Theories about tripping breaker?

[dwellselectric]

I got a call from a friends father last night. He told me that when he opened his summer house this year the breaker for the hot water was tripped. This was last week and of course he reset the breaker and all was fine. Well turns out friday the reset button in the hot water tank was tripped and he had to reset that. All was good until last night when the breaker tripped again. The problem is of course this house is in the middle of nothing. So I didn't know if anyone had any theories about when the breaker would be tripping? The service is just about new to the house so I doubt the breaker itself is bad and I don't know if the element would be causing it to trip? Any help would be appreciated :smile:

 

[iwire]

My guess?

An element has corroded and is shorting to ground.

Further guessing that they drained the water when they left but did not shut the power off to the water heater first which will quickly smoke an element.

http://www.plumbingsupply.com/element-installation-instructions.html

 

[Pierre C Belarge]

If it is not what Bob mentioned above, then it sounds like a high resistance ground fault to me. The time it takes to open means the voltage and current are traveling on the effective ground fault current path. Which could start a fire, shock someone or kill someone. If you cannot make the trip, it is important someone else makes the service call.

 

[masterinbama]

Could be a bad upper thermostat that allows both elements to come on at the same time.

 

[dwellselectric]

Yeah I will make the trip today and thank you for your fast response

 

[hillbilly1]

I agree with iwire, the heating element has a high resistance fault to ground. The thermostat breaks only one leg, so a fault to ground will continue to heat the water until the thermal limit (the button that was reset) trips and disconnects both legs.

 

[Brian Oshman]

How old is the tank? Might just consider replacing the whole tank if it is over 5 years, especially if the place is empty most of the time. Consider a tank less heater. It won't need draining and can just be shut off when closing up the house. Draining the water in a tank so it doesn't go stagnant will allow the inside to corrode quicker since it exposes the inside to oxygen and shorten its life. I know it is glass lined but that is not a perfect process otherwise tanks would never fail.

If you have hard or low pH water without correction then it may be even more difficult to salvage the old tank with new elements as corrosion will have set in. $300-$400 bucks is cheap insurance to the alternative of thousands of dollars in damage from a rupture or ground fault fire in an unsupervised home.

 

[don_resqcapt19]

I would be looking at the water heater temperature controls. I think that the reset on the heater is to clear an over temperature condition. I would be looking for a control failure that lets both heating elements be on at the same time, assuming this is a dual element heater.

 

[peter d]

I encountered this very same problem a few months ago. The solution was to replace the water heater entirely, because it was starting to leak anyway.

 

[electricalperson]

i had a problem like this before. somebody turned on the water heater before they filled it with water and one of the elements was split open like an overcooked hotdog. replaced it with a new element and worked like new

they kept having to reset the thermostat but hte breaker never tripped

measure resistance of the element with a meter. the burned element had crazy readings in the megaohms. i dont remember what a good element says but it says a regular ohm value

 

[Cow]

measure resistance of the element with a meter. the burned element had crazy readings in the megaohms. i dont remember what a good element says but it says a regular ohm value

Basic Ohms law

R=E(squared)/P
R=240x240/4500
=roughly 12.8 ohms

 

[electricalperson]

Basic Ohms law

R=E(squared)/P
R=240x240/4500
=roughly 12.8 ohms

yup thats right. didnt remember the wattage of the heater

 

[dwellselectric]

Okay so interesting problem with the water tank. So I check the top element and I have 240volts across and remove one wire to test the element and all seems fine. Well the bottom element I have 120volts on one leg and nothing on the other leg. Could the t stat on that element be bad?

 

[480sparky]

Why did you remove one wire? To test what?

 

[dwellselectric]

And another question does anyone know if the t stats in the water tank are universal? The water tank is a kenmore power mister 5

 

[480sparky]

And another question does anyone know if the t stats in the water tank are universal? The water tank is a kenmore power mister 5

I'm no plumber, but I don't think there's too many varieties down at the hardware store.

 

[dwellselectric]

I'm no plumber, but I don't think there's too many varieties down at the hardware store.

Yeah I'm going to call the local plumbing store tomorrow but I just didnt know if there was a different one for each hot water tank or if they all fit.

 

[480sparky]

Yeah I'm going to call the local plumbing store tomorrow but I just didnt know if there was a different one for each hot water tank or if they all fit.

I'm sure there's different ones, because there's different sizes of water heaters... 20 gal, 30 gal, 40 gal, 52 gal. etc.

 

[dwellselectric]

I'm sure there's different ones, because there's different sizes of water heaters... 20 gal, 30 gal, 40 gal, 52 gal. etc.

very true. Do you know if they can be changed without removing the element? Just curious becuse I've changed elements before but not the t stat

 

[480sparky]

very true. Do you know if they can be changed without removing the element? Just curious becuse I've changed elements before but not the t stat

I don't see why not. The stat is just a control.... there should be (factory) wiring between them and the elements.

Replacement shouldn't be that difficult. After all, if a plumber can do it......