Time clock stopped working

[uksparks]

Hi,

any ideas chaps? Got the time clock below, was working fine 12 months ago before works started, just gone to power up and am getting no voltage on the output, wound it up etc...

 

[uksparks]

Off peak supply, why else would it be controlled by a DNO timeswitch?

Yeah it has a mid afternoon boost for a couple go hours too. Oh it Los feeds the immersion, which iincidentally I have put in a change over switch so that you can switch between the economy 7 board and the 24 hour board.

 

[Simlec]

So if you have a fault on any one of the circuits, you would lose all the heating !

 

[uksparks]

No, because you could turn the circuit off... Well unless it was an earth fault then I will pop over and sort it as thats what i exist for... I did not want to be splashing out on 12 RCBOs as was trying to keep the cost down, I accept what you are saying, but short of using rcbos or having multiple boards and drastically increasing the cost then this is best solution.

 

[uksparks]

You can still heat the water by changing the changeover switch to the other board, plus there's a coal fire and two panel heaters in the house on the other board.

 

[davesparks]

Yes at the moment she will be waking up to a very cold house when the immersion does what immersions do best.

Is there only one immersion heater? An electrically heated cylinder should have two, one off peak element and one boost element.

 

[davesparks]

To be fair, it's quite acceptable work, you are giving valid points but just being ---- lol.
.

Clearly we work to different standards! To me that is not acceptable work and would be getting redone properly.

You think that's being ----? I haven't even started on painting the trunking in a colour match to the switchgear.

 

[uksparks]

There a single element in it, it's been gong fine for the last 20 years with no problems, it will only take one element too, not looking at spending out on a new tank as don't need it.

The cost soon creeps up when you think the smoke alarms cost £200 which was enough, I think the whole job came in at £1700 for the rewire parts only.

her nor I wanted to change the tank to a new one, ok when it breaks I'll change the way it works.

 

[uksparks]

Clearly we work to different standards! To me that is not acceptable work and would be getting redone properly.

You think that's being ----? I haven't even started on painting the trunking in a colour match to the switchgear.

If it was a paying customer then things would have been different and matching no doubt, but as I have done the rewire free of charge and single handedly, then it's good and done the job just fine.

 

[davesparks]

If anything I would apply higher standards to a job for close family than I would for a paying customer!
I take pride in my work and enjoy doing my job to the best standard possible.
Are you familiar with the phrase
"You are only as good as your last job"?

 

[davesparks]

And back on topic, are the two immersion supplies on the same phase?

And where is the coil fuse for the contactor?

 

[uksparks]

No, the two immersion supplies are on different phases, I hve a proper change over switch for this, properly labelled for400v and dual feeds and points of isolation...

The only fuse that I am aware of that would blow should it be overloaded is in the bck of the time clock across the outer pairs, so between L1 from top of Contactor and A1.

 

[davesparks]

Why not put them both on the same phase? I know what you have done is strictly right, but does not common sense dictate that you avoid having 415V in an enclosure if possible, especially in a domestic environment!

And why did you think the 400V labels were necessary?

I don't follow the bit about the fuse? What do you mean the only fuse you are aware of? Have you not designed the coil cct with appropriate fusing?

 

[uksparks]

I appreciate what you are saying about avoiding having 400v in an enclosure, but by having them on different phases you are less likely to be left without water should you lose a phase.

the 400v sticker, I was under the impression that you had to label anything above 230v...no?

the fusing, so what would you do then? Please explain, I have only replaced the contractor so not strictly speaking changed the bit before it, but should you be able to advise as to the best setup I'll happily incorporate it.

 

[davesparks]

Interesting point, but is be looking to consider the chances of a diyer working on that versus losing a phase of a three phase supply for a significant length of time.
Losing one phase of a small TP supply is pretty rare in my experience, especially for the length of time it takes a cylinder full of hot water to go cold.
Think about what the loss of a phase would entail, if it's a supply issue the DNO will be on it pretty quickly I'd have thought!

It could be the fuse in the head which goes I guess, but since it would be the fuse for your SP supply which goes then the whole house will be off so the hot water not heating will be secondary to the lack of lights and power.

Yes you have to label anything with a Uo above 230V where you would not normally expect it to be, but nothing in your install has a Uo above 230V
I agree that the changeover switch should be labelled regardless of that reg, due to fact anyone could open it up unwittingly.

You must have done more than change the contactor, the old one worked and this one didn't initially.
But regardless of that if the coil cct is unfused and just tapped off of the L1 terminal then you have the cables running to the timeswitch fused at 63A (in the exel) they don't look like 16mm to me
Obviously you don't always fuse down a coil cct, think about a basic DOL starter, but in this situation I would expect to see the coil cct fused down.
It's din mount contactor in a din rail enclosure so you could have easily popped a 1A MCB in there for the coil cct.

I'll see if I can post a pic of a recent lighting control I put together to illustrate this setup.

 

[uksparks]

I see what you mean about fusing it, I can probably stick a breaker in there, just fiddling the tails a bit, the excel is at 32A and the time switch claims it can take 78A according to the sheet in the back of it, I suppose its just the cable that can only take 26A being 2.5, hmm you have got me thinking.

I agree, there's nothing Uo @ 400v.