Granny charger / multiplug

kevincork · 06-12-2020 12:54pm #1

I know this is not advised, but I'm running out of outdoor plugs and I have a Nissan Leaf and a Volvo XC90 T8.

I have one outdoor plug for the Nissan Leaf with is fine but the another side of the door the second plug is also used for the CCTV (I know it's a bit weird but I'm only renting I couldn't make some messy wiring)

My idea was to plug both the CCTV (which have a 12W led light integrated) and the Volvo XC90 T8 using this plug

When plug on it own, I usually charge the Volvo at 10Amp but because I'm sharing the main plug I decided to try at 8Amp unfortunately that blowed the fuse.

I could try to charge at 6 Amp perhaps ?
Otherwise I could use a another plug from the back garden and a Type 2 extension lead (which by the way I'm not sure, is it a single phase or 3 phase?)

I found this cable here I guess this would work (although super pricy) or this

or perhaps I can use a adaptor for the Nissan Leaf charger to transform to a type 2 but that would mean that I can't charge both together every night.

Black_Knight · 06-12-2020 1:50pm

I'm confused. I get the impression you don't have a car charger on your residence, but then you talk about buying a 20 meter Type 2 cable from the rear of the house, suggesting there's a charge point installed at the rear. You have a leaf, so I'm assuming you now something about the different cable types (type2 to type2, 3pin/granny cable etc). If its domestic, a single phase cable is all you'd want.

Anyways, that meross splitter is rated for 10Amp, but says to not use it on high power units. Charging a car would fall under this bracket. I guarantee it will fail on you if you use it. An extension lead (13amp rated one from your local hardware shop will do you fine if you want to run power from the rear of the house. Unravel it entirely though, as the many hours of high current drawn through it will heat the cable up, and it can melt as a result if not unwound (when wound up, the heat cannot escape).

As for the Volvo blowing the fuse at 8Amp, that's worrying in general:eek:. A kettle, dishwasher or washing machine would pull that current. What fuse is it blowing? The one on the fuse box? :eek:

FYI, the CCTV is negligible in terms of power draw. 12W is nothing.

kevincork · 06-12-2020 2:31pm

Black_Knight wrote: »

I'm confused. I get the impression you don't have a car charger on your residence, but then you talk about buying a 20 meter Type 2 cable from the rear of the house, suggesting there's a charge point installed at the rear. You have a leaf, so I'm assuming you now something about the different cable types (type2 to type2, 3pin/granny cable etc). If its domestic, a single phase cable is all you'd want.

Anyways, that meross splitter is rated for 10Amp, but says to not use it on high power units. Charging a car would fall under this bracket. I guarantee it will fail on you if you use it. An extension lead (13amp rated one from your local hardware shop will do you fine if you want to run power from the rear of the house. Unravel it entirely though, as the many hours of high current drawn through it will heat the cable up, and it can melt as a result if not unwound (when wound up, the heat cannot escape).

As for the Volvo blowing the fuse at 8Amp, that's worrying in general:eek:. A kettle, dishwasher or washing machine would pull that current. What fuse is it blowing? The one on the fuse box? :eek:

FYI, the CCTV is negligible in terms of power draw. 12W is nothing.

Thank for your reply,
Sorry my primary post was very confusing.

I have two granny chargers, one for the volvo one for the nissan.
I was actually just looking for an outdoor 13amp extension lead as I though it could be a good alternatif > I would leave it unravel alright.

the issue with the fuse is when I connected both the CCTV camera and the Volvo with the meross splitter, which thinking about it, I think it's from the camera lead, I had a few issue in the past (while only the camera was connected, I will add some silicon around the socket).

Coming back from the extention lead I found a few one online (This and this

I wonder how many watts would the granny charger use, probably something near 2.4Kw right?
Thanks again.

PS : the type 2 extension lead was to connect from what side of the Volvo granny charger and the another to the car, but it's over 450€ so I think the 13amp 3pin extension lead will do just fine

AutoTuning · 06-12-2020 2:39pm

An Irish domestic socket is rated at 13 amps (continental ones are usually 16 amps).

If you’re using an extension reel, the cable may be thinner than is safe to use for an extended period at high load. That’s why they are sometimes fused at 10 amps. The plug fuse is there to protect the cable, and can be picked to protect something by limiting the load to less than the maximum a socket can supply.

If you’re using something that draws a sustained load at high amperage, 10 amps+ you really need proper fixed wiring to a socket, or at the very least a heavy duty reel, similar to what might be used on a building site and that should be unwound fully to prevent heat build up.

Normal extension leads are designed for light loads like gardening equipment, which are usually not drawing continuous loads and are often <5 amps.

The diameter of the metal conductors in the cable and the length of the reel dictate the safe load limit, not the plug or socket type.

Plug in something like a car charger or a heater and there’s a fairly significant possibility of melting the reel and even causing a fire.

stimpson · 06-12-2020 2:43pm

Using a heavy duty extension lead with a granny cable is not recommended. Using a splitter is a bad idea. If you were plugging in both cars on the same double socket then I think you are looking for trouble.

Either car will pull a heavy load for a long period of time so any issues with the wiring at all could cause problems (and by problems I mean your house could burn down)

I have a heavy duty (ie. rated for 13 amps and brand name) extension lead that I use very occasionally with my granny plug. I’m not giving advice here, but if I had 2 EVs and had to use extension leads then I would ensure they are both on different circuits (IE go back to different beakers on the fuse board).

Having said that, if I had 2 EVs I would install a proper charger and alternate them every night with a granny cable for emergencies.

And +1 on unrolling the cable every time. It will melt if you don’t.

AutoTuning · 06-12-2020 2:53pm

It’s very important to remember a double socket is absolutely not rated to carry 26 amps (2 x 13 amps). Typically they’re rated at 13 or 20 amps (good brands like MK) absolute max.

