Control Panel Troubleshooting Help?

[TheMerkle]

My diagram, after the E-stop modifications I made, looks like this now:

 

[Ozarks Mountain Brewery]

so it looks like originally you had a 115v power on coil and a 240v estop switch then you changed it , I would work around the estop to rule that out

 

[Stoney315]

I think the problem is more likely a power to power or power to neutral short. If anything were shorted to ground, it should trip the GFCI. GFCI's are designed to trip faster than normal breakers (since people get hurt much quicker than wires, and GFCI's are to protect people, and breakers are to protect wires.)

Brew on

So to check what Doug is saying. Lift the connections coming off point 2. That will eliminate line to line. But this will allow the control power to turn on the main contactor. If you lift line 2 connection and if it still trips you have a line to neutral problem.

 

[doug293cz]

Just to rule out another potential problem: switches and relays dont care about polarity right?

In most cases, "in" vs. "out" doesn't matter for a mechanical switch. If using a double throw switch for selection purposes, then what's connected to what can make a big difference.

Brew on

 

[TheMerkle]

So to check what Doug is saying. Lift the connections coming off point 2. That will eliminate line to line. But this will allow the control power to turn on the main contactor. If you lift line 2 connection and if it still trips you have a line to neutral problem.

Instead of removing all of the line 2 connections, could I just remove the line 2 supply wire where it comes into the box to the same effect? Then, test it that way to rule out hot to hot shorts?

 

[doug293cz]

Instead of removing all of the line 2 connections, could I just remove the line 2 supply wire where it comes into the box to the same effect? Then, test it that way to rule out hot to hot shorts?

Can't hurt to try.

Brew on

 

[Ozarks Mountain Brewery]

so one important question, do you have a 4 wire breaker box with an isolated ground ??

 

[TheMerkle]

so one important question, do you have a 4 wire breaker box with an isolated ground ??

It's the same receptacle I used for the previous box I built. Though, that box box didnt use the neutral leg at all. I'm not sure if that rules out the outlet.

 

[Ozarks Mountain Brewery]

if your fuse/breaker box does not have an isolated ground this design will not work

 

[TheMerkle]

I'll research that right away.

 

[TheMerkle]

Sorry for the newb questions, I hired a professional electrician to handle the subpanel part, lol. Can you tell me exactly what I'm looking for to determine the subpanel's efficacy? Do I need to be checking out the main panel at all?

 

[doug293cz]

With a GFCI breaker, you need a four wire outlet with separate ground and neutral for the GFCI to work properly, if you have any 120V loads in the system. If the system is 240V only, then you don't need the neutral for the GFCI to work properly. Your earlier panel (one of my designs) is 240V only, so would work with a 3-wire plug. Your newer design, with 120V pumps, will not work with a 3-wire plug.

Brew on

 

[doug293cz]

you need to check the main panel , see this panel where the ground and neutral wires are hooked together, this is what I call a 3 wire box, a 4 wire box will separate the copper and white bus bar and the copper will have a wire going into the earth

View attachment 580879

I thought ground and neutral were normally bonded in the main service panel (as in the panel shown.)

Brew on

 

[Ozarks Mountain Brewery]

its a little tricky and in reality they do join at some point but on the post 1975 breaker boxes they have an isolated ground bar that grounds to earth as well as a neutral and ground to outlets, the above box is like mine and will only work with 3 wires, that 4th wire is that ground to earth in the breaker box and the ground fault and sub panel has to use it, you can also wire a ground fault to a 3 wire box but it's wired different

 

[doug293cz]

its a little tricky and in reality they do join at some point but on the post 1975 breaker boxes they have an isolated ground bar that grounds to earth as well as a neutral and ground to outlets, the above box is like mine and will only work with 3 wires, that 4th wire is that ground to earth in the breaker box and the ground fault and sub panel has to use it, you can also wire a ground fault to a 3 wire box but it's wired different

I disagree, I believe you can do a four wire, with or w/o GFCI, in that panel. For no GFCI, the ground and neutral wires both connect to the same bus in the panel. For a GFCI, the load side neutral connects to the neutral terminal on the GFCI breaker, and the GFCI pigtail connects to the common bus, as does the load side ground.

Brew on

 

[Ozarks Mountain Brewery]

the sole purpose of the extra ground is for lightning, yes sure it can be rigged any way to work but it's not a true to code box as of today

 

[TheMerkle]

So, if my main box inside the house has the bonded neutral and ground, and the same is true in the outdoor subpanel where we had a 30a GFCI installed to protect the receptacle we planned to use, that receptacle would properly power the previous appliance but throw the main indoor breaker if connected to the new appliance? If that's so, then would I be able to get the newly built appliance (the PJ design) to be compatible with the outdoor subpanel by driving a new ground pole and rewiring the GFCI accordingly?

For the record, I plan to hire an electrician for this, I just want to try to understand as much about it as I can so that I can meaningfully describe my needs to him.

 

[Ozarks Mountain Brewery]

that's what I did, I pounded a ground rod 8 feet and brought that wire into the breaker box, but just to let you know you change your box wiring just a little and it will work like the old box and save some money

 

[Ozarks Mountain Brewery]

oh and I'm not at all saying this will fix your problem by the way, I would consult your electrician on the difference first

 

[TheMerkle]

How can I change the box wiring to work like the old box? I like saving money lol

 

[TheMerkle]

So, you're saying I could just move the ground lug attached to the appliance enclosure off the ground supply wire and attach them to the line 2 supply wire instead? Am I understanding that right?

