Geyser trips when hot

[joshthejew]

Hi guys.
Had a problem with a 200L geyser that trips randomly, but the water is hot.

It has a solar PC board and panels, aswell as an eskom supply. I replaced the element and corroded thermostat and the amps were good for a 3kw element. but two days later they phone and say it still trips the cb randomly. Not the E/L

[wynn]

Hi Josh, it must be a Zionist conspiracy, maybe MS will be able to assist you?? LOL

The electricians on TFSA will help you by explaining how it is probably your trip switch on the DB that is overloading when the element switches on

[joshthejew]

I checked. 12,8 amps. The cb is a 20amp so I don't think it's that unless it's faulty. But dont think it's that cause it doesn't trip on startup. Will stay up for a few hours or days until it trips. Can't take that chance cause I have to charge them 100km a trip. Not cheap.

[gobbleteller]

If I may ask, what was the reason you replaced the element in the first place? The reason I ask is that if the CB was tripping earlier because of overload conditions, the excess heat could have damaged the bi-metal strip inside and then it must be replaced.

CB's trip either when there is an overload, or a short circuit between live and neutral. If the element is pulling only 12.8A, neither faults appear to be the cause of the nuisance tripping.

Does the CB only supply the geyser, or is there another load connected?

Good luck with the fault finding

[Leecatt]

I had the same problem a short while ago. It turned out the owner was turning the circuit breaker off during the day and on again in the evening to save electricity. This continuous on off motion damaged the circuit breaker especially when it was turned on under load. Eventually it failed and would trip occasionally. I replaced the circuit breaker and the problem went away.

[Justloadit]

It turned out the owner was turning the circuit breaker off during the day and on again in the evening to save electricity.

Many people are doing this, so I would go for a worn out breaker. I was looking at Chint breaker specs recently, and they reckon that 20,00 mechanical switching is their specified rate and 4,000 electrical life. The specs did not mention about the load being connected. Not knowing the make of the CB, adding the switching the 'On or OFF' under load, may derate the specific breaker in the DB, but then again the geyser is a resistive load, so arcing should be a minimum.

If there is a rise in temperature within the breaker, then it also trips. This temperature could be cause by burnt contacts.

[AndyD]

Firstly there's a possibility it's not tripping the E/Leakage breaker because it's not supplied by it. Did you do an IR test? I assume not because you didn't mention it. If the geyser has some kinda control board then IR test at 250v or disconnect the circuit at the DB and connect the L+N together and IR test at 1000v to earth. Please let me know the results.

Also out of interest why was the thermostat corroded? If there's a leak then that may be your answer as well.

[joshthejew]

Thanks guys for the info. It is a Chint CB but still not totally convinced that it will be that to clear the problem. And as i said before, i dont want to take the risk of having another call back so far away. Yes sorry Andy, will disconnect the L and N, put them together and IR test between them and earth. will also check the isolator for burnt contacts. there was no leaking. the thermostat was corroded due to our poor water, a usual accurrance.

[joshthejew]

Yes it is through earth leakage.

[bergie]

what about the solar panel side of it? could the earth leakage be there?

[Leecatt]

No, then the sun would trip!
Sorry couldn't resist that..... I haven't a clue how solar panels work or if they're even part of the electrical installation, I never thought that they were.
I wouldn't mind if someone would tell a little more about solar panels

[bergie]

ha ha, i'm not so sure myself,but he said something about a solar pc board

[AndyD]

I might be wrong but I assumed the solar PC board was to control a valve that allows water through the vacuum tubes in the panel when it's hot from the sun and closes the water flow when the panel goes cold at night. I have seen systems where excess power generation from PV panels is used to heat the water cylinder but I don't think they use that system in this country yet. It might help if we could get a make and model for the geyser and solar system.

[msmoorad]

as flattered as i am that my opinion is so highly regarded on this forum, i dont know much about solar geysers
and the causes for the problem, that i would have suggested, have already been addressed.

[Sparks]

This post has gone quiet without the reason for the problem. I wonder what the cause was. My first thought was the element. If it had a hairline crack forming it would still warm the water until the crack opened enough to allow excessive enough current through the water to cause the CB to trip. As the water cooled it will close the crack and be ready to warm the water again until the crack opened enough to trip it again. The electrical backup should not be going through the solar circuitry, thus a fault there would just mean that it would be permanently on electrical supply. A 200L geyser should not have such a small element so by the reading you are getting i am wondering, is your element to small and has started to burst open or on the other hand, if the element is the right size then it has definitely started to go because the reading is too low. If you used a clamp meter to test the amperage clamp it over both live and neutral, if you get a reading you know how much current is flowing through the water. Get a new element. If you have a non-contact tester you can just hold it against the copper pipes near the geyser, if it says it is live you will also know it is the element. Just because taps don't "tingle" does not mean that this is not possible, it just means that the earthing is good.


I see now you did say 3kW element, that amperage is too low for 3kW, you were given a faulty element.