Under-performing circuit panel with two 240V appliances

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RodrigoDC

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I have an electrical problem that's driving me nuts.

I have only two appliances that require 240V lines in a small Cabin in the woods. Both appliances, as well as all other electrical outlets and switches, were working fine just a few days ago. I showed up the other day, turn the circuit panel main breaker on (as I normally turn it off when leaving the cabin), turn the breakers on to the 240V appliances (a water heater and a range), and neither one works.

Each appliance is connected using a single 10-gauge line to a 240V, 50 amp breaker respectively. The lines are easy to follow under the cabin and I verified that they are in good condition and independent. I even replaced the water heater breaker with a spare 240V 40 amp one to no avail. I further changed the position of the breakers to make sure; heck, I even took ALL breakers out of the panel and left exclusively the water heater on, and still no go.

This is a simple configuration on a 8-year-old, 150 amp panel with relatively few breakers attached, namely the above two appliances (2 50-amps), bedroom lights, living room lights, kitchen lights/refrigerator, and outside lights (all 15 amps), and a 20 amp water pump breaker. That's it!

I witnessed three issues that were completely illogical to me:

  1. Both 240V appliances were receiving some current because the oven's small LED light would turn on red when turning the oven on, but the heating elements or the top stove would not work or heat up at all.
  2. The water heater green, stand-by LED would ONLY turn itself on when the kitchen light was turned on. Remember, I verified about 5 times that the water heater had its own, independent circuit to the panel; there was absolutely no reason whatsoever why this was happening. Upon disconnecting the kitchen 15 amp breaker from the panel, the water heater green LED would no longer turn itself on (of course). However, there was still some current being received by the water heater because I tested it. Unfortunately, I did not have a multimeter with me, but being resourceful, I stripped the wires off an old bulb socket, and proceeded to verify that each hot on the water heater was getting some electricity. However, one wire was providing intense light (as you would expect), but the other one was outputting a very dim light. So obviously, the appliance as not getting the entire 240V current to make it work, although I cannot say what the exact voltage reading was until I return with a multimeter.
  3. Finally, the kitchen breaker was also under-performing, that is, the kitchen light was flickering and the small fridge would turn itself on for just a few seconds. When I moved the kitchen breaker to a different location within the panel, the problem disappeared, that is, the fridge began working just fine, and the lights were at full strength. What's even weirder is that when the breaker was in its new position, the water heater LED would NO longer turn itself on when turning the kitchen light.

I checked the circuit breaker panel and there was no sign of corrosion or water leakage, just some dust and a few insect nests.

My questions are as follows:

  1. Why would the 240V appliances not be receiving enough juice? If all other lights and small appliances work fine, why not these two in particular?
  2. How in the world did the kitchen lights turn the water heater LED light on if they have completely independent circuits?
  3. Is it possible at all at the circuit breaker panel be damaged? That is, could it be that the panel itself be transferring electricity from one breaker slot (kitchen) to the other (water heater), hence enabling the kitchen to send some electricity to the water heater via the panel?
  4. Am I seeing ghosts?

Any insight would be greatly appreciated before I pulled my last hair out.

Thank you!
Rodrigo
 

Reach4

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You could have an open in one of the hot lines coming to the breaker. This could even be outside of the building. Some of the low power you see could be because power from the active leg is feeding through the 240 VAC appliances to the dead leg. If you turnoff the two 240 breakers, you might find that some of your 120 V outlets are dead.
 

RodrigoDC

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Thanks for your reply. But then, why was it working just fine a few days ago? Also, If I have an open, would it not be too much coincidence they would occur on both 240V appliances?

You're right, I did not test all plugs, but remember, I took off all breakers except the one for the water heater, and it did not work but was under-powered. I did disconnect the water heater and left the other ones on, and they all worked (lights, refrigerator, albeit after moving the breaker, etc.), except the for the 240V range.

Does that make sense?
 

Reach4

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Given that the 120 V outlets work even if the water heater breaker is off, my open leg hypothesis does not hold up unless the range burners or oven were on. But such an open of the power to one of the buses in the breaker box, that would affect both 240 V loads and more. But there could still be some voltages running around-- some of which would be reduced from normal.

Regarding the LED on the water heater, lighting an LED does not take much voltage. I don't know if the AC gets a neutral wire or not.

I would pull the cover off of the breaker, and check voltages. Measuring the voltage from hot leg to hot leg. Should be 240 V. Measure voltages to neutral. All hots should be 120 V to neutral.

"But then, why was it working just fine a few days ago?" That question surprises me. Maybe you shouldn't pull the cover off of that breaker panel.
 

