is popping up is why are they asking for a hot line to go to the neutral terminal, and then tying neutral and ground?


Please refer to the 2 pictures above.
Thank you for you reply.
 

Tonyr1084

Joined Sep 24, 2015
4,180
Twice 110V; I can see how that may be. However, L1 (not L1 on the board) appears to be connected to the neutral and ground terminals, which, unless I'm missing something, could be a problem. Hooking a live line directly to a ground line should not be. Refer to the third picture posted in post #12 where it appears, or fails to show separation, neutral and ground seem to be connected. If neutral and ground are NOT directly connected then yes, it all makes sense. However, I still don't see this being three phase.

To address your "More important question" - it probably isn't connected. If it were it would be a dead short to ground.

The way I see the circuit is that L1 IN and L1 OUT (on the board) are control circuits. I can only say this speculation is that you can use that to control any voltage and any amperage the relay is rated for. You COULD (again, I'm speculation) use it to control 12 volts DC at 40 amps (IF the relays are rated for that). All that aside, Circuits L1, L2 and L3 are just switches between a source and a load.

After some consideration "Ground" and "Neutral" are probably isolated from each other. However, I'm wondering exactly what ground is connected to. Can you get some clearer pictures of the four screw terminals in the middle from some different angles with different angles of lighting so it might be clear whether ground and neutral are tied together or are separate. Also a picture of the bottom side of the board, which will reveal hidden traces and clear up any remaining confusion.
 
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You need to determine that the ground and neutral terminal are not tied on the board. If so, do not use this circuit. If OK, it really looks like it is intended for three phase power, but it might work on 120/240 as long as the transformer gets 240 volts. But since each heater is tied from one of the "L's" to neutral, one side of the 120/240 circuit will have twice the load. The mains breaker will need to be sized accordingly.
 

MisterBill2

Joined Jan 23, 2018
5,227
I mentioned once before that the heater that I have required THREE 40 amp circuits, for as total draw of 120 amps at maximum heat. There was no mention in the instructions about single phase, split phase, or three phase. The reason is that #8 wire is a lot easier to work with than the #2 wire to feed it all into one terminal.
 

be80be

Joined Jul 5, 2008
2,006
MisterBill2 is dead on what you have is you supply 3 number 8 wires coming from 3 breakers on one side of the panel so you have 2 hots that are in phase and one that's not so you would end up with 3 120 volt from hot to neutral and at the bottom where the transformer hooks up will be 240 volt give or take

And it doesn't matter if it 3 phase 208 or single phase 240 it will still work.
I hook this stuff up all the time some even use a 120 volt transformer so it don't matter if all the line are breaker down.
but most are like this one. it on demand heater with 3 120 volt element
 

Tonyr1084

Joined Sep 24, 2015
4,180
MisterBill2 is dead on what you have is you supply 3 number 8 wires coming from 3 breakers on one side of the panel so you have 2 hots that are in phase and one that's not so you would end up with 3 120 volt from hot to neutral and at the bottom where the transformer hooks up will be 240 volt give or take

And it doesn't matter if it 3 phase 208 or single phase 240 it will still work.
I hook this stuff up all the time some even use a 120 volt transformer so it don't matter if all the line are breaker down.
but most are like this one. it on demand heater with 3 120 volt element
I agree; Mr. Bill IS dead on about the three heaters. Please note that each heater element is tied back to neutral. If it were three phase then the heaters could be drawn as a triangle with one phase going to each point - but no neutral. Not sure how it would work if you connected it to three phase. But again, with three phase, you don't have a neutral connection.

AND it could be said that the control board is powered from 12 VAC, regardless of how it's derived. Each line element of the relay board controls a single element - whether it's a heater or a light bulb or anything else, the relay is merely a switch between L1 AC IN and L1 AC OUT. You can use it for whatever the relay is rated for. In the case of the black n white drawing - it shows the system being connected to three heaters each running from a 220 line ("twice 110V").

If it's being used as a heater then hook it up the way it's drawn. On the B&W drawing, connect the hot to the bottom three terminals. The heaters are connected to the top three terminals (as pictured in the color picture).

Three phase:
1582076240423.png
 
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be80be

Joined Jul 5, 2008
2,006
I'm sure how it works lol it's made as I said they got 3 120 volt elements you hook one side to the neutral and one side to 120 volt hot leg
It don't matter if that's 208 3 phase or 240 single

And 208 3 phase is 4 wires 3 hot and neutral
You get 120 volts hot to neutral or 208 between two legs

The 240 single is 120 to neutral and 240 to hot to hot leg
 
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