Consumer unit advice

[MikeWillmott]

No it doesn’t & the advice is (imho) borderline dangerous. In this scenario you are relying on whatever MCB is in the EHU supply post to protect your internal wiring in the van. The “hoovering” analogy has a fundamental flaw, in an extension lead scenario, the fuse in the plug protects the extension lead. A standard 16A EHU plug doesn’t have a fuse & everything downstream relies on the supplying MCB for protection, this is an unknown quantity. It has been said many times, the protective device, be it an MCB/RCBO/fuse etc. is there to protect the cable attached to it & nothing else. Without an independent consumer unit in your van, all the mains wiring would have to be able to carry whatever current that the MCB (if any) is rated at in the EHU post, and on a campsite, this is an unknown quantity.

You’re right Salty!
I meant the RCD does the same job.
My thinking is that my socket is on 2.5mm2 cable and it’s impossible to overload it (unless I take my mig welder camping) so yes I am relying on the MCB in the supply post for an overload fault but I’m happy with that.
I guess I could take my MFU with me… Not going to!

 

[roadtripper]

I've had several failures (4 now to be precise) of exactly that unit in cabling I use for events - I wouldn't touch them with a barge pole. One of them failed jammed on as well, which is exciting.

Edited to add: no I didn't keep on buying them, I bought 4 to make my 13A-16A tails inherently protected and then all 4 failed at around 14-16 months of relatively light use.

I used to use the plug top RCDs for the same reason but everyone seems to be moving to the "weatherproof" sockets where they don't fit.

 

[MikeWillmott]

Gulp!
I may have change my thinking!!!

 

[Salty Spuds]

You’re right Salty!
I meant the RCD does the same job.
My thinking is that my socket is on 2.5mm2 cable and it’s impossible to overload it (unless I take my mig welder camping) so yes I am relying on the MCB in the supply post for an overload fault but I’m happy with that.
I guess I could take my MFU with me… Not going to!

Do you have a mains battery charger hardwired into the 240v side, e.g. a Sargeant/ Victron /Renogy etc?

 

[MikeWillmott]

Do you have a mains battery charger hardwired into the 240v side, e.g. a Sargeant/ Victron /Renogy etc?

Victron! Not hard wired just got a socket under the seat so I can use it elsewhere when required!

 

[EdH]

Hi all, reading this with interest and I noted that my campervan 2020 T6.1 conversion from Rolling Homes of Shrewsbury has a very strange electric set-up. Namely it hasn't got an standard consumer unit with trip fuses as I keep seeing with different conversions.

In our little utility cupboard in the rear there is a victron charger when on EHU with a Timeguard RCD10WPVN Conn Unit RCD, and a simple ENG Marine Systems 12v fuse box in the internal cupboard as per photos.

The campervan has only one 240v socket which we use to either plug a fan heater/cooler or a single ring induction hob when on EHU. We don't use anything over 2.5kw through the socket.




We have been using it like this since purchasing the campervan in 2020. Is this something that I should be concerned about?

 

[Salty Spuds]

Hi all, reading this with interest and I noted that my campervan 2020 T6.1 conversion from Rolling Homes of Shrewsbury has a very strange electric set-up. Namely it hasn't got an standard consumer unit with trip fuses as I keep seeing with different conversions.

In our little utility cupboard in the rear there is a victron charger when on EHU with a Timeguard RCD10WPVN Conn Unit RCD, and a simple ENG Marine Systems 12v fuse box in the internal cupboard as per photos.

The campervan has only one 240v socket which we use to either plug a fan heater/cooler or a single ring induction hob when on EHU. We don't use anything over 2.5kw through the socket.

View attachment 281015
View attachment 281011View attachment 281013View attachment 281014

We have been using it like this since purchasing the campervan in 2020. Is this something that I should be concerned about?

Nothing wrong with that setup. That's an RCD protected fused spur supplying one socket. Perfectly adequate.

 

[EdH]

Nothing wrong with that setup. That's an RCD protected fused spur supplying one socket. Perfectly adequate.

Aha, ok. Just got me thinking after seeing some fancy RCD boards on other campers.

What's the max wattage that I could draw before it trips or would it trip on a EHU post/outlet? Or is this solely to protect if there is a fault in the appliance/cable?

Thank you your response.

 

[Dellmassive]

The fuse in the holder will determine the max current.

