faulty immersion heater

[Dylanmaintenancematters]

Hello,
I have a faulty immersion heater, the element is a new one I fitted after this fault showed but still the problem persists.I used a neon to check for power supply????Having read some of the pref posts on this forum,I used a multi meter.But unsure of how to check the voltage.I have still got a reading on testing the ohm through the thermostat at the lowest heat setting ,so think it could be the thermostat.The element testing though the N to the cylinder and the L the same,I have no reading.
would I get a lit up neon if there was no power?
I did first of all try using a neon and it did light up regardless of what i touched,on both sides of the thermostat ,the L and the N and even the top of the element housing,but after reading the forum I have discounted the readings hearing about their unreliability.would a faulty thermostat cause the RCD on the consumer unit to trip soon after being reset?
as far as I know no nails or new screws have damaged cables.
I cant understand why this problem would have just appeared after being fine for years.
PLEASE does any one have any ideas that might help me.

 

[ericmark]

A neon screwdriver can alert one when a mistake has been made but is of very little use for testing.

We need to measure between two points the neon screwdriver measures between a large mass (your body) through a resistor and clip and the blade and your body is not really a reliable point to measure against.

There are neons with two leads often four neons each designed to light at a different voltage and the leads are fused and have the required finger guards.

There are three parts to most immersion heaters. The element, the thermostat, and the cut out the latter may be where one has a metal or special plastic tank resetable but where you have a light plastic tank often non resetable and you have to fit a new one which comes combined with thermostat.

As well as the electric danger there is also a danger if wrongly wired of over heating the water which can in turn cause the light plastic tanks to fail there has been a well documented case of a baby which died as a result of the boiling water coming through ceiling.

You seem to be lacking the skills required and I would say you would likely be better to get some one who has the skills to do the job.

 

[Dylanmaintenancematters]

I just dont know how to use a multi meter,I live off grid and have a diesel generator and inverter with 12x2V deep cycle battery set at 24V, I am quite capable and have in fact built the whole system my self from scratch,the main output from my genny which is 10 KVA is 32A and goes through to the main consumer unit and change over switches, so I can bypass my sensitive inverter if In ever need to use heavy equipment e.g grinders and heavy tools, I also have another change over switch for switching to two other standby genny's that are much smaller. The second output on my main machine is a 16A and does not go through my inverter,this is going to a smaller consumer unit and to my immersion heater on 2.5mm cabling, so I have hot water when ever the generator set is on.
This system has been working very well for three years until a few days ago.when the thermal protection on the 16A output was not staying on.I found that there may be a problem with the immersion it's self so I changed it.on looking at the immersion I removed, it had allot of blackening as if it had got way to hot and I thought it must have failed.But the new one is also not working.on using a neon it seemed I was getting power through to the immersion. I read how to check the immersion from the forum using a multi meter and checked the L to the cylinder and had no reading from the ohm setting,I also did the same from the N and had the same and on the thermostat I had a low reading on the high setting and on the lowest being at 40 degrees it was 001 also?
may be its the small consumer unit that is the problem?I have an RCD rated 63A and the immersion MCB is rated at 16A.Am I pushing it coming out of a 16A output on the genni for the immersion heater? its been ok for three years?
Any one?????

 

[Dylanmaintenancematters]

my under standing of the fusing of an immersion is that a fused switch is 13A.My generator is 10KVA it actually has an 18 KVA alternator so it can never be over loaded,the genny would stall first, as it runs at 1500 RPM.It has two outputs a 32A and a16A,it also has another which is 110V plug being the round yellow,but it is not needed.My generator powers a 3000w pure sinewave inverter and it has been recomended that for my 600AH batteries I charge at 90A MAX.
But the out puts, as on any commercial generator has the large 32A round plug and the smaller 16A round plug as separate outputs.How is it that you can charge at 90A through a 32A output?
is it just that the 32A and 16A is the sized plug that is referred to?????

 

[Dylanmaintenancematters]

I need to add that the smaller consumer unit is fed by a 4mm armoured cable,and then 2.5 to the immersion,and that it is a copper cylinder which is an indirect (it has a coil for hot water from an Arga with back boiler).
thanks!