Totally stumped. Night Storage Heater tripping out MCB, but ok on daytime circuit.

[Steve Poulton]

Please help. I have a basic understanding of electirics, but 5 Electricians are stumped and I don't know where to go next. My mother in law heats her house by 4 Night Storage Heaters, all of which are wired to a Economy 7 supply/fuse board, with no RCD just MCB. The largest of the Night Storage Heaters began to fail and trip the MCD. To cut a long story short, she ended up having a new one fitted. Unfortunately this new one also now trips the MCB. The electricians have tried swapping the various supplies to the various heaters around in the E7 fuse board and the same heater is tripping the different MCB. It would be an obvious thing to consider that there is a fault on the circuit between the board and the night storage heater. However, they have now wired it into the day time board and it is not tripping. Has anyone got any ideas as we need to get it wired back into the E7 circuit??

 

[buzzlightyear]

Originally the cable feeding the heater was down to earth.

please explain?

 

[elsparko]

heater
circuit
mcb

one of these is the problem, im not being paid to solve this particular problem either, get enough of that through the day to be doing it for free at night

 

[LT21]

I have Never heard so much nonsense in 20 years of being a spark you have not listened to Steve at all

1 circuit only trips on E7 board regardless of what MCB is used in it

2 same circuit same heater same switch works fine on RCD protected board with same size MCB

3 fault must be on E7 board as this is the only thing being swapped

4 Is the heater the biggest and furthest away from board

5 if so possible voltage drop throughout night causing heater to pull more current to rise more amps pulled MCB trips

6 or loose connection on incoming supply also resulting in more amps MCB trips

 

[buzzlightyear]

how did you know his name is steve ?

 

[elsparko]

please explain?

how did you know his name is steve ?

boyfriends i assume

 

[buzzlightyear]

must have been one of the five sparks that work on that job !

 

[elsparko]

are these new members the 5 sparks that cant fault find we have "listened to steve" but the posts are barely readable

 

[elsparko]

if i hired a tradesmen and had to beg the internet to solve the problem id not be paying the original tradesmen!

 

[buzzlightyear]

I am now waiting for curly Larry and mo, the other three stooges .

 

[Wilko]

... tripped as soon as on 20a mcb in E7 board. I have now connected it into a 16a fuse in the fuseboard which is not E7 and it ha been on for 2 days without tripping...

Hi Deakon, interesting fault and it will be great to hear what it was when it's found .
Just my 20p worth - if a 20A MCB trips quickly you are seeing perhaps 50 - 100A current draw and this cant occur without a fault downstream of the MCB - clamp the feed and see what's watt.

 

[elsparko]

were forgetting theres some poor wifey sitting with no heating due to incompetence

 

[AJshep]

Fault must be on the E7 board... So why did you change the storage heater for Steve's mum ?
Look mate it's an easy fault to find. All we know about the E7 board is it has 15 amp mcbs. We don't know if they are type 1 2 or 3

Normal board had RCD so we can guess that the mcbs are more likely to be 16 amp type b mcbs different characteristics.


If I were you I'd be embarrassed you changed a storage heater that didn't need changing, (you could of used ohms law) and your customer or collage has come on here for advice.

 

[SparkyChick]

Ignoring the opening to your post, which I'm assuming was directed at everyone on here who has been making suggestions, asking questions etc. trying to help.

5 if so possible voltage drop throughout night causing heater to pull more current to rise more amps pulled MCB trips

6 or loose connection on incoming supply also resulting in more amps MCB trips

I think you need to review Ohms law. For a fixed resistance, as voltage goes down, so too does the current flowing in that fixed resistance.

As the heater is likely to be a purely resistive load, at 240v, a 15 ohm element will draw 16 amps, at 220v, that same element will draw 14.66 amps. The only way voltage fluctuations will cause increased current to flow in a resistive load is if the voltage rises.

 

[LT21]

His name is on top of his post are you TWP
Boyfriend how old are you grow up
Yes I know Deakon he told me about the problem
He is a young chap trying his best its not 5 sparks it he’s been back 5 different times trying to solve problem and one other has been
He doesn’t need clowns like you giving him stick he doesn’t want you to fix it he was just looking for some guidance

 

[buzzlightyear]

so how many Steves are up to press?