Whats the cause?

[Amp David]

Had a customer mention to me the following issue he has.

They have no mains water, so have a pump that keeps 2 supply tanks filled. He tells me that every now and again the pump stops working and he has to reset it. According to him its caused by the power going of because the clock on the cooker always reverts back to 12 oclock as though its been powered off.

He tells me that nothing else is affected, even if they are watching TV, lights on etc, the problem can still occur but lights etc don't go out or flicker. So the only way he knows its happened is if the clock has reverted to 12 oclock or if he doesn't hear the pump kicking in to keep the tanks topped up.

The supply is a TT and although the house is aroung 1940, the bits of the electrical system i've seen so far are all in good condition with no DIY bodging done.

Just looking for some advice on what the problem could be.

 

[steamboatwilly]

Interesting. So, it's just on one circuit then? Everything else continues to work OK? Is there a rogue timer in circuit somewhere?

 

[oldtimer]

Let me get this right when he gets a power cut he has to reset the pump because he knows the clock on the cooker has reverted back to 12:00 ???

First things first here the more info you give the quicker we can diagnose the problem so
1. How is the house wired ie duel RCD or split board ?
2. If split is the cooker on the same side of the board the pump is on ? ie is the pump tripping that side of the board and taking the clock with it ?
3. If he has to "reset" the pump is this because it is supplied through a latched relay hence during a power dip it drops out?

I think the there will be some sort of float switch in the tanks energising the pump if and when required so it does not sound like the power cut is the problem because the pump would have to be running during all the power cuts when it actually runs if and when required. Also if the pump is wired via a contactor plus overload it could be telling you that it has problems ie has it been taken out and inspected to see if it is being fouled by a bit of rope or is there something stuck in the impeller causing it to trip if not and it is clear then check the actual pump/motor you could find that the bearings are gone or water has got in. If water then megger the motor cables to earth back in the house if you get 1-2meg then water is your problem

 

[Amp David]

Let me get this right when he gets a power cut he has to reset the pump because he knows the clock on the cooker has reverted back to 12:00 ???

I know sounds daft, but think he means that when the clock has gone back to its default time, he knows that the pump won't be working.

Still on 3036 rewireable fuses.

As of yet have not properly looked at the things you suggested as was there to price for underfloor heating and he mentioned it, so will hopefully be a little more work for me.

 

[oldtimer]

Forgot to add that 90% of the time it is water penitration into the motor ie unit runs for a couple of minutes then trips as I said make sure the mains are disconnected and megger L&N to earth also ask how old it is ie old metal job or brand new DI plastic body

 

[Amp David]

Cheers oldtimer. Can see what you are saying but still makes me wonder why his cooker is acting like its been powered off.

 

[oldtimer]

Dont take anything for granted it could be that there is a fuse descrimination problem or the pump has been spurred off the cooker remember some lazy spark may have wired it into the cooker supply because it was not being used at the time.

A couple called me out because their shower was not working I seen a cooker switch in the kitchen and a gas cooker and at the board a 30 amp fuse with one 6mm supply how can this be when there is a shower and a cooker ?? Then before i got the tools out I asked if the cooker switch was always off the reply was no I switched it off a couple of days ago and funny enough the shower stopped working.
Answers on a postcard please

 

[malcolmsanford]

I know sounds daft, but think he means that when the clock has gone back to its default time, he knows that the pump won't be working.

Still on 3036 rewireable fuses.

As of yet have not properly looked at the things you suggested as was there to price for underfloor heating and he mentioned it, so will hopefully be a little more work for me.

If he is losing power to the cooker circuit, assume he is having to rewre those 3036?? Way you put it Dave it seems he is not having to do that. .....................if not then why is the power going off? and how is it going off

 

[pushrod]

I would investigate the float switch (usually some sort of simple pressure switch i believe) first as these sort of pumps (if it is the sort i'm slightly familiar with) need resetting if they ever go dry. I would think that the clock is just sensitive to the voltage disturbance caused by the pump switching off. Might be worth checking how empty/full the respective tanks are when it trips.

 

[Amp David]

If he is losing power to the cooker circuit, assume he is having to rewre those 3036?? Way you put it Dave it seems he is not having to do that. .....................if not then why is the power going off? and how is it going off

Not having to rewire the fuse and why is the power going off, thats whats i'm after

 

[Crosswire]

Not having to rewire the fuse and why is the power going off, thats whats i'm after

So what is he resetting?

Sounds like the cooker is fed from the pump?! Sounds a bit stupid but can't thinkhow else could cause the symptoms...

 

[armbands0]

I have seen one of these installations, the water pump was controlled from a DOL, which would explain it not pumping after a loss of supply.

 

[pushrod]

I have seen one of these installations, the water pump was controlled from a DOL, which would explain it not pumping after a loss of supply.

My only experience of this sort of thing was when staying out in Cyprus - a well pump was feeding a big tank and there was a pump in that pumping up to a roof tank. There was a DOL starter with undervoltage protection that worked the well pump and a pressure sensor beside the 2nd pump that also needed resetting if the water ran out plus various submerged pressure pad switches.

I'll never take mains water for granted again