Check your Granny!

[Paulie68]

This may be of interest to us all...

Due to the wife's car being in the way and as I'm too lazy to swap things around, I'll often just pop my car on the 13A outside socket and granny charge it rather than use our 7kW point.

I've done this maybe a total of 20 times over the last 7 months. As the car has usually finished charging when I unplug it, I'd not noticed until the other day that the plug gets immensely hot and has heat damaged the socket outlet.

I assumed this was down to the socket being a cheaper brand, British General. So changed it out for a Schneider that cost 3 times more! An hour later, checked it and the plug and socket are scalding hot!

So I autopsied the cheap socket, and found it was actually fine, contacts are still all like new and don't look like the source of the heat build up. The heat is coming from the Live pin on the moulded plug, so I suspect there is a high resistance connection in the plug.

I've yet to do it, but I'm going to cut off the moulded plug and fit a quality replacement. I'll do an autopsy on the moulded plug to see what the issue is and report back. In the meantime, be careful when using you grannies! Keep an eye out for any heat build up.

Piccies:

Heat damaged faceplate

But the contact surfaces in the socket are very good, the issue seems to be caused by Grannies plug

 

[kiltox]

Some chargers have a temperature sensor in the plug - I’m guessing the MG one doesn’t - but cutting the moulded plug off often creates issues there

 

[MEH]

I have had endless problems with moulded plugs in the past and replace them on everything I get that has one

 

[Phil Hayward]

Sometimes the fuse holder is not gripping the fuse tight enough, rivetts are another problem.
When I worked as an electrician we fitted MK plugs for high loads like electric fires.
The charger isn't a Charger, its just a relay to connect the power when told to, A lot of money for simple device.

 

[Paulie68]

Just had a look at the plug, yep, it's the fuseholder. Phil is bang on, the crappy pressed rivet holding one end of the fuse holder contacts in the plug is loose!

I suppose I could ask for a new one under warranty, but then, that's going to have the same crappy design in the plug, so I'll probably just change the plug.

 

[Paulie68]

Some chargers have a temperature sensor in the plug - I’m guessing the MG one doesn’t - but cutting the moulded plug off often creates issues there

Should be no issue if done right with a quality plug, properly fitted. Clearly there's no temperature sensor on our granny plugs!

 

[Paulie68]

Here's the culprit, the fuse holder circled has a loose rivet causing high resistance and huge heat build up and transfer down the Live pin!

 

[Kithmo]

Here's the culprit, the fuse holder circled has a loose rivet causing high resistance and huge heat build up and transfer down the Live pin!

View attachment 710

That's not good for a piece of equipment that is supposed to be able to take a continuous 9 or 10A for 12 hours.

 

[Paulie68]

That's not good for a piece of equipment that is supposed to be able to take a continuous 9 or 10A for 12 hours.

No it's not. If anyone else has a similar issue, this plug is a very good quality replacement.

Essentials 13A Fused Heavy Duty Plug Black - Screwfix

Order online at Screwfix.com. Durable and hardwearing. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

Looks right once fitted as well:

 

[viking]

This may be of interest to us all...

Due to the wife's car being in the way and as I'm too lazy to swap things around, I'll often just pop my car on the 13A outside socket and granny charge it rather than use our 7kW point.

I've done this maybe a total of 20 times over the last 7 months. As the car has usually finished charging when I unplug it, I'd not noticed until the other day that the plug gets immensely hot and has heat damaged the socket outlet.

I assumed this was down to the socket being a cheaper brand, British General. So changed it out for a Schneider that cost 3 times more! An hour later, checked it and the plug and socket are scalding hot!

So I autopsied the cheap socket, and found it was actually fine, contacts are still all like new and don't look like the source of the heat build up. The heat is coming from the Live pin on the moulded plug, so I suspect there is a high resistance connection in the plug.

I've yet to do it, but I'm going to cut off the moulded plug and fit a quality replacement. I'll do an autopsy on the moulded plug to see what the issue is and report back. In the meantime, be careful when using you grannies! Keep an eye out for any heat build up.

Piccies:

Heat damaged faceplate

View attachment 706

But the contact surfaces in the socket are very good, the issue seems to be caused by Grannies plug

View attachment 707Thanks for taking the time and trouble to explain all this Paul. Wonder how many potential disasters will be avoided thanks to your efforts?!

 

[micky]

No it's not. If anyone else has a similar issue, this plug is a very good quality replacement.

Essentials 13A Fused Heavy Duty Plug Black - Screwfix

Order online at Screwfix.com. Durable and hardwearing. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

Looks right once fitted as well:

View attachment 711

I can remember when i was young and the plugs were bakelite and they had the same issue but due to the burning out issue use to smell fishy and then just broke up into pieces,looks like we have done a full circle..

 

[macd2401]

I checked on my grannies the other week, and I can confirm they're both in their coffins, where we left them... dunno about the charger though ??

 

[Kithmo]

I can remember when i was young and the plugs were bakelite and they had the same issue but due to the burning out issue use to smell fishy and then just broke up into pieces,looks like we have done a full circle..

When I was a kid, plugs were Bakelite with round pins.

 

[Paulie68]

When I was a kid, plugs were Bakelite with round pins.

The larger 15A version of that never went away! Usually used in theatres and exhibition type places, it's superior to the 13A we have now and can maintain 15A indefinitely, not fused, so can only be used on dedicated circuits and doesn't have the child/idiot proof shutter mechanism, so can't be used in your house

readily available too:

Schneider Electric Lisse 15A 1-Gang SP Switched Round Pin Plug Socket White - Screwfix

Order online at Screwfix.com. Moulded round pin plug socket. Durable, high quality urea construction with antimicrobial properties. Supplied with four screw cap covers for a sleek finish. Ideal for new construction and refurbishment projects. FREE next day delivery available, free collection in...

www.screwfix.com

Electrical Plugs | Electrical Plugs 3 Pin | CEF

Buy plug tops now from CEF, the UK's largest electrical wholesaler. Free next working day delivery on orders over £50

www.cef.co.uk

 

[Alb]

I have a box full of old 13A plugs at home and it's interesting to see the diversity of design around the fuse carrier. It's very clear that some designs are far better suited to high current applications than others.

 

[LarsJensen]

The European Schuko plugs are approved for 16 Amps.

16A Plug 250V IP44 European Type E & F German and French Dual Earth PCE 0521-S

PCE European Plug, suitable for use throughout Europe at the plug has Dual earthing systems for both German Austria Types & French Belguim Types Black 16 Amp European French Plug, 3 Pin, 250V, IP44 by PCE – Essential Supplies – 01752 817 140

www.essentialsupplies.co.uk

 

[Alb]

If you went down this path, better to use the UK one I'd have thought?

Industrial Connectors IP44

If you need to make connections between two cables carrying a high-power or high-current supply of electricity, consider this industrial connector. You can use it in settings such as camping, caravanning or when you're charging electrical devices. Because this is an IP44 rated plug, your...

www.toolstation.com