If they’re on a 16 or 20 amp radial circuit, fairly typical in Ireland, a the circuit breaker will trip if you exceed the rating.

If they’re on a ring circuit (often rated 32 amps) they won’t trip until the MCB limit is reached and that can be enough to melt the socket. This type of circuit is the most common type used in the U.K. and it is permitted and common here too, just a bit less so as we historically used a more continental approach to wiring.

So assume your safe limit for a double plate is still 13Amps in total for both sockets added together.

Bursty loads running for short times - most domestic appliances / kitchen appliances etc only draw their full load for a short time, eg your kettle boiling, your dishwasher or washing machine heating water etc but something like a car charger or a plug in heater draws high load continuously and that’s where you’ll get heat building up and melting fittings and wiring.

Relatively few appliances, other than heaters and perhaps old vented through the wall tumble dryers and a few things like small plug in ovens could really max out a socket.

Car chargers absolutely can!

kevincork · 06-12-2020 3:16pm

AutoTuning wrote: »

An Irish domestic socket is rated at 13 amps (continental ones are usually 16 amps).

If you’re using an extension reel, the cable may be thinner than is safe to use for an extended period at high load. That’s why they are sometimes fused at 10 amps. The plug fuse is there to protect the cable, and can be picked to protect something by limiting the load to less than the maximum a socket can supply.

If you’re using something that draws a sustained load at high amperage, 10 amps+ you really need proper fixed wiring to a socket, or at the very least a heavy duty reel, similar to what might be used on a building site and that should be unwound fully to prevent heat build up.

Normal extension leads are designed for light loads like gardening equipment, which are usually not drawing continuous loads and are often <5 amps.

The diameter of the metal conductors in the cable and the length of the reel dictate the safe load limit, not the plug or socket type.

Plug in something like a car charger or a heater and there’s a fairly significant possibility of melting the reel and even causing a fire.

Is there any model you recommend ? I bought one in the past for my electric lawnmower, I pick one with a thermal protection, should I look for something like this or is that just marketing ?

Something like this maybe, or this one which deliver to ireland ( i know the last one is 3Gang but I would only use one)

AutoTuning · 06-12-2020 3:17pm

I wouldn’t recommend it full stop tbh.

For a sustained high load, using domestic sockets and reels just isn’t safe. They’re just not designed for that use case.

kevincork · 06-12-2020 3:18pm

stimpson wrote: »

Using a heavy duty extension lead with a granny cable is not recommended. Using a splitter is a bad idea. If you were plugging in both cars on the same double socket then I think you are looking for trouble.

Either car will pull a heavy load for a long period of time so any issues with the wiring at all could cause problems (and by problems I mean your house could burn down)

I have a heavy duty (ie. rated for 13 amps and brand name) extension lead that I use very occasionally with my granny plug. I’m not giving advice here, but if I had 2 EVs and had to use extension leads then I would ensure they are both on different circuits (IE go back to different beakers on the fuse board).

Having said that, if I had 2 EVs I would install a proper charger and alternate them every night with a granny cable for emergencies.

And +1 on unrolling the cable every time. It will melt if you don’t.

I can ask my landload again , but he ignored when I mentioned on my last two email... well I can understand he don't want a EV charger install to be fair but yes that would be the dream solution.

If I use the extension lead, I would plug in inside the shed, which is a different circuit, (the other one would be in a outside plug in the front, but it's kind of scary, you can't very tell the quality, especially looking over on internet, I coud look at the co-op in west cork but I don't think they would have much better.

[Deleted User] · 06-12-2020 3:21pm

AutoTuning wrote: »

good brands like MK) !

MK are dirt now unfortunately.

kevincork · 06-12-2020 3:26pm

AutoTuning wrote: »

I wouldn’t recommend it full stop tbh.

For a sustained high load, using domestic sockets and reels just isn’t safe. They’re just not designed for that use case.

Ok thank you.

I'll ask my landlord again for an actual EV charger but I don't have much hope, otherwise I can get rid of the camera and plug and the granny charger directly into one plug

or last option, I can do what im doing at the moment, and basically drive to the back yard and plug inside the shed with a windows open, not very great though.

Anyway I think my landload is coming today, I'll ask them again.

Thank you for the advices.

AutoTuning · 06-12-2020 3:32pm

BrownFinger wrote: »

MK are dirt now unfortunately.

Some of their stuff is ok. Some is not what it used to be.

Just be aware of a couple of things about Irish/U.K. sockets. They’re physically huge, but that doesn’t equate to them being capable of carrying more power than other types.

They originally had no protective plastic sleeves on the pins, so to protect against shock from grabbing the pins when gripping a plug your fingers, the pins only make contact at the tips. This reduces the current carrying capacity a lot and can cause heating.

The other issue is the fuse holder is often just a brass spring holding onto a round fuse. If that makes poor contact, if they fuse is slightly out of line or the holder is distorted, the plug can get seriously hot.

In contrast CEE 7 plugs used in Germany, France etc etc insert into a recessed socket. This meant that the full 16 amps version doesn’t need sleeved pins and also can use much more of the surface area of the pin for contact. The result is they can usually comfortably carry higher loads. Your fingers are protected because the round body of the plug is has to fit into a round recessed socket, so live pins are never exposed at all. Only the very small, flat 2.5 amp euro plug for very small appliances used the sheathed pin approach.

They also contain no fuses or fuse carriers, so tend not to have heating issues. They’re a far simpler, more robust connector.

There are pros and cons to both designs, but I would trust a modern CEE 7 socket on a modern continental installation on a high load much more than I would a U.K. / Irish plug.

Realistically, for car charging you shouldn’t use domestic plugs and sockets at all.

Granny charger / multiplug

Comments