RodrigoDC

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Reach4, I believe you misunderstood me. If I lost a leg, which is what you suggested, then all would make sense. What I meant to say when I stated that all was working fine a few days ago, is because I was unaware that legs can be lost, since it has never happened to me, and while it occurs, it not the number one possibility that regular civilians such as myself think of.

At any rate, yes, that appears to be logical, explaining the back feed of lines. Remember, I have two 240V lines. perhaps I never tested a 110V with both 240V breakers disconnected.

I did pull the cover of the panel, but because I did not have a multimeter, I was unable to measure voltage before and after the main breaker or for each hot. Unfortunately, I am not a the cabin and cannot get there tonight. I will try to go first thing in the morning and report back.

If I can prove this is a lost leg, as you suggest, will the POCO fix this a their expense?
 

Jadnashua

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WHen you say one line, I'm assuming that you really mean one cable that contains multiple conductors? A stove typically uses (new ones anyway) a 4-wire cable - L1, L2, Neutral, Ground. The WH may only need a three wire cable - L1, L2, Ground.

If you lost one leg, neither would work properly and only some of the other 120vac circuits would work.
 

Reach4

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If I can prove this is a lost leg, as you suggest, will the POCO fix this a their expense?
I guess that would depend on where the open occurred. I have heard of them sometimes fixing things that are not officially their problem.

It seems to me that if you have lost a leg on the way to the breaker box, the problem has a good chance of being on their lines. I think the demarcation point is usually at the crimps on the weather head for overhead service.

I am not a pro.
 

RodrigoDC

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Jadnashua, yes, by line, I meant to say circuit cable. Thanks for the clarification. Indeed, neither 240vac appliance works properly, and everything else seems to work fine except for the kitchen, other than when I move the breaker to a different slot on the panel.

Thanks Reach4. I'll report back tomorrow after the poco tech shows up.
 

Speedy Petey

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Also, the #10 wires going to the water heater and range should be on 30A breaker, NOT 40 or 50A.

Who wired this cabin originally?
 

RodrigoDC

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Speedy Pitey, I do not know who may have wired this Cabin as I purchased about 6 months ago and I've been working on restoring it ever since.

I will double check if the wire is a #10. I could be wrong and it is a #8, I'm not an expert. The manual for the water heater does specify that the appliance requires 240V and a 50amp breaker. I won't be able to see it until later today.

Thanks a bunch.
 

DonL

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One thing that can cause 1 leg to be lost, is the main breaker does not completely close both legs.

When the breaker is left in the off / open position the contacts can get corroded, And ants or other small bugs can get in between the contacts and create resistance.

What kind of "insect nests" did you find ?


Good Luck on your project.
 

RodrigoDC

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Good suggestion DonL. I will be able to measure voltage with a multimeter before and after the main breaker when I get there later today.

Thanks.
 

RodrigoDC

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Quick update: I actually went up to the Cabin with an electrician friend of mine. As it turns out, there is full electrical current coming from the POCO drop. However, the left side of the panel is not getting enough voltage. It could be the main breaker, but I may as well replace the circuit panel (150 amp) and the main breaker. This is an safe fix.

Could anyone suggest otherwise?

Also, I was wrong. The circuit going to the WH is actually a #6, but according to the WH specs, I should have a 60amp breaker (instead of the current 50 amp), specially when drawing cold water (this is from an underground cistern), as the WH may pull up to 54 amps to heat up cold H2O. I may as well upgrade it also.

I'll keep you posted when we replace the panel.
 

DonL

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It does sound like the main breaker.

I guess you have a tankless water heater.

Changing the panel out may not be a bad idea, unless the main breaker can be had for cheap, and that is all that is wrong with it.
 

RodrigoDC

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Correct DonL, a Rheem RETE 13 tankless water heater. The 13 means 13 KWs.

Pretty good for a small cabin with no natural gas and difficult to reach propane.
 

Reach4

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However, the left side of the panel is not getting enough voltage. It could be the main breaker, but I may as well replace the circuit panel (150 amp) and the main breaker. This is an safe fix.

If you can detect a problem with the main breaker with an ohmmeter after you have pulled that breaker out, then it would seem certain that the problem is the breaker rather than the panel.

Maybe there are reasons you want to go to another panel anyway.
 

RodrigoDC

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OK, I just want to resolve this post. There was indeed evidence of charred buses on the left leg of the panel. Was that what was causing the problem? I'll never know, but this is a new start, and since I am not always there and other people may use the Cabin from time to time, I prefer to take no chances. The whole thing cost me about $160 with new breakers, and all is working well at the moment, including the 240V appliances.

Thank you all for your wonderful suggestions and guidance. I hope this experience helps other folks.

Rodrigo
 
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