Mains Electricity advice please

Revolvor

Revolvor

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I've just purchased a small consumer unit to wire up my new Victron Inverter in my van.

Looking at the details on the RCD, I'm worried about the specifications:

It states 30mA and <0.1s

Should it not be < 40ms to be safe?

IMG_20231227_104601014.jpg
 
portable electrical equipment and temporary line, should be installed in the operating current of 30ma circuit, operation time leakage circuit breakers within 0.1s...

however

The IEE Regs for Caravan / Motorhome regs say

The RCD must comply with BS EN 61008-1 or BS EN 61009-1, interrupt all live (line and neutral) conductors and have the characteristics specified in Regulation 415.1.1 (I!n ≤ 30 mA and operating time ≤ 40 ms at a residual current of 5I!n).

personally I would be happy with 0.1s .... a faster trip time is safer . but you may get nuisance trips.
 
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The trip time & current is correct but Type B RCD & MCB's would be better as Type C trip on much higher overload. Type C is more suitable for industrial applications where as type B is better for domestic applications.

EDIT:
40ma would be less safe as if you were to touch a live wire it would allow more current to flow through your body before tripping.
 
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Lenny HB said:
Type C is more suitable for industrial applications where as type B is better for domestic applications.
Click to expand...
well spotted.. didn't look at the MCB type
 
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Lenny HB and scotjimland

Thank you both for your replies and advice.

Would you recommend that I return the consumer unit and purchase something more suitable?

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If it's easy to return then yes. MCB's are not essential on an inverter as the electronics in the inverter will shut it down probably before the MCB trips but an RCD is good idea providing one side of the inverter output is grounded, Victron's are as standard.
 
Lenny HB and scotjimland

Again, thanks. My daughter bought it for me from Amazon. She's seeing if she can return it.

I'm only adding 2x sockets for my 500W. Inverter. Can I just have one Type B MCB feeding both sockets radially, and get a Type B 40ms 30mA RCD?
 
Revolvor said:
. My daughter bought it for me from Amazon. She's seeing if she can return it.
Click to expand...

If they are difficult about a return, how is it described? If it's anything domestic it doesn't really meet that description.
 
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Revolvor said:
Lenny HB and scotjimland

Again, thanks. My daughter bought it for me from Amazon. She's seeing if she can return it.

I'm only adding 2x sockets for my 500W. Inverter. Can I just have one Type B MCB feeding both sockets radially, and get a Type B 40ms 30mA RCD?
Click to expand...
Yes that will be fine
Revolvor said:
VACANON Garage Consumer Unit 2 Way RCD Circuit Breaker Panel Garage Caravan Consumer Unit Anti-leakage Fuse Box 40A 30mA RCD 2MCB 6A+ 16A Amazon product ASIN B0BWN92VJN
Click to expand...
Those are type C.
 
Sorry to bear bad news, but you need to know that a standard UK garage consumer unit is totally unsuitable for a motorhome/campervan electrics consumer unit. For a start, the MCBs are both single pole, and they need to be double-pole, or at least 1P+N.

Not only that, but the RCD looks like it's single pole switching, not double pole, and that is definitely more serious.

You will struggle to find double-pole MCBs and RCDs in the UK in DIY stores, you need to go to specialist stores like CEF. Hookup Connection units for connecting caravans are usually OK though.
 
And I may add, the often confusion mix up: type / curve.
RCD has a type rating, mcb a curve rating or, rcbo has both. Don’t mix the mcb breaking curve with the rcd type disconnect. Both mean different things.
Type B rcd detects ac and dc current leakage, so it’s used where AC and DC exists in a system, ie. inverters. Type C rcd does detect AC but only pulsing DC, so less DC detection.
On mcb’s or breakers, the B has less delay time for tripping on the rated current, where a C curve will allow for some sustained surge above the rated current before breaking. Both will protect the conductor if sized aproprietly.

Now, on a 500w inverter, I would personally have a C3 or B3 mcb for over current protection. The 500w Victron is double insulated, no neutral, and no rcd functionality.
 
autorouter said:
Sorry to bear bad news, but you need to know that a standard UK garage consumer unit is totally unsuitable for a motorhome/campervan electrics consumer unit. For a start, the MCBs are both single pole, and they need to be double-pole, or at least 1P+N.

Not only that, but the RCD looks like it's single pole switching, not double pole, and that is definitely more serious.

You will struggle to find double-pole MCBs and RCDs in the UK in DIY stores, you need to go to specialist stores like CEF. Hookup Connection units for connecting caravans are usually OK though.
Click to expand...
sorry for the late reply - I've been busy today.

Thanks for the comments about the need to have double pole RCDs and MCBs.

The consumer unit I purchased is being returned, so I am starting from scratch.

In my research last night, I was reading about RCBOs. As I will only have 1x radial circuit, could I just use a 2-Pole Isolation switch together with a 2-Pole RCBO, such as this?

DP RCBO

I have been increasingly puzzed that with the large numbers of people fitting inverters in their MHs, why the subject of RCD and MCB specifications have not been discussed more on the MH Forum. Do people just plug into the 13A Socket(s) on their Inverter, with no additional protection?
 
