Help with 240v required.

[bertiebasset]

After a long thought I decided to position a power point outside for the MH. After getting all the cable, sockets etc. I then found out it needed a "qualified electrician" to either fit or sign off so I contacted said electrician who has just finished upgrading the old fuse box for a nice new consumer unit, checked if we needed a complete re-wire (fortunately not required as old (over 38 years old) wiring still has good insulation) and wired in the external socket. Today, plugged in the van to top up batteries and the whole lot has tripped in the house. Have been checking the van for faults and after consulting the handbook for my Autocruise Wentworth I find I have modified wiring. At some stage in its life it has had wiring for an inverter to be fitted and it seems somewhere between the mains input socket and the van consumer unit is a heavy duty relay (found behind the heater, accessed after removing 2 drawers.) I have had SWMBO indoors resetting the house trip (not circuit but main trip) every time I switch on the van circuit for heater, boiler, charger and fridge but the relay seems to be the culprit. I have an inverter which clips on the battery terminals and a fly lead plugs into the inverter giving power to lights, charger and sockets. I can only think this relay is there to avoid running the boiler and heater on inverted mains. Never had a problem with old fuse box at home nor when plugging in on site. Any ideas anyone please.

 

[Badknee]

Hmmmm, everything in van ok. Have new socket fitted not ok. I suspect new socket.
Can you plug the van into another socket say through a door/window to test?

 

[ceejayt]

If you normally plug your van in when out and about then it can't be anything to do with the van. It has to be either the new socket or possibly you have damaged your hook up cable?

 

[xsparks]

I would guess that the relay switches skts between mains input and inverter. I'm guessing that the new fuse board you had fitted now has an earth leakage trip and that is what's tripping. I would suspect a neutral earth fault which would not have been apparent beforehand.

 

[Lenny HB]

After a long thought I decided to position a power point outside for the MH. After getting all the cable, sockets etc. I then found out it needed a "qualified electrician"

They changed that a few years ago only applies to kitchens and bathrooms now. I still do everything myself gas & electric I don't want any of those bodging so called professions on my property.
I assume it is the RCD tripping in the house, unkely to be the relay, you need to disconnect everything in the van then with it connected to the mains reconnect one item at a time until you find what is tripping it. At a guess more likely to be a heating element Truma or fridge.

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[Badknee]

I assume it is the RCD tripping in the house, unkely to be the relay, you need to disconnect everything in the van then with it connected to the mains reconnect one item at a time until you find what is tripping it. At a guess more likely to be a heating element Truma or fridge.

But why now all of a sudden, all that's changed it seems is a new outdoor socket has been installed on the side of the house, why condemn the MoHo?

 

[DBK]

If you have had a new consumer unit fitted it will be much more sensitive than the old one. We had a hidden electrical problem in the house which only came to light when we had new circuit breakers installed in the house consumer unit. Although the old ones were only ten years old they were unable to detect a short between earth and neutral which tripped the new ones.

The fact that you have not had problems on sites doesn't mean anything as their circuit breakers are probably not as sensitiv as the ones now fitted in your house.

I suggest get your electrician back and ask him to do a megger test on the MH, I strongly suspect this will identify a wiring fault.

 

[Lenny HB]

But why now all of a sudden, all that's changed it seems is a new outdoor socket has been installed on the side of the house, why condemn the MoHo?

Just had a new consumer unit fitted probably connecting before without an RCD in the house, but you would expect the RCD in the van to have tripped. Problem with 2 RCD in series the one with the shortest trip time will trip first. Agree may not be the van, but if it only happens with the van plugged in it points to the van.
Worth checking the hook up lead to make sure there is no moisture inside the plug & socket. Only other way I can think is if the earth in the socket at one or other end has been crossed with live or neutral then it would trip when you plugged the van in.

 

[bertiebasset]

Thanks for the replies.

If you normally plug your van in when out and about then it can't be anything to do with the van. It has to be either the new socket or possibly you have damaged your hook up cable?

Thanks ceejayt, Hookup cable new and ok. Socket new as is fused spur. I have now connected van and switched off the 3 breakers in there, house system ok.

