MCB's should I carry spares?

[Odd-no-more]

On my last trip, after I got set up I noticed the leisure battery was not charging, I looked at the consumer unit and suspected the mcb had failed. I removed the cover and was about to check with a multi-meter when I noticed the plug to the onboard charger had come out, problem solved. However it occurred to me that if the mcb did fail when I was in a field miles from anywhere it would be a problem, especially as the mcb is double pole and possibly not easy to source. I only have 2 mcb's and they don't weigh much so is it worth it?

 

[Landy Andy]

You would end up carrying a lot of spare parts with that thinking.

They are fitted in houses and aren’t a regular fail, can’t see why can would be any different

 

[Sandancers]

Don't bother, they have such a low failure rate that the rest of your MH will give you loads more problems.

The show-stopper on our MH if it failed would be the electric table, but I don't carry a spare motor or electronics board for that. Sometimes you have just got to hope for the best. The next most vital bit, I'd suggest, would be the water pump. Don't carry a spare for that either.

 

[Al n Val]

TBH

in all my years of being an electrician (52) i’ve had to change very few MCB’s but I can see your point. For what they cost, and as you say weigh, you might as well carry spares
Belt n Braces

 

[Richard n Ann]

Just rewire into the other mcb that still works as a temporary fix

Cue regs argument

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

 

[RustyRuss]

I still work as a spark, in my experience (30+ years) you are more likely to fix or replace the items down stream from the MCB’s than the MCB’s themselves! More likely to fail, and that’s still VERY unlikely, is the RCD, I have replaced around 5 in 30 years and would take a guess at viewing 5-7000 consumer units in that time. Water pump or the solenoid pressure sensor valve/switch are much more likely candidates as spare parts!!

Cheers!

Russ

 

[Odd-no-more]

The next most vital bit, I'd suggest, would be the water pump. Don't carry a spare for that either.

I do have a "spare" water pump, it played up before a French trip so I replaced it, but got it working again so I keep it "just in case"

 

[Odd-no-more]

Just rewire into the other mcb that still works as a temporary fix

Cue regs argument

I have 2 one is 6 amp the other is 16 amp so I don't think I'd get away with that

 

[Odd-no-more]

I still work as a spark, in my experience (30+ years) you are more likely to fix or replace the items down stream from the MCB’s than the MCB’s themselves! More likely to fail, and that’s still VERY unlikely, is the RCD, I have replaced around 5 in 30 years and would take a guess at viewing 5-7000 consumer units in that time. Water pump or the solenoid pressure sensor valve/switch are much more likely candidates as spare parts!!

Cheers!

Russ

I had an RCD fail, it was on my drive, I was testing the van's electrics and did an earth loop test and the RCD wouldn't reset, that was off the shelf from B&Q but double pole mcb's are not so easy to find, also I would run without the RCD as the post should have one I wouldn't be happy without the 6 amp mcb though, the 16 amp maybe, as again the post should have protection for that

 

[Grummyb]

I still work as a spark, in my experience (30+ years) you are more likely to fix or replace the items down stream from the MCB’s than the MCB’s themselves! More likely to fail, and that’s still VERY unlikely, is the RCD, I have replaced around 5 in 30 years and would take a guess at viewing 5-7000 consumer units in that time. Water pump or the solenoid pressure sensor valve/switch are much more likely candidates as spare parts!!

Cheers!

Russ

I'm not an electrician but id say if you've got a stream running down your wires your in a lot if trouble

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

 

[peterc10]

It depends upon how you use your motorhome.

The only important thing that relies upon mains electrics on our motorhome is the wife's hairdryer, and we have an inverter that can power that. Everything else, including lighting, TV, shaver, phones, ipad, laptop, vacuum cleaner, radio, lights, water pump, refrigeration, heating and cooking relies upon 12v or gas for power. We have solar which is capable of keeping the batteries topped up for most of the year and refillable bottles for the gas. That is why we usually spend most of our time not plugged into an EHU.

So for us an MCB or RCD failing would be a very minor inconvenience. The only spares we always carry are 12v fuses, a water pump and vehicle light bulbs.

 

[Odd-no-more]

I have had a search and finding double pole mcb's with c curve is not easy, so I've decided for the little extra weight I will get some for spare, when I was working I did have a couple of mbc's that would not reset after going off, they were the more standard single pole ones that can be bought anywhere, so as I'm cautious about spares I will feel happier with them on board. we're off on a 3 day trip this Monday, that is off grid so not needed but I will order a couple when we get back.

Thank everyone for the input

 

[two]

If you were "in a field miles from anywhere" you probably wouldn't have EHU!
Try not to over-think possibilities or you'll end up taking two motorhomes "just in case".

