External socket?

[Parody]

Good evening

Before I ask, if I need an Electrician then so it be it I’d rather do it via the book than not be safe. Anyhow I’m wanting to install an external socket down the side of our house, the most direct way to connect it up would to use the washing machine redial direct what goes from the consumer unit to a 1gang socket via 2.5mm t&e cable , what Wanting todo is to put FCU in-line so I could spur off to the external socket. Am I allowed todo this myself without having a Electrician involved.

many thanks

 

[plugwash]

Assuming the work doesn't involve a new circuit and doesn't involve work within the zones of a bathroom or in a room containing a swimming pool or sauna heater, then it's not notifiable.

There is no electrical need for a FCU, you can use one if you want but a plain junction box or a 20A switch would be fine too.

However before spurring a new socket off a 16A circuit that already supplies a washing machine, I would ask yourself what you plan to use the socket for. If it's for occasional garden tools then it's probablly fine. If it's for charging an EV then I would be more skeptical of the idea.

 

[AndyPRK]

You should get a BG rcbo really. B20

 

[Parody]

Assuming the work doesn't involve a new circuit and doesn't involve work within the zones of a bathroom or in a room containing a swimming pool or sauna heater, then it's not notifiable.

There is no electrical need for a FCU, you can use one if you want but a plain junction box or a 20A switch would be fine too.

However before spurring a new socket off a 16A circuit that already supplies a washing machine, I would ask yourself what you plan to use the socket for. If it's for occasional garden tools then it's probablly fine. If it's for charging an EV then I would be more skeptical of the idea.

thanks for your reply, the socket will used to connect our micro caravan up when it at home, mainly just to charge the 12v leisure battery up and to use the odd 700w heater.

 

[winston1]

Why not run it from one of the two spare 16 A MCBs in your CU?

 

[ericmark]

the socket will used to connect our micro caravan up when it at home

Then I would leave the 16A RCBO as it is and simply fit a 16 amp socket.

 

[Harry Bloomfield]

Then I would leave the 16A RCBO as it is and simply fit a 16 amp socket.

Why 16amp, a 13amp outdoor socket is much more generally useful. The caravan can then be powered via a 13amp to 16amp adaptor, which is exactly what I have here. The adaptors are generally available.

 

[ericmark]

Personally I used a smart charger class II direct onto the caravan battery, so yes 13 amp socket, the reason was.
1) If a cell goes short circuit maximum charge 0.8 amp.
2) House supply TN-C-S and not permitted to use that for a caravan.
3) Smart charger auto turns off and on as required and less likely to over charge battery.
I have talked about the TN-C-S supply a lot, as father-in-law also charged his motor caravan. And he pointed out the gas and electric meter cupboards were so close to caravan to have a different earth is dangerous, and since parked on concrete slabs unlikely to cause a problem even if PEN lost.

Although covered in section 708 in a caravan park the fire regulations mean the caravan must be from memory 2.7 meters from any building, but when parked at home that was not the case.

So technically I was not supplying a caravan I was supplying a class II smart charger with no earth connection so safe even with loss of PEN.

I use a converter other way around, 16 to 13 amp for lawn mower etc, as they are only used in the dry, where the motor caravan will have a supply in all weathers.

Maybe I was wrong not to warn about supply with-out PEN protection and DC monitoring, etc. This can be debated.

 

[Harry Bloomfield]

Personally I used a smart charger class II direct onto the caravan battery, so yes 13 amp socket, the reason was.
1) If a cell goes short circuit maximum charge 0.8 amp.
2) House supply TN-C-S and not permitted to use that for a caravan.
3) Smart charger auto turns off and on as required and less likely to over charge battery.
I have talked about the TN-C-S supply a lot, as father-in-law also charged his motor caravan. And he pointed out the gas and electric meter cupboards were so close to caravan to have a different earth is dangerous, and since parked on concrete slabs unlikely to cause a problem even if PEN lost.

Although covered in section 708 in a caravan park the fire regulations mean the caravan must be from memory 2.7 meters from any building, but when parked at home that was not the case.

So technically I was not supplying a caravan I was supplying a class II smart charger with no earth connection so safe even with loss of PEN.

I use a converter other way around, 16 to 13 amp for lawn mower etc, as they are only used in the dry, where the motor caravan will have a supply in all weathers.

Maybe I was wrong not to warn about supply with-out PEN protection and DC monitoring, etc. This can be debated.

I have - 13amp socket, 13amp to 16amp adaptor, Orange EHU, plugged in to caravan permanently and so PSU powered, but with battery disconnected. Once per month, I reconnect battery for a day or two, to top it up. I plug smart charger in, in caravan to give the battery a final boost, when I turn fridge/freezer on a day prior to hooking up and driving off.

 

[ericmark]

I think we have all considered how to maintain the caravan battery, I was considering what to do as have a 95 Ah AGM and had a 75 Ah flooded with the flooded easy enough to top up if over charged, but not so easy with AGM, it came out of JAG as faulty, but then found fault was wife's light right foot not pressing brake hard enough for car to start, so old battery was to be used in caravan. However then found whole caravan beyond economic repair so scraped, so problem for me went.

But it does seem caravan built in chargers do run at a high voltage, BS 7671 says

the output terminals of the supply unit should be maintained between 11 V minimum and 14 V maximum with applied loads varying from 0.5 A minimum up to the maximum rated load of the supply unit.

but it seems manufacturers don't take any notice of that, and really even 14 volt too high, to maintain the battery I would look at between 13.2 and 13.4 volt.

The smart charger has a lower limit of 12.8 and upper limit of 14.4 volt, each time it reaches 14.4 volt it switches off, until the battery drops to 12.8 volt, so it is doing what you are manually doing when you put it on charge once a month, most of the time it seems to sit at 12.9 and then a spike as it switches on then off again and quickly drops to 12.9 again, only thing is I connect and forget.

Two caravans ago I walked past it parked on father-in-laws drive, and thought some thing wrong with drains, smell of hydrogen sulphide, then it twigged, and yes cell gone short circuit, had I not realised it could have taken out the built in charger, and clearly an explosion risk if any smokers walked past, 18 amp of built in charger is great in use, but in storage can cause a problem. So the Lidi smart charger once it drops charge rate from 3.8 then 3 to 0.8 amp will not return to higher output it will go between zero, 0.1 and 0.8 amp so no real risk of explosion if the battery fails.

This was the result with a mobility scooter battery 35 Ah with just a 4 amp charger when a cell went short circuit, bad bit was it also took out the other battery of the pair, as 24 volt.

 

[Harry Bloomfield]

But it does seem caravan built in chargers do run at a high voltage, BS 7671 says but it seems manufacturers don't take any notice of that, and really even 14 volt too high, to maintain the battery I would look at between 13.2 and 13.4 volt.

I compromised with my own voltage calibration, by setting it at 13.8v as a good compromise between putting charge back in it once on EHU and overcharging it, combined with regime whilst at home of disconnecting the battery except for two days per month or two.

 

[AndyPRK]

Why not run it from one of the two spare 16 A MCBs in your CU?

As outdoor sockets should be RCD protected.
Well, all sockets actually