I would guess that the relay switches skts between mains input and inverter. I'm guessing that the new fuse board you had fitted now has an earth leakage trip and that is what's tripping. I would suspect a neutral earth fault which would not have been apparent beforehand.

Thanks xsparks, Have to agree with you.

I assume it is the RCD tripping in the house, unkely to be the relay, you need to disconnect everything in the van then with it connected to the mains reconnect one item at a time until you find what is tripping it. At a guess more likely to be a heating element Truma or fridge.

Thanks Lenny. I have the van in pieces now. The consumer unit in the van has 3 circuits. I am able to switch 2 on but on switching the 3rd it trips the mains in the house. All circuits are in the off position- Heater, Boiler, Fridge and charger, The first 3 have isolator sockets fitted and are in the off position. I have pulled the connector from the charger. 230v Lights (touch on/off) now removed. So all circuits off. If I try the test button it cuts off the power at the van board but when switching back on there is a click from behind heater (this relay) and the house RCD cuts out.

Hmmmm, everything in van ok. Have new socket fitted not ok. I suspect new socket.
Can you plug the van into another socket say through a door/window to test?

Thanks Paul, Will try with usual hookup lead tomorrow when I have rebuilt van.

van RCD with cover removed. LH input, Middle heater, fridge, boiler and 12v Charger, RH sockets

Relay behind drawers ??

 

[PeteH]

Can I clarify? 1) You had the house Consumer unit upgraded. 2) Did you connect the MoHo after the upgrade was done AND BEFORE the new Socket was fitted?. OR 3) only after the New Socket was put into service?. IF (2) and no trip, then the new socket is suspect. IF (3) then the new Consumer unit is Likely to be far more "Sensitive" and has detected a problem IN THE VAN.

EDIT:- Update;_ Which I note you have discovered since I posted!!!.

Pete

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[xsparks]

Now that you have located the circuit you will now need to gradually separate its components until you are able to reset the rcd .

 

[bertiebasset]

Thanks Pete. We have had a new consumer unit in to replace an old fuse box. I had run the cable from the new outside socket indoors (I actually connected the armoured cable to a 3pin plug and connected the van OK....to fuse box) When the electrical work was carried out the outside socket was connected via a fused spur and on its own RCD. That was last Thursday. The fun began today. Really think it is sensitively of new RCD unit. Only option is to remove relay and see.

 

[bertiebasset]

Now that you have located the circuit you will now need to gradually separate its components until you are able to reset the rcd .

Tks xsparks. On the van consumer unit pictured the right hand RCD is off but the cables it protects are the middle ones 4cables into the block. Even with these off, when testing the RCD when switching back on the house RCD trips. Once power to van is on, when switching the right hand RCD on it trips. I think this relay energises on plugging van in initially and something happens when switching on this other circuit. Have not yet worked out what the 3rd RCD protects.

 

[xsparks]

If you're rcd on your van is working correctly it should have tripped before .It either work's or it doesn't.Imagine the rcd as a seesaw with the neutral on one side and the live on the other all is ok if the load is equal but if some of the flow travels down the earth the load becomes unbalanced and that's when it trips. 30ma trip is 30ma new or old.

 

[bertiebasset]

If you're rcd on your van is working correctly it should have tripped before.

But the van is 10 years old so the RCD is at least 10 yrs old. The new house RCD may be very much more sensitive. will re-wire round this relay tomorrow and see it that cures it, if not will replace relay and keep looking, something is not right.

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[PeteH]

30ma trip is 30ma new or old.

Normally I would agree. But My Welder Works fine on one (Split) circuit. but if I swap it to the other side? "PloP!". and it does not matter how many times I try!! Weird? or what!. So I reckon there must be some "Manufacturing" (IN?) Tolerance at work?.

Pete

 

[peterc10]

They changed that a few years ago only applies to kitchens and bathrooms now.

also applies to any external work like this socket.

 

[xsparks]

If you can try the trip on the left hand side when you push the blue button it should trip if working correctly.The other three are double pole breakers protecting individual circuits. When you locate the faulty circuit gradually break it down. In respect to the relay try to remove the out going circuit so that you can prove whether or not if it's just the relay.