The RCD trip is for any residdule current leaks,

I'd imagine that socket will be fused with a 13A fuse.?

 

[Salty Spuds]

Aha, ok. Just got me thinking after seeing some fancy RCD boards on other campers.

What's the max wattage that I could draw before it trips or would it trip on a EHU post/outlet? Or is this solely to protect if there is a fault in the appliance/cable?

Thank you your response.

Maximum current will be determined by the size of the fuse in the fused spur and/or the breaker in the EHU supply. The maximum size fuse the spur can take is 13A. Watts = Volts x Amps, so nominally around 3000W.
This is dependent on the EHU having a 16A breaker. The W=VxA calculation only applies to resistive loads like heating/grills/kettles etc. if you start using inductive loads like microwaves/induction hobs/motors etc. The situation gets murky. But we’ll not go there today.

 

[roadtripper]

Nothing wrong with that setup. That's an RCD protected fused spur supplying one socket. Perfectly adequate.

I'd add so long as the PE (earth) is bonded to the van chassis, which possibly may not have been done.

Otherwise any faults potentially put the van body live and the RCD will do nothing at that point.

Yes we can hope that the RCD trips in time when someone standing on the ground touches your van and completes the circuit, but it's much better practice to ensure the fault immediately trips the RCD.

 

[EdH]

I'd add so long as the PE (earth) is bonded to the van chassis, which possibly may not have been done.

Otherwise any faults potentially put the van body live and the RCD will do nothing at that point.

Yes we can hope that the RCD trips in time when someone standing on the ground touches your van and completes the circuit, but it's much better practice to ensure the fault immediately trips the RCD.

Hopefully, they are a reputable converters so surely they would think of that?

 

[Salty Spuds]

I'd add so long as the PE (earth) is bonded to the van chassis, which possibly may not have been done.

Otherwise any faults potentially put the van body live and the RCD will do nothing at that point.

Yes we can hope that the RCD trips in time when someone standing on the ground touches your van and completes the circuit, but it's much better practice to ensure the fault immediately trips the RCD.

Presumably if the test trip works on the RCD, then the earth is present.

 

[EAN]

Presumably if the test trip works on the RCD, then the earth is present.

That wouldn’t confirm whether the van’s chassis is PE bonded or not.

 

[roadtripper]

Hopefully, they are a reputable converters so surely they would think of that?

I'd hope so, but a number of threads on here also show up a level of confusion with gas and electric installs even amongst well known folks.

It's worth a double check either by checking the wiring (which might not be easy looking at your pictures) or a multimeter.

If you have a multimeter set it to the continuity test setting, plug the EHU lead into the van but not the mains and take the end of the EHU lead to somewhere you can easily reach a good ground in the van and then check continuity between the earth pin in the EHU lead and the van ground. Earth pin is always the longest in both 13A and 16A connectors.

 

[Badjamin]

I'd hope so, but a number of threads on here also show up a level of confusion with gas and electric installs even amongst well known folks.

It's worth a double check either by checking the wiring (which might not be easy looking at your pictures) or a multimeter.

If you have a multimeter set it to the continuity test setting, plug the EHU lead into the van but not the mains and take the end of the EHU lead to somewhere you can easily reach a good ground in the van and then check continuity between the earth pin in the EHU lead and the van ground. Earth pin is always the longest in both 13A and 16A connectors.

I love mulirimeter usage tips. I bought one and never used it and just assumed I'd know what to do with it. Continuity is a good one.

 

[roadtripper]

I love mulirimeter usage tips. I bought one and never used it and just assumed I'd know what to do with it. Continuity is a good one.

It's worth pointing out never do a continuity test between two things that might be at different voltages. In this case that's very unlikely but if you are tracing circuits best to start with voltage measurements - by its nature those are very high resistance so no current will flow through the multimeter.

 

[EAN]

It’s also worth pointing out that when checking earth connections, a continuity test, whilst it gives some indication, is not the same as an earth bonding test.

 

[roadtripper]

It’s also worth pointing out that when checking earth connections, a continuity test, whilst it gives some indication, is not the same as an earth bonding test.

Agreed - it's a test that can prove something isn't connected (if there is no connectivity) but if it shows a connection it's not sufficient to prove it's up to the task.

It's a good first test though with tools most folks working on a van should have to hand, I suggest it as a less disruptive first step compared to taking the panels off and tracing the wire (which also wouldn't necessarily prove a good earth bond)