Are there advantages to adding an 8 foot ground pole inslead?

 

[doug293cz]

for reference this is a box I made for someone recently, it works with the breaker box I showed above

View attachment 580894

That design has a hard wired ground fault. It's not gonna work with a properly wired GFCI on the supply side of it. And if you modify the GFCI wiring so it will work, you might as well leave the GFCI out altogether, as it will not provide any ground fault protection.

Brew on

 

[doug293cz]

So, you're saying I could just move the ground lug attached to the appliance enclosure off the ground supply wire and attach them to the line 2 supply wire instead? Am I understanding that right?

I'm having a hard time understanding exactly what you are proposing, but if you are saying what I think you are saying, then NO.

Are there advantages to adding an 8 foot ground pole inslead?

Ask you electrician whether or not code requires you to add a secondary ground. That issue is above my pay grade.

Brew on

 

[passedpawn]

Here's two thoughts that should be at the top of the build list:

1. Make sure you have a GFCI
2. Make sure the first thing you do is test the GFCI.

 

[TheMerkle]

I fully understand now that, with the ground and neutral bonded a second time in the outdoor subpanel, the GFCI installed there can't work properly. What I don't understand is why my original electrician would run 4 wires from the house to the garage, and not attach them to separate busses in the subpanel.

This weekend my new electrician should be able to tell me if separating the ground and neutral in the subpanel will require a new ground pole and a fourth bus bar installed outside, or if we just need the fourth bus bar and we can use the ground coming from the main panel.

That should have the GFCI operating correctly, and only then will any further efforts on the new appliance continue. That said, hopefully the GFCI is the only problem with the appliance in the first place

 

[doug293cz]

Let me see if I have your structure wiring correct:

• Your main service panel (the one where the power comes in from the utility) has a 30A, non-GFCI breaker.
• You had a sub-panel added in your brewing area that contains a 30A, GFCI breaker.
• The wiring from your main panel to your sub-panel is 4-wire, fed from the 30A breaker in the main panel.
• Neutral and ground are bonded (connected) together in your main panel.
• Neutral and ground are isolated from each other in your sub-panel.
• There is a 4-wire cable from your sub-panel to your 4-slot outlet.

Is all of the above correct? Is your sub-panel in a separate building from the main panel?

Note: I think I was confused earlier, and thought your first panel was plugged into a 3-slot outlet.

Brew on

 

[TheMerkle]

Let me see if I have your structure wiring correct:

• Your main service panel (the one where the power comes in from the utility) has a 30A, non-GFCI breaker.
• You had a sub-panel added in your brewing area that contains a 30A, GFCI breaker.
• The wiring from your main panel to your sub-panel is 4-wire, fed from the 30A breaker in the main panel.
• Neutral and ground are bonded (connected) together in your main panel.
• Neutral and ground are isolated from each other in your sub-panel.
• There is a 4-wire cable from your sub-panel to your 4-slot outlet.

Is all of the above correct? Is your sub-panel in a separate building from the main panel?

Note: I think I was confused earlier, and thought your first panel was plugged into a 3-slot outlet.

Brew on

Sorry if I was unclear, Doug. Let me see if I can answer all your bulletpoints in order:

• My main service panel, and by "my" I mean my brew partner's, is a 100A service with a (I believe) 60A non GFCI breaker powering the subpanel in the garage, where the brewery is housed.
• We had electrician add a 30A GFCI breaker to the subpanel outside to power the first appliance we built a few year's ago using your design.
• The wire from the 60A breaker in the main panel feeding to the subpanel is four wire, including a bare copper ground.
• With said brew partner out of country, I have access to the garage and brewery, but not to the house. I am assuming that the neutral and ground are bonded in the main panel. It is my understanding that this is required in residential panels where the service comes into the home.
• Neutral and ground are NOT isolated in the subpanel outside. Neutral and ground are bonded at the same bus bar.
• There is a four wire cable from the subpanel 30A GFCI to the 4-slot outlet we used for the previous appliance, and are trying to use again for the new appliance.
• The main panel in the house, and the subpanel in the garage are in separate buildings.
• When building the first appliance, I modified your design and used a 4-prong dryer plug and simply taped up the neutral supply wire and did not use it.

 

[doug293cz]

Thanks for the detailed answers. One thing I am still not sure of: when you turn on the main power switch, is it the 30A GFCI breaker in the sub-panel that is tripping, or the 60A standard breaker in the main panel?

Also, is there any chance that the 60A breaker in the main panel is a GFCI breaker? I ask because having the ground and neutral connected inside the sub-panel would most likely trigger a main panel GFCI to trip.

Since the sub-panel is in a separate building, code may require it to have it's own earth grounding rod. Here is where my knowledge runs out; I don't know exactly what situations require the secondary ground rod.

Brew on

 

[TheMerkle]

When I turn on the main power keyswitch on the appliance, the main panel 60A standard (it's definitely not GFCI) and the subpanel 30A GFCI BOTH trip.

I'm pretty certain that isolating the ground and neutral from one another in the subpanel will resolve my issues, and looking at the relatively low cost of driving a new ground pole, I think I may go ahead and do it whether its required by code or not.

 

[doug293cz]

I still think that there is something more than just the connected ground/neutral in the sub-panel. Isolating them will prevent the GFCI from tripping, but the GFCI tripping should not cause the 60A main panel breaker to trip (when you test a GFCI outlet, the associated panel breaker doesn't trip.)

I think you should test the voltages on your 4-slot, 240V outlet. I'll try to put together a quick drawing of what the voltages should be between each pair of slots.

Brew on