 

[Lenny HB]

I

also applies to any external work like this socket.

I brought a pre-wired one didn't I guv.

 

[bertiebasset]

In respect to the relay try to remove the out going circuit so that you can prove whether or not if it's just the relay.

Will do tomorrow, will photo the relay to show 8 pins, 3 wires, all earth connected together away from relay. Only out going line I think is the one to the inverter. other is 2 ends of power input cable as far as I can see. A few loops on relay. I think it is to isolate inverter when on mains but it shunts when mains plugged in so could be an imbalance on sides (left 4 pins brown, right 4 pins blue).... tomorrow in the light.

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[Treeeev]

Before you take your van to pieces, are you able to try it somewhere else (ie neighbour or friend) to see whether the same thing happens there? I suspect that your new consumer unit has been wired incorrectly. I had a similar instance after having a consumer unit fitted for the garage. My camper would be ok plugged into the house, but when it was plugged into the garage, the garage RCD would trip. Further investigation revealed that one of the neutrals was installed on the wrong side in the board. Once corrected, all ok.

For me, first steps would be try your van somewhere else, then if ok, call your electrician back

Cheers

Trevor

 

[xsparks]

This is a good point there are two neutrals in the fuse board and only one is covered by the rcd in a split load board. It's possible that the neutral is in the wrong bar causing an imbalance. It's not clear from the thread if the rcd is at the fuse board or separate.

 

[DBK]

If you have a 13A plug adaptor for your EHU lead try plugging the MH into a 13A socket in the house, ideally a socket which isn't on the same circuit breaker as the outside socket. If it still trips, and it isn't tripping when the MH is not connected then the problem is either the EHU lead or in the MH.

 

[TheBig1]

have you tried plugging in an alternate load in the outside socket, such as a kettle?

 

[bertiebasset]

Thanks for all the replies, It is now dark and cold outside so will be trying out all the suggestions in the morning before bypassing the relay. will let you know how I get on tomorrow.

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[Gorse Hill]

you would expect the RCD in the van to have tripped Problem with 2 RCD in series the one with the shortest trip time will trip first.

Unlikely there is discrimination between RCDs, both 30mA
Disconnection time for 30mA at 5 times current
RCD times are 300msec.@ x1. 40msec.@ x5. ( TT systems it's 200msec.@ x1. )
The trip time of 200ms at x1 is for the older RCD types BS4293, for BS EN 61008 trip times are 300ms max.
Depends how old the RCD is in the van, new in the house and there's no discrimination between the RCDs
When doing a ramp test on RCDs even from the same manufacture they all trip at slightly different times/mA (however within the required times to comply with the regs) so possibly why house tripping before van

 

[Wickolad]

Tks xsparks. On the van consumer unit pictured the right hand RCD is off but the cables it protects are the middle ones 4cables into the block. Even with these off, when testing the RCD when switching back on the house RCD trips. Once power to van is on, when switching the right hand RCD on it trips. I think this relay energises on plugging van in initially and something happens when switching on this other circuit. Have not yet worked out what the 3rd RCD protects.

I notice the 3rd RCD (right hand breaker) is 6 Amps, this should therefore be the 240V lighting circuit.

 

[Wickolad]

I've just had another look at your picture of the MH dist board and think it may be worth having a look what's under the black insulation tape that's around the left hand plug connector as it appears to have been off at some stage as not heat shrink like other two plugs. If work has been done on plug there could be a loose earth strand to neutral which could cause the problem as could lighting circuit, which trips house when turned on.

 

[bertiebasset]

Thanks Wickload. Will take a look later. I would expect it to trip all the time with that fault though. At the moment I can connect and have from L to R,,,,, main, 1st and 2nd on. It is when I switch the no. 3 on that the MAIN trip in the house lets go, also happens if I test the van RCD either on test "off" or switching on again. ??

 

[xsparks]

Although the first two breakers are on are they drawing current if not it will make no difference to the rcd. E.g. if one is supplying skts and nothing is switched on there will be no current flow.

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