Double immersion

PRETEND SPARKS · Mar 29, 2014

Hi guys wonder if anyone come across this one, got called to a cylinder with two 3kw elements in it, both fed from a 32a
breaker to two fused spurs with 13a protection. The shop owner says that one of the spurs banged and after this
neither element now works. Firstly thought that the supply was adequate and secondly can't understand both now not working??? Any ideas anyone. The cylinder is made by joule.

NickD · Mar 29, 2014

PRETEND SPARKS said:
Again thanx for comments however, I wasn't asking for you guys to tell me the resistance readings as obviously this is impossible it was a quick question to see if, for example some one had had problems with the cylinder elements before which was a common fault. I obviously posted my Q while not on the job but the message I got was-: we have got a major incident here the immersion has blown up so yea I was fast in my feet to get to job and consequently didn't take meter Also was the first post or Q I have posted ........

I have a basic baby mutleymeter in my standard toolbox along with my basic kit, screwdrivers etc. I am well aware of the argument about them being not suitable for voltage detection for safe isolation, probes not safe for live, risk of shorts on amperage range, etc. etc. and don't disagree. This is not to say it isn't a useful tool though (bit like a knife really, just cos you can cut your throat with it doesn't mean don't have one), and it's always to hand.

MDJ · Mar 29, 2014

Engineer54 said:
Not having much knowledge of present day off peak economy systems available in the UK these day's. But don't such systems still have a ''boost'' facility, that can be operated out of off peak times??

Basically the clocks usually have 2 supplies, one on peak and one off peak, both immersions are wired to this single clock, the off peak side will only energise when the meter gets switched on the lower tarrif which is usually after midnight. During the day you can press a boost button but the supply is from the on peak side, the lower immersion on the tank is usually the off peak and that gets heated during the night at the cheap rate, the upper immersion is the on peak and the boost when pressed just reheats already warm water which was heated from the night. Also as mentioned by Nick there are different timeclocks, the one I have mentioned is used quite a lot in council flats and houses around Glos.

MDJ · Mar 29, 2014

PRETEND SPARKS said:
Hi guys wonder if anyone come across this one, got called to a cylinder with two 3kw elements in it, both fed from a 32a
breaker to two fused spurs with 13a protection. The shop owner says that one of the spurs banged and after this
neither element now works. Firstly thought that the supply was adequate and secondly can't understand both now not working??? Any ideas anyone. The cylinder is made by joule.

Another Guess but probably unlikely is the bang blew the MCB, you will need to check with voltage testers a supply is coming from the MCB.

NickD · Mar 29, 2014

MDJ said:
Basically the clocks usually have 2 supplies, one on peak and one off peak, both immersions are wired to this single clock, the off peak side will only energise when the meter gets switched on the lower tarrif which is usually after midnight. During the day you can press a boost button but the supply is from the on peak side, the lower immersion on the tank is usually the off peak and that gets heated during the night at the cheap rate, the upper immersion is the on peak and the boost when pressed just reheats already warm water which was heated from the night. Also as mentioned by Nick there are different timeclocks, the one I have mentioned is used quite a lot in council flats and houses around Glos.

Don't believe that's quite the case - I believe the boost button just tells the timer switch to pretend it's 3am or whatever for the next X minutes (or until overriden), and energise the Economy 7 tail(s). Which means your storage heaters, nighttime immersion heater etc. get supplied as if it's the middle of the night. (It's a handy way to Ze test an Economy 7 board without bodging or making assumptions IMHO.)

- - - Updated - - -

The bang could have been an immersion element blowing out and failing.

NickD · Mar 29, 2014

NickD said:
It's a handy way to Ze test an Economy 7 board without bodging or making assumptions.

Or to help ensure you've safe isolated it, just to open an entirely different can of worms.

MDJ · Mar 29, 2014

NickD said:
Don't believe that's quite the case - I believe the boost button just tells the timer switch to pretend it's 3am or whatever for the next X minutes (or until overriden), and energise the Economy 7 tail(s). Which means your storage heaters, nighttime immersion heater etc. get supplied as if it's the middle of the night. (It's a handy way to Ze test an Economy 7 board without bodging or making assumptions IMHO.)