 

[Landy Andy]

Do you have a space in the consumer unit? You could store it fitted, if you do choose to carry a spare.

 

[Trevor Wbm]

Except maybe in the Highlands or deepest Wales, you're never that far from a Screwstation or Toolfix.

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

 

[Brains]

I carry a spare pump and a spare tyre
Thats it

 

[pagey]

i had one fail some years ago but i was in a cl in a boat yard so i was able to get one from them

 

[Odd-no-more]

you'll end up taking two motorhomes "just in case".

Good idea, would one go on an A frame

Except maybe in the Highlands or deepest Wales, you're never that far from a Screwstation or Toolfix.

They don't stock them, that's why I'm concerned

 

[cmcardle75]

I have had a search and finding double pole mcb's with c curve is not easy, so I've decided for the little extra weight I will get some for spare, when I was working I did have a couple of mbc's that would not reset after going off, they were the more standard single pole ones that can be bought anywhere, so as I'm cautious about spares I will feel happier with them on board. we're off on a 3 day trip this Monday, that is off grid so not needed but I will order a couple when we get back.

Thank everyone for the input

Why would you want C curve? Are you powering some industrial machinery? It won't help even if you did. There's a good chance the campsite has a B curve upstream of you which is now more likely to trip and not be resetable.

 

[Odd-no-more]

Why would you want C curve? Are you powering some industrial machinery? It won't help even if you did. There's a good chance the campsite has a B curve upstream of you which is now more likely to trip and not be resetable.

I'm looking at like for like, also I have an inverter which may well have a high startup draw

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

 

[cmcardle75]

I'm looking at like for like, also I have an inverter which may well have a high startup draw

The inverter will be supplying AC current, not drawing it?

'C' curves are rarely used outside industrial applications. For domestic I'd use 'B' curves except for some very rare scenarios, basically hobbyists doing basically industrial things with high inrush currents and poor power factors (which should be corrected these days).

It's not like a 'B' instantly trips. It allows at least 3 times nominal current for startup loads.

 

[Bewildered]

No

 

[St3v3]

They don't stock them, that's why I'm concerned

It could be replaced with a single pole MCB and a connector for the neutral or connect to the neutral bar, depending on the unit. Check the hookup polarity to be sure.

 

[Trackman]

A spare water pump is a good idea imho. I always carry one on my boat having had 3 or 4 fail in 15 years on this boat, usually at an inconvenient moment.
Current spare is the last failure, repaired. I figure it will possibly fail again, but hope that's not before I get a new replacement!

 

[Odd-no-more]

The inverter will be supplying AC current, not drawing it?

'C' curves are rarely used outside industrial applications. For domestic I'd use 'B' curves except for some very rare scenarios, basically hobbyists doing basically industrial things with high inrush currents and poor power factors (which should be corrected these days).

It's not like a 'B' instantly trips. It allows at least 3 times nominal current for startup loads.

I am looking to replace with with what is already there, possibly because the battery charger is on the 6 amp and due to capacitance may have a surege draw above 6 amp a on startup

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

 

[cmcardle75]

I am looking to replace with with what is already there, possibly because the battery charger is on the 6 amp and due to capacitance may have a surege draw above 6 amp a on startup

There is no way a battery charger would benefit from a 'C' curve. A 'C' curve sounds inappropriate for the application and a 'B' curve would be safer. A 'B' already allows for any in-rush currents that you'd find in a domestic situation. I'd hardly expect any at all from modern solid state equipment such as a battery charger.

A 'C' curve is for inrush currents that exceed norms, such as for large industrial machinery, commercial lifts or large arrays of fluorescent lighting.

 

[Richard n Ann]

The coldstores I used to commission always had C or D rated breakers.. And they were BIG enough to park a motorhome in

 

[Odd-no-more]

There is no way a battery charger would benefit from a 'C' curve. A 'C' curve sounds inappropriate for the application and a 'B' curve would be safer. A 'B' already allows for any in-rush currents that you'd find in a domestic situation. I'd hardly expect any at all from modern solid state equipment such as a battery charger.

A 'C' curve is for inrush currents that exceed norms, such as for large industrial machinery, commercial lifts or large arrays of fluorescent lighting.

The original fitting is C it's what is there now, shouldd I replace them with B's

 

[cmcardle75]

The original fitting is C it's what is there now, shouldd I replace them with B's

Basically yes, replace with 'B' unless you have a qualified person saying that 'C' really was appropriate.

 

[Odd-no-more]

Basically yes, replace with 'B' unless you have a qualified person saying that 'C' really was appropriate.

I will get 2 b's and fit them, I'll keep the original C's as spare.
If they don't work I'll blame you

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