Call out to an Overloaded board

[Robert cooke]

Was called out tonight to this beauty of a job. They’ve been having problems with they’re air source heat pumps, which are fed from a sub main.

Consequently, they have plugged in 7 x 2kw fan heaters to warm the house. Now, the sub main has been fed directly from the top of the rcd (see picture), no mcb to protect it. My thoughts tell me this is a big no no, but the guy will go for the jugular of the guy who fitted it all, so hopefully you will all either agree or disagree before I speak to him tomorrow ?

I need to look further, but I suspect that all the heaters are on circuits on the same rcd, so can we put that much of a catastrophe down to just overload? Surely it should of tripped? It took out the 100a dno before it stopped.

Cheers

 

[Gavin John Hyde]

We are all agreed uts a sh!t storm of a piece of work from whoever installed it. Given that it nearly caused a nightmare scenario i reckon building control and maybe even the police should know... Could be a rare case where somebody gets prosecuted?? Doubt they notified it!!
A nice story in local paper about cowboy electrician and how house nearly caught fire will motivate them into taking action.

 

[telectrix]

I had to take a second look at the photo as never used one of these boards before as usually the supply to the RCD is at the top but in these boards, the supply looks as if it is in the bottom, therefore, the load of this unprotected sub main and the MCB loads are going through the RCD too much current.

pretty sure the RCDs are incoming at top. tails come from bottom of main switch to |RCD top. then busbars bottom of RCDs to bottoms of MCBs. the weird thing with these boards id that the L and N on the main switch are reversed and the busbar has a crank in it to take L to the right.

 

[PEG]

We are all agreed uts a sh!t storm of a piece of work from whoever installed it. Given that it nearly caused a nightmare scenario i reckon building control and maybe even the police should know... Could be a rare case where somebody gets prosecuted?? Doubt they notified it!!
A nice story in local paper about cowboy electrician and how house nearly caught fire will motivate them into taking action.

Really? You didn't call them the other day,when Kentucky FC was shut,did you?

Get the appropriate scheme on it...and they can eventually email a firm missive,recommending that the culprit promises to think about maybe sitting his 2391...

 

[Strima]

Any certification? of course not bloke that did that abortion was probably illiterate, what a mess, bet that stunk the place out, you mention heat pump install, probably another post wonder course installation, Crikey what have we unleashed with all these short courses? I'm biased I know, when it comes to training establishments.

As a Electrical Trainee I completely agree...

It probably did stop a fire Strima. It contained it in the enclosure, the board itself did not ignite.

My comment was tongue in cheek, sarcasm doesn't come across very well on a forum.

 

[Wilko]

pretty sure the RCDs are incoming at top. tails come from bottom of main switch to |RCD top. then busbars bottom of RCDs to bottoms of MCBs. the weird thing with these boards id that the L and N on the main switch are reversed and the busbar has a crank in it to take L to the right.

Yes, that could be right. If so, then RCD didn't have the submain load through it (?). Also, it looks like L and N reversed on the RCD ...

 

[Wilko]

Snowed in here today. Thankful for the Forum

 

[telectrix]

not snowed in here, but job 30 miles away postponed. new build with no windows fitted, no heat, water frozen, -10 if you allow for wind chill. sod that for a game of snowballs.

 

[Pete999]

not snowed in here, but job 30 miles away postponed. new build with no windows fitted, no heat, water frozen, -10 if you allow for wind chill. sod that for a game of snowballs.

Go on Tel if you have had yer flu jab you'll be OK

 

[telectrix]

no flujab for me. got enough problems without letting them quacks loose with their stabbers. never know what they're sticking in you. at least with beer, you know what you're putting in your body.

 

[Pete999]

no flujab for me. got enough problems without letting them quacks loose with their stabbers. never know what they're sticking in you. at least with beer, you know what you're putting in your body.

True, very True.

 

[telectrix]

and as for them trying to get me to stop the smokes, i tell them that smoking is beneficial, after all, smoking cures kippers.

 

[Wilko]

It'd need to be a jab of ethylene glycol to do any good I reckon

 

[Des 56]

Very naughty job, the child who did it should be made to sit in the corner

"Bet there was no certification"exclaims the enraged profesionals

Certification my rear end,I think this over hyped often needless function (that happens to swamp our job) makes any difference whatsoever to the standards that are found

 

[SparkyChick]

pretty sure the RCDs are incoming at top. tails come from bottom of main switch to |RCD top. then busbars bottom of RCDs to bottoms of MCBs. the weird thing with these boards id that the L and N on the main switch are reversed and the busbar has a crank in it to take L to the right.

I agree with the original diagnosis... if you look carefully at the RCD on the right in picture 2, the neutral cable comes out and goes up to a neutral bar with circuit connections on it.

The last picture clearly shows the line cable from the top of the RCD to the bottom of the MCBs in the right direction to be a feed to the MCB bus bar.

I've nearly caught myself out on one of that style because of the upside down connections... struck me as being a bit strange at the time. But if you think about it logically, it's somewhat safer that the traditional power in at the top since if you turn the RCD off, all the exposed terminals are dead apart from the main switch. It just means you have more of those jumper cables taking up space.

 

[Strima]

Many moons ago I was living in an MOD house, the next door neighbour was away in sunnier climates with his Mrs stuck at home.

One night she's furiously banging on the door and I answer thinking my lucks in and she's finally come round for the threesome I've been hinting at...

But no, there's a stack load of smoke coming from under the stairs and the 3036 board is smoking away quite nicely. Bakelite really stinks when it gets hot.

Turns out their boiler had gone bang and wouldn't be repaired for a month. The housing manager had given her a couple of old convection heaters to try and keep her and the kids warm, then one RAF welfare officer took pity on her and brought round a couple more thinking he was doing the right thing.

In total she had five of these things chugging away, no wonder the board got a little warm as there was one ring final for the whole property. Those 3036 fuses are really good at hanging on...

These were the old style convection heaters dating from the 60/70's, the one's which were a manky brown and gold colour...