- - - Updated - - -

The bang could have been an immersion element blowing out and failing.

It is the case on the clock I am referring to Nick, it takes 2 supplies from 2 different sources and the boost only works from the on peak, the off peak is for heating the whole tank from the lower element at night. I am not for one minute suggesting what you have mentioned isn't the case either, but probably a different method of wiring and design.

GMES · Mar 29, 2014

Marvo said:
Why would you go to a fault without test equipment? If you can't tell us test results then the best you're going to get is guesswork and speculation.

Marvo now you see what we have to put up with lol

GMES · Mar 29, 2014

MDJ said:
Sounds like the one element is off peak, so unless the op stands by it with his volt stick until after midnight due to the lack of test kit he will never know lol

But at least if he as his voltstick, then he can put it to it's proper use which is to stir is coffee, which will keep him awake till after midnight

GMES · Mar 29, 2014

On a serious note though before the tree huggers jump on me for being flippant.
My set up in van at all times genuinley are;
at least 1 of 2 mft's
2 digital multimeters
1 analogue multimeter to show the digital ones to stop being pansies ( there is no voltage )
2 metrel combi checks voltage testers
1 200amp clamp
1 400amp clamp
1 x 2000amp clamp
2 socket n see
No excuses, yes i am like the terminator of the electrical world.

NickD · Mar 29, 2014

GMES said:
On a serious note though before the tree huggers jump on me for being flippant.
My set up in van at all times genuinley are;
at least 1 of 2 mft's
2 digital multimeters
1 analogue multimeter to show the digital ones to stop being pansies ( there is no voltage )
2 metrel combi checks voltage testers
1 200amp clamp
1 400amp clamp
1 x 2000amp clamp
2 socket n see
No excuses, yes i am like the terminator of the electrical world.

Good to know. Where do you park your van, what time are you usually asleep by, and is there much CCTV around?

GMES · Mar 29, 2014

NickD said:
Good to know. Where do you park your van, what time are you usually asleep by, and is there much CCTV around?

No But there is an 8 stone security system in the cab, see avator for said system.

MDJ · Mar 29, 2014

GMES said:
On a serious note though before the tree huggers jump on me for being flippant.
My set up in van at all times genuinley are;
at least 1 of 2 mft's
2 digital multimeters
1 analogue multimeter to show the digital ones to stop being pansies ( there is no voltage )
2 metrel combi checks voltage testers
1 200amp clamp
1 400amp clamp
1 x 2000amp clamp
2 socket n see
No excuses, yes i am like the terminator of the electrical world.

LMFAO, similar to myself, I carry a multi meter, a MFT, 2 sets of voltage testers, and a analogue Insulation Resistance tester, oh and a socket polarity tester of course, as well as Spare mcbs, spare lamps, all types of bits of cable, a few sockets and switches, I don't like to get caught out if on the odd occassion I get a late call out.

GMES · Mar 29, 2014

So that's 2 of us mike that do it right, i can see this turning into a battle of the van contents Lets wait and see lol.
Ps i also have extra test kit in house as a back up, but i agree with you 100% Mike i dont want to be caught out on the job.

MDJ · Mar 29, 2014

GMES said:
So that's 2 of us mike that do it right, i can see this turning into a battle of the van contents Lets wait and see lol.
Ps i also have extra test kit in house as a back up, but i agree with you 100% Mike i dont want to be caught out on the job.

I won't win what I mentioned is about it, I have more kit as a back up if needed and can also call guys in to help, but a selection of testers as you pointed out should be standard on any Electricians van. It is like connecting a socket up without a screw driver otherwise, just silly to go to a call out without testers.

GMES · Mar 29, 2014

MDJ said:
I won't win what I mentioned is about it, I have more kit as a back up if needed and can also call guys in to help, but a selection of testers as you pointed out should be standard on any Electricians van.

Agreed, you haven't got a chance tosolve a problem without it in my opinion ansd to solely turn up with a voltstick, then you may as well turn up with a Cucumber