Raul said:
And I may add, the often confusion mix up: type / curve.
RCD has a type rating, mcb a curve rating or, rcbo has both. Don’t mix the mcb breaking curve with the rcd type disconnect. Both mean different things.
Type B rcd detects ac and dc current leakage, so it’s used where AC and DC exists in a system, ie. inverters. Type C rcd does detect AC but only pulsing DC, so less DC detection.
On mcb’s or breakers, the B has less delay time for tripping on the rated current, where a C curve will allow for some sustained surge above the rated current before breaking. Both will protect the conductor if sized aproprietly.

Now, on a 500w inverter, I would personally have a C3 or B3 mcb for over current protection. The 500w Victron is double insulated, no neutral, and no rcd functionality.
Click to expand...
Again, sorry for the late reply.

It really is quite complicated for someone without specialised knowledge, which is why I am asking, as I want to get it right. There has been conflicting advice in this thread, so I am still confused. :giggle:

You mention no RCD functionality in a Victron Inverter, but in a previous thread I started, asking about earthing for inverters, you posted this: Is it not applicable anymore?

"Ok, for ve direct models is easy. Take cover of and move yellow wire( PE) from right to the spade connector near the yellow component, over the transformer See apendix A page 12 in the manual for the pictures and detailed explanation. Once you do that, you have neutral bonded to chassis/earth PE, and RCD will operate as intended."

https://www.victronenergy.com/uploa...-VE.Direct-250VA-1200VA-EN-NL-FR-DE-ES-IT.pdf

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Revolvor said:
Do people just plug into the 13A Socket(s) on their Inverter, with no additional protection?
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Inverters are an isolated output so an RCD is not really necessary. To use an RCD with an inverter one side of the output has to be grounded.
Raul pointed out in an eairler post your inverter does not have a grounded output so you need to check the manual to see if it is OK to ground one side.
 
Lenny HB said:
Inverters are an isolated output so an RCD is not really necessary. To use an RCD with an inverter one side of the output has to be grounded.
Raul pointed out in an eairler post your inverter does not have a grounded output so you need to check the manual to see if it is OK to ground one side.
Click to expand...
The link that Raul posted earlier in the year includes this modification to link the Earth and Neutral, which is what I had intended to do

1703797167834.png
 
Lenny HB said:
..........MCB's are not essential on an inverter as the electronics in the inverter will shut it down probably before the MCB trips but an RCD is good idea providing one side of the inverter output is grounded, Victron's are as standard
Click to expand...
Lenny HB said:
Inverters are an isolated output so an RCD is not really necessary. To use an RCD with an inverter one side of the output has to be grounded.
Raul pointed out in an earlier post your inverter does not have a grounded output so you need to check the manual to see if it is OK to ground one side.
Click to expand...
Revolvor said:
The link that Raul posted earlier in the year includes this modification to link the Earth and Neutral, which is what I had intended to do
Click to expand...
In view of these and other comments, is it sufficient for me to install a double pole isolator, and double pole RCD, and rely on the inverter to shut down any overload?
 
Revolvor said:
In view of these and other comments, is it sufficient for me to install a double pole isolator, and double pole RCD, and rely on the inverter to shut down any overload?
Click to expand...
You can do the PE bond for sure, and will enable the rcd to work properly. But you have to be mindful this will render the double insulation properties of the inverter. The more important protection you need to concentrate at, is over current protection. If it was a larger inverter with possibility to run various bigger things I would bond the neutral. But for a small 500va double insulated the over current protection will be enough. And no more than a 3A mcb, otherwise will never trip.
What are you using this inverter for?
 
Raul said:
..... What are you using this inverter for?
Click to expand...
It will only be for occasional use. Charging my e-bike battery and powering my Starlink dish when off-grid. Most things work/charge from 12v or USB.

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Raul said:
Wire a 3 pin plug to a socket, put a 3A fuse in the plug, plug it in the inverter, and use that socket. Job done.
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Thank you!! ( ..... and to all the others who contributed to this thread)

It took a while to get there, but that was also the conclusion I was coming to. However, it is good to have a "sanity check" from people that know more about it than me.

Happy New Year to all!
 
Revolvor said:
In my research last night, I was reading about RCBOs. As I will only have 1x radial circuit, could I just use a 2-Pole Isolation switch together with a 2-Pole RCBO, such as this?

DP RCBO
Click to expand...
I like the socket with 3A fused plug solution. I know you aren't going to use an RCBO, but thought I'd point out that the 'DP RCBO' in your link is not in fact a double pole RCBO. There is a neutral wire connected to it, but that is simply for ensuring the RCD functionality works. When it trips, it only switches off the live wire, not the neutral wire.

This is acceptable in UK domestic fixed wiring, where everything is tested for polarity before certification. However such single-pole circuits are not acceptable on mobile installations such as motorhomes and campervans, where proper double pole RCBOs, RCDs and MCBs are required.

I don't know why they are described as 'DP' in the advertising information. I suspect it's either a typo, or even a genuine mistake by whoever was writing the advertising website. Very misleading, but unfortunately quite common in website ads.
 

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