Electrical help for last phase

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Brewpastor

Beer, not rocket chemistry
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I am almost finished with my switch and heater project. I have a 240 GFCI in place, and all the wiring finished except for my 2 pole switch and Rancho controller. And I need help with these.

CIMG1981.jpg


My set up is 240. The rig plugs into a 60 amp circuit. On the rig I have a secondary circuit box with a 50 amp GFCI in it. This runs off to be split so that the 110 V pump and outlet gets power and the 240 V water heater element gets power. The 2 pole switch and controller are in-line with this heater. the 240 goes to the switch, then the controller and then the heater.

An electrician friend is going to come and give everything the once over, but I have worked it out with him that I will have all the pieces in place so he doesn't have to take too much time with it.

But I am not clear how the wire the switch or the controller and need help. Any takers?
 
Yuri_Rage said:
This seems to be pretty clear - let me know if you need more explanation. Looking good, BP!

4688-ranco240.jpg

And so my assumption is that I will run one of my positive lines and my nuetral/common line (leaving the second positive line out of this loop). Correct?

What then about the 2 pole switch? Attach both of the positives and by-pass with the common?
 
Brewpastor said:
And so my assumption is that I will run one of my positive lines and my nuetral/common line (leaving the second positive line out of this loop). Correct?
If you run only one hot line + common through the Ranco, you will power it with 120VAC. It will work, but you'll have to get that other hot line to your load somehow. If you run one hot + common to the Ranco, and the other hot + common to the load, you'll constantly have 120VAC at each, with 240VAC available when the Ranco switches - probably not what you want.

I'd probably run both hot lines through the Ranco and to the load, skipping the common (how most welders are wired, and how the diagram shows it). Just make sure everything is well grounded.

I hope this isn't too confusing...re-reading it makes me want to word it differently, but I'm not sure how.

Brewpastor said:
What then about the 2 pole switch? Attach both of the positives and by-pass with the common?
That's what I would do. It's good use of a DPDT switch - switching all possible current paths from a 240VAC source.
 
Yuri_Rage said:
If you run only one hot line + common through the Ranco, you will power it with 120VAC. It will work, but you'll have to get that other hot line to your load somehow. If you run one hot + common to the Ranco, and the other hot + common to the load, you'll constantly have 120VAC at each, with 240VAC available when the Ranco switches - probably not what you want.

I'd probably run both hot lines through the Ranco and to the load, skipping the common (how most welders are wired, and how the diagram shows it). Just make sure everything is well grounded.

I hope this isn't too confusing...re-reading it makes me want to word it differently, but I'm not sure how.


That's what I would do. It's good use of a DPDT switch - switching all possible current paths from a 240VAC source.

So, what the diagram shows as a common is actually the second positive, and the neutral bypasses the controller, as does the ground and proceeds to the heating element where everything is attached?
 
Brewpastor said:
So, what the diagram shows as a common is actually the second positive, and the neutral bypasses the controller, as does the ground and proceeds to the heating element where everything is attached?
Yes - the second "leg" of the 240VAC source (on the right) connects to the post labeled "COM" on the controller.
 
Very cool and very easy.

Oh this is going to be a great addition to my set-up! Mobile, thermostatically controlled, electric heat for whatever purpose there may be: heating mash water, RIM, modivating the kids...
 
Yuri_Rage said:
One more thing:

If your switched components require a connection to common, I suggest using the Ranco to trip a 240VAC DPDT relay (sometimes called a contactor). That way you won't have any stray current coming from that constantly hot leg.

Links to parts (I'll edit as I find them):
10A DPDT relay from Jameco
20A DPDT relay from DigiKey
30A DPDT relay from ABS Alaskan


I agree with this also, run 120v to the controller to switch a 240v relay. Its a much safer way to go.

I wanted to control the 240v element seperately from the pump but run them both from the same controller. I ran 120v to the controller and bought 120v powered relays to switch both 120v and 240v.

I used SPDT switches to switch from the heating element to the pump or run both at the same time.

Relays will give you more flexability for switching multiple things.
 
Yuri_Rage said:
One more thing:

If your switched components require a connection to common, I suggest using the Ranco to trip a 240VAC DPDT relay (sometimes called a contactor). That way you won't have any stray current coming from that constantly hot leg.

Links to parts (I'll edit as I find them):
10A DPDT relay from Jameco
30A relay from ABS Alaskan

I think it is set up for just the 2 "hot" legs. It has 4 connections plus a ground connection. Two on each side, bottom screws are black, top screws are brass, the ground is green. I am figuring it is one hot in on each side (bottom) two hots out on each side (at the top).
 
Monster Mash said:
Its a much safer way to go.
\

Why is it needed (safer) if the system is run through the GFCI? I am not arguing the issue, just seeking clarification. If it is neede then I will put it in, but if I can save the $30 that would be nice as well!
 
When using the controller to switch 240v you can only switch one leg which means you will always have 120v live to the heating element. It will switch the element on and off but you will always have power at the connection.

A DPDT relay will switch both legs of your 240v turning it off completely.
 
The output of the controller is a single relay, you can't switch both wires. The other leg that goes into the controller does not get switched, it completes the circuit for both the controller and the element and it is always powered.
 
Brewpastor said:
So, where does the relay go in the sequence. Would it work between the 2 pole switch and the controller?
Schematic for 240VAC control of the relay:

4688-bpschematic.JPG


Both leads from the source are hot. Common is not depicted here.
 
Get a 110v switched relay and use the Ranco to switch the 110v to the relay.

Both sides of the 240v line goes straight through the relay. Here is a pic of the relays I used, I should have used two black wires on the output because it would confuse most electricians.

The small solid state relays on the sides are for 120v, the two large contactors are for 240v. The contactors are capable of switching 3 lines at once but for elements you only need two. The 120v coil is under the contactors and connected to the controllers which pulls them closed.

DSCN3025.jpg
 
I prefer to have the 120v side on a seperate breaker rather then splitting it like Yuri shows. If you get a short on the 120v side it might not trip the breaker. I split the 120 and 240 in the panel with seperate GFCI breakers for both to be safe.

Getting complicated isn't it?....:drunk:
 
It isn't as confusing as it first seemed. This is really helpful. But yes, it is complicated. Fun and interesting, but complicated!

Yuri, thanks for the diagram. It is helpful as well.

Monster Mash, one of my hopes was to utilize a leg of the 240 to power the 110 equipment on my rig as well as the heating element. I have the amps to do this and the gauge of wire to handle the load. Doing this would simplify the set-up by reducing the amount of cords to one that I would need to plug the rig in. I assume from what you are saying that you would not recommend this. Right or wrong and again your explanations are helpful.

I know it has not been said before, but this forum is great. Thanks folks.
 
If you have 240v coming out to the brewery you will need a sub panel to handle a 240v and a 120v breaker. They have spa boxes at HD or Lowes that handle both for around $80.
 
If you ever have a problem with the 120v line and you get a short the 240v breaker probably wont trip so it is potentially dangerous.

I also did not want to plug it multiple cords but in the end I went with what is to code and was the safest way to go. If my pump shorts out I know the 120v GFCI breaker will trip.

You can buy a mini breaker to put in your panel if you want to split it there, just be sure to use some sort of safetly device on the 120v side.

I went the simple route and used 2 cords since I wanted a 120v outlet by the brewery anyways.

dscn3043.jpg
 
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