Help - EHU light is flashing and we're of for a few weeks tomorrow

[Hooflungdung]

We are planning to be on a ferry from Portsmouth tomorrow evening (Thurs) and just found an electrical fault on the van:

1. Orange EHU light on control panel was flashing - checked and breaker had tripped in workshop supply. Reset breaker and situation repeated with a breaker tripping further upstream. Stays on for up to a minute and then starts flashing.
2. I have plugged into an alternative circuit and get similar problem.
3. I have checked the EHU cable and seems fine – works OK on other equipment
4. Checked the dist board in the wardrobe in the camper and nothing had tripped but the test button on the RCCB doesn’t appear to be working – breaker does not trip when I press the test button.
5. Each time I plug the EHU cable into either the Workshop or House supply it seems to trip the circuit.
6. The breakers in the dist board inside the van don't appear to be tripping.

Van is a Adria Coral 2011 with a Shaudt LT 313A control panel.

The RCCB is a ABL Sursum RCCB RP2203. - Given that the test button on this unit doesn't seem to be working I wonder if it is possible/likely that this is the faulty item?

Needless to say we are sweating on this one a bit – why do things always fail just before you are going on a trip?



Any help/advice would be appreciated

 

[Landy Andy]

I assume you have 2 breakers and a main switch in the van.
Have you tried turning off the main switch and the two breakers, then see if supply trips. Then main switch on, then wait see if supply trips. Then one breaker on, and so on. It would be better to identify where/which circuit fault/issue is on. You should also try having all the 240v stuff off whist ping it, including the Shaudt unit.

 

[Hooflungdung]

Cheers Andy - Have tried some of that but will give it a wizz!

 

[Hooflungdung]

OK Looks like it may be the fridge. Tried with the main switch engaged and breakers off and the circuit didn't trip. The two circuit breakers on the van dist board are joined - when I switched these on the circuit tripped after less than 30 seconds. Fridge was switched on and set to AES so running on Gas till the breaker was engaged and then probably switched to 230v and tripped the circuit.

I then switched the Fridge off and repeated with the main switch and 2 breakers engaged and the ehu stays connected and doesn't trip the workshop breaker

We have had very heavy rain here today and I wonder if some water has got in through the vents and is upsetting the 240v. Fridge seems to operate OK on Gas - I will go and check the 12v now.

You can see on the attached image that the 2 circuit breakers are linked - i.e. one big switch.

 

[Hooflungdung]

Seems to be working OK on 12v - just waiting the obligatory 10 mins to see if the GAS kicks back in on AES (230v is disconnected).

Looks like I might need to get into the back of the fridge thru the vents with a hairdryer to see if it needs drying out,

^{_{Subscribers  do not see these advertisements}}

 

[TheBig1]

I will bet you that the fridge 240v element has failed short circuit. A relatively easy fix, even DiY

 

[JockandRita]

I will bet you that the fridge 240v element has failed short circuit. A relatively easy fix, even DiY

Agreed John, but maybe just not hours before leaving home for a ferry.

Jock.

 

[Hooflungdung]

I am travelling from Mid Wales to Portsmouth tomorrow - am I likely to be able to pick one up en-route and fix myself?

Fridge is a Dometic RMD 8 series

 

[TheBig1]

The heater elements on the fridge are a metal tube with a thin wire inside that heats up. When it fails, the thin wire snaps and can be short circuit if it touches the outer tube and open circuit if not. You describe classic symptoms of short circuit happens regularly.

Repair entails disconnecting the mains and accessing the back of the fridge. Unplug the wires and slide the element from the flue. Then slide new one in and plug new wires in

 

[jockaneezer]

Just disconnect the 240 volt element and enjoy your break on gas and 12 volts ?

^{_{Subscribers  do not see these advertisements}}

 

[TheBig1]

Prices vary, but I would ring a few caravan accessory shops on your route. Prices for the same part vary from £80 to £120. Buy on amazon or ebay to be delivered to a campsite you will be staying at. I presume campsite, as that is where you would get ehu. Otherwise unplug the wire and run on gas till you get home

 

[Landy Andy]

Seems to be working OK on 12v - just waiting the obligatory 10 mins to see if the GAS kicks back in on AES (230v is disconnected).

Looks like I might need to get into the back of the fridge thru the vents with a hairdryer to see if it needs drying out,

Good to have it isolated to a single item. Check the back of fridge for simple thing such as damp but if not I would plan to just use gas for the fridge when not travelling. On my Adria I have a uk socket and the fridge is just plugged into that, if yours is the same you can just turn socket off, or unplug the fridge.

 

[Hooflungdung]

Cheers guys - prompt and useful responses as usual. I will get back onto it first thing in the morning and take the panel off and resistance test the element to see if it is short or open circuit and maybe try hairdryer or blow heater in there if it looks wet. As suggested, the fridge works OK on gas & 12v so we should be able to manage without the 240v if need be.

Thanks again

 

[Hooflungdung]

Ok. I’ve had the covers off and checked the incoming socket and getting 240v. Taken the cover off the control box on back of fridge and getting 22 ohms across the 240v element. Just need to check whether that is correct. Fridge is a Dometic RMD 8505. No sign of any damp or wetness at top or bottom of fridge.

 

[StillGoing]

Ok. I’ve had the covers off and checked the incoming socket and getting 240v. Taken the cover off the control box on back of fridge and getting 22 ohms across the 240v element. Just need to check whether that is correct. Fridge is a Dometic RMD 8505. No sign of any damp or wetness at top or bottom of fridge.

The resistance on my 230V element was about 200 ohms.

^{_{Subscribers  do not see these advertisements}}

 

[autorouter]

You can see on the attached image that the 2 circuit breakers are linked - i.e. one big switch.

That trip switch marked C10 is a 10A double-pole Miniature Circuit Breaker (MCB). It is a single switch, but is double the width of a UK domestic (single pole) MCB. Another useful tip is that the test button on the RCCB doesn't activate the trip unless there is a mains supply to it. If there's no supply to the RCCB then the test button doesn't trip the switch.

 

[autorouter]

Ok. I’ve had the covers off and checked the incoming socket and getting 240v. Taken the cover off the control box on back of fridge and getting 22 ohms across the 240v element. Just need to check whether that is correct. Fridge is a Dometic RMD 8505. No sign of any damp or wetness at top or bottom of fridge.

The resistance should be about ten times that. Resistance = voltage squared over power. R = V x V / P. So a 200W element would have a resistance of 230 x 230 / 200 = 265 ohms.