Granny charger fire warning

[dragon2611]

Given the control protocol has the ability to specify charging currents down to 6A and the cost of even the portable EVSEs (Granny chargers) I really don't see why they're not all adjustable down to 6A (Infact this should really be the default and you should have to select 8 or 10A) as surely the electronics to support selecting charge client add maybe at most a couple $ to the cost of the thing.

I carry a Hyundai one instead of the MG one the car came with explicitly because I wanted this feature.

Other than a quick test when changing cars/chargers to make sure they work I've only actually used the granny chargers a handful of times and that was when I got my first EV and when on holiday miles away from the nearest charger. (Even then I noticed charging at 10A made for a slightly warm socket and changed to a different one as well as dropping to 6A)

 

[AK OK]

15 year old socket? Say no more. Glad the damage was limited.

When was it last all inspected, tested & tightened up?

Just to add that while 2.2kw is well within spec, 2.2kw for 10 hours straight can build up some serious heat in a junction. Said junction box had been subject to 15 years of heating and cooling from weather, possibly vibration as well and perhaps a screw hadn't been tightened quite enough originally.

Or on any inspection since... That's why you can't hide these things... "Accessible" is da word, to allow inspections & testing.

If you want to hide it &/or forget about it use appropriate wagos in a wago box simples

View attachment 12375View attachment 12376
Since we purchased our MGZSEV a year ago we have used the MG supplied granny charger plugged into our carport 3pin 13amp socket for most of its charging.

Recently whilst charging the power to the socket failed & on investigation we found that the other 2 sockets on that ring main were also dead.

Eventually we found a burnt out junction box in the roof of the carport which was a professionally built house extension of some 15 years. As far as we know the wiring had been installed by a qualified electrician. The carport circuit was taken off the existing upstairs ring main of 4x13 amp sockets back to an old fashioned 30amp fuse as originally installed some 45 years since.

In theory the circuit should have been ok as 30amps will give 7kW of power, the granny charger taking 2.2kW plus say a hoover at 1kW plus say a fan heater at 2kW total 5.2kW. However there are several factors that make this assumption erroneous. Firstly the granny charger will take 2.2kW continuously for many hours unlike a hoover for 1/2hr & a fan heater on & off. Therefore any heat build up in the circuit will not readily dissipate until charging ceases. Secondly we estimated that the length of wire from the charger socket back to the fuse box was over 100ft or 30mtrs which would give some voltage drop thereby increasing the current required by the charger. Thirdly we don’t know how well or badly the wires were joined in the junction box & at other places.

I show pictures of the burnt junction box & think we were lucky not to have had a serious house fire. There were scorch marks on the nearby wooden floor joist but I think luckily any flames were subdued by the fibreglass insulation.

And the fact that even at that age the junction box was made of non flammable /fire retardant material - did it smell like rotten fish?

The problem you had (I surmise) is the terminal screws in that box had worked loose or were never tight. Eventually tiny arcs became bigger arcs all along heating up the cable & the junction box in which the terminals are located.

I'd be thinking to get a sparky round & see what happens... Old style fuses? RCD? Flaky junction boxes? Lucky it was outside really, rather than inside under the floor, though they do stink when they get too hot so that would be your first clue unless you have kippers every day

 

[pollenface]

I really don't see why they're not all adjustable down to 6A (Infact this should really be the default and you should have to select 8 or 10A)

I have a generic one I bought off ebay ($300aud), it can be set to 6/8/10/15 and it keeps the last setting even after being turned off. If set to 6 last time it was used, it will be 6 next time we turn it on.

 

[timeades]

I'm not an electrician, but white PVC cable coming out of a junction box going to sockets? Surely that's not right?

Anyway, glad I ran a dedicated run for my granny socket after seeing this.

15 years ago it probably was right

 

[AK OK]

Expensive but probably the best off the shelf.

EV granny charger 13A weatherproof extension lead

High quality 13A weatherproof outdoor waterproof extension leads heavy duty 1.5mm H07RN-F rubber cable. RCD option. IP66. Designed specifically to overcome the issue created by chunkier plugs on electric vehicles (EVs). 2m, 5m, 10m, 15m, 20m and 25m lengths.

toughleads.co.uk

Interesting...

"Please note that RCDs are active units, which means that the reset button must be pressed each time the power is reconnected. They will therefore not function if plugged into a socket controlled by a timer."

Is that all RCDs or their RCDs?

 

[mj224]

I used a Granny Charger for several years with my little Citroen Zero. Three plugs and one socket warmed up enough to be changed. I would not have got away with it with a bigger battery and longer charging times. and that was with modern wiring....

 

[AK OK]

I used a Granny Charger for several years with my little Citroen Zero. Three plugs and one socket warmed up enough to be changed. I would not have got away with it with a bigger battery and longer charging times. and that was with modern wiring....

Three plugs?

 

[Alb]

Interesting...

"Please note that RCDs are active units, which means that the reset button must be pressed each time the power is reconnected. They will therefore not function if plugged into a socket controlled by a timer."

Is that all RCDs or their RCDs?

Just the ones that they are talking about.
I have an old plug in RCD that works this way.

 

[AK OK]

Just the ones that they are talking about.
I have an old plug in RCD that works this way.

Mmm so given the likely usage that sounds a bit limiting? May be put the timer after another RCD & not take theirs?

 

[Alb]

Better to upgrade your whole system if it isn't already RCD protected. I had a new RCBO CU fitted when my HyperVolt was installed and the total cost still fell under £1k.

 

[AK OK]

Better to upgrade your whole system if it isn't already RCD protected. I had a new RCBO CU fitted when my HyperVolt was installed and the total cost still fell under £1k.

Can't really insist on a rewire when visiting elsewhere & plugging into their cooker socket though? Which is where I thought this came in....