No power to the wiring centre!

[Savva]

I went to a job (y-plan system) where all the stats, motorised valve & the 2 channel prog were dead. The wiring centre was dead too but the spur (where the wiring centre took its perm live) was live giving 235v. I had to leave without fixing it. Anyone had this before? Any advice on what I could have done to diagnose the fault? Cheers guys.

 

[gassafe]

Faulty spur or blown 3 amp fuse?

 

[c.gas]

Had a friend last week who said he turned off a boiler at the fuse spur but then it didn't work after that, turned out he had to replace the fuse spur as apparently that was faulty. Not come across it myself as of yet tho

 

[turnpin]

Was the wiring center the PCB type if so maybe an internal fuse had blown......regards Turnpin:smile5:

 

[Savva]

Cheer guys, I wish it was as simple as a blown fuse. What really puzzled me was the spur was fine, I had 230v going in and then 230v coming out when the switch was on but then nothing in the wiring centre! It was a normal wiring centre, didn't catch the make...

 

[SimonG]

Cables goosed?

 

[SimonG]

Had it with a boiler. Flex ran over flue on an external grant. Cable melted together.

 

[bigman]

Is there an isolator between the spur and the wiring centre maybe hidden behind something near the boiler or airing cupboard?

 

[Savva]

Checked, couldn't find anything. I thought there might be another spur somewhere but there wasn't anything I could find! Very frustrating because if I could get power to the wiring centre I'm sure everything would have worked.

 

[gassafe]

Cheer guys, I wish it was as simple as a blown fuse. What really puzzled me was the spur was fine, I had 230v going in and then 230v coming out when the switch was on but then nothing in the wiring centre! It was a normal wiring centre, didn't catch the make...

What goes in must come out... Damaged cable I guess

 

[c.gas]

Have you got a volt pen, that could help you to a degree, I know there not the best tool but can be helpful

 

[Worcester]

We had one that totally confused us for about 5 mins, usuall fault finding process and we discovered that someone had reversed live and neutral half way round the ring main....

So neutral was live at 230V and live was neutral at 0V, old "mechanical" controls worked fine...

 

[jtsplumbing]

Do you know how to check if the cable damaged using a multi-meter ?

 

[SimonG]

Length of flex with three pin on the end wired into wiring center.

Not wired through programmer?

 

[1Steven]

Do a continuity test on the cable from the spur to the wiring centre.

 

[Jay The Plumber]

you may find that the cable exiting the fused spur is clamped onto the insulation.. meaning that you read voltage at the screw to the load side of the spur but the cable isnt getting any juice.
OR - sometimes the cable coming from the spur is badly clamped or the wrong side of the captive U and is barely in contact with the load side meaning it cant supply enough juice to the few strands that may be in contact..
ive seen both these things happen

 

[1Steven]

Hello Frank!

 

[Jay The Plumber]

Hello Frank!

this is awesome, 70 posts in and I already have my own nickname !

:hurray: :hurray:

 

[1Steven]

Well if you don't ask you don't get! :21:

 

[Robert Tyrrell]

I've got a similar problem to this. I went to fit a new programmer and 'tidy' the wiring for a guy who'd had one of those Danfoss 3060 mechanical programmers (Fitting a new Honeywell) and everything was working, kind of, until I finished the rewire and switched back on
Power at the spur but not at the 10 way. I've tried everything I can think of so pray do tell - how does one check for reversed L & N?
I know how to do the continuity check but reversed L & N check is new to me.

btw: I say that it was 'kinda' working beforehand because that what it was. every time the heating was on, the water was on as well. There appeared to be no interlock on the HW circuit. One 28 mm MV and that's it. I determined that it must be wired as a C plan as a result of what I found/observed.
It doesn't help that the builder who put up the extension didn't match up the cables either. Grey T&E onto (I think) white flex from the stats.
I was working until 7:30 trying to sort this before the guy told me to go home and have a sleep on it I'm back tomorrow afternoon to try again.

 

[Jay The Plumber]

have you found 230v in the wiring centre at all?
just put the black probe on a good earth and then probe the other connections for the live.. when the meter reads 230, the wire you have the red probe on is live..

usually the 10 way has the first 3 connections as L-N-PE

 

[Robert Tyrrell]

have you found 230v in the wiring centre at all?
just put the black probe on a good earth and then probe the other connections for the live.. when the meter reads 230, the wire you have the red probe on is live..

usually the 10 way has the first 3 connections as L-N-PE

Yep - thanks very much for that info, thats what I was doing. I just couldn't remember the results from yesterday, hence the question.
What I really wanted to know though, for future reference, is how to determine if the L&N are reversed?
I'm back there this afternoon and I'd like to get it sorted in time to get home for the rugby at 1:30 (Being of Irish roots and all that )
I'd also like to know (or be reminded if it's what I'm doing already) of how to find the other end of the room stat or cylinder stat cable where it pokes out of the wall?
Cheers for the help

 

[Jay The Plumber]

do you mean to see if the power supply wires are reversed ?
on my meter, if you swap the probes around they will read -230v AC

I dont know what you mean by find the other end of the room/cyl stat cable.
when wiring has been messed with by owner/builder etc I usually just do a continuity test and turn the stats on and off.

 

[Robert Tyrrell]

Right, I might have found the problem but I'm not certain - yet.
When I put my fluke tester into the blue wires, either of them, coming from the sich motor on the move, and the PE on the 10 way, I have continuity so I'm thinking that the motor might have given up in the first place

 

[REDSAW]

could be the contact plates on the spur arched out?
change spur & cable and start there before you get in a carfuffle

 

[Robert Tyrrell]

could be the contact plates on the spur

I ain't no cowboy ya know
Lit wasn't the synch motor btw. I noticed a missing link, which is what I felt like until I realised that there was talk link before.