What limits how much you can run off an extension chord?
Discussion
I'm finally getting around to setting up my office room - just the 12 months after finishing the renovation of the house.
Of course, I'm now realising I should have had one or two more sockets added to that room, as is always the way.
As it stands it looks like I'll need to use two extension cords on a double socket, with one cord having about 4 things plugged into it, and the other cord with about the same.
So basically 8 things running off one double socket. Is this ok? I've never quite understood what makes it so important to have everything running off actual sockets rather than cords like this, but I'm sure there's a very simple answer.
Of course, I'm now realising I should have had one or two more sockets added to that room, as is always the way.
As it stands it looks like I'll need to use two extension cords on a double socket, with one cord having about 4 things plugged into it, and the other cord with about the same.
So basically 8 things running off one double socket. Is this ok? I've never quite understood what makes it so important to have everything running off actual sockets rather than cords like this, but I'm sure there's a very simple answer.
Edited by UTH on Friday 6th January 11:48
CrutyRammers said:
It's all about the total current draw. As long as everything on an extension cord doesn't exceed 13A, it'll be fine.
For most domestic things these days, that would be unlikely, unless it's something like a fan heater, kettle, electric drill and iron all running together
Ahh ok yeah I was thinking along those lines, avoid a heater, kettle etc and it'll be fine. For most domestic things these days, that would be unlikely, unless it's something like a fan heater, kettle, electric drill and iron all running together
So I'll be ok, it's just things like a printer, laptop charger, screen etc
Cheers.
For me it’s down to a BS1362 fuse (Ie 13A) doesn’t “blow” at 13A
It can sustain 25A for 30 mins before it goes or about 60A for 5 seconds.
Although you probably won’t have many 13A loads, depending on characteristics, you could potentially exceed the current rating of the extension / plug / socket. (potential fire)
Also, there’s the whole historic thing of unfused multi-way adaptors which could easily exceed rating of the socket / pins of adaptor.
It can sustain 25A for 30 mins before it goes or about 60A for 5 seconds.
Although you probably won’t have many 13A loads, depending on characteristics, you could potentially exceed the current rating of the extension / plug / socket. (potential fire)
Also, there’s the whole historic thing of unfused multi-way adaptors which could easily exceed rating of the socket / pins of adaptor.
If you are running anything pokey current wise unwind the extension (or buy one that is the right length when fully unwound)
I welded the plastic casing of the cables together in the cable still wrapped around the extension reel running a 2 500W floodlights for illumination under my floor while I was doing an insulation project
I welded the plastic casing of the cables together in the cable still wrapped around the extension reel running a 2 500W floodlights for illumination under my floor while I was doing an insulation project
B'stard Child said:
If you are running anything pokey current wise unwind the extension (or buy one that is the right length when fully unwound)
I welded the plastic casing of the cables together in the cable still wrapped around the extension reel running a 2 500W floodlights for illumination under my floor while I was doing an insulation project
Ahh yes good shout, will make sure it's not a load of wound cable. I welded the plastic casing of the cables together in the cable still wrapped around the extension reel running a 2 500W floodlights for illumination under my floor while I was doing an insulation project
As has been said the limit is the current draw which is limited to a maximum of 13A per strip (& 20A total from a double wall socket) but that shouldn't be an issue if you are just using ordinary PCs, screens, printers etc. I screwed six way strips to the back of my desk which keeps everthing a bit tidier.
I'd make sure to buy decent brands though - don't settle for the cheapest Chinese tat from Amazon.
I'd make sure to buy decent brands though - don't settle for the cheapest Chinese tat from Amazon.
Mr Pointy said:
As has been said the limit is the current draw which is limited to a maximum of 13A per strip (& 20A total from a double wall socket) but that shouldn't be an issue if you are just using ordinary PCs, screens, printers etc. I screwed six way strips to the back of my desk which keeps everthing a bit tidier.
I'd make sure to buy decent brands though - don't settle for the cheapest Chinese tat from Amazon.
Cool I was thinking of doing exactly that to keep things tidier as it sounds like there's no reason it can't be my permanent solution I'd make sure to buy decent brands though - don't settle for the cheapest Chinese tat from Amazon.
The maximum you can run of any single UK household socket is 13A, which is 3KW.
As an aside, double sockets are not usually rated at 26A. They are more like 20A, so 13A on one socket & 7A on the other, or two 10A appliances. You should not plug two 3KW appliances into a double wall socket.
The amount of current you can draw from an extension lead are limited by the thickness of the cable itself. It is possible to buy cheap extension cables that are only rated at 5A. If in doubt, check the fuse fitted to the lead's plug.
If plugging multiple appliances into one extenstion lead, add the current drawn by each device together and ensure the total does not exceed the capacity of the lead. There is no limit to the number of devices that can be safely powered, it's the total current drawn that is the limiting factor.
As an aside, double sockets are not usually rated at 26A. They are more like 20A, so 13A on one socket & 7A on the other, or two 10A appliances. You should not plug two 3KW appliances into a double wall socket.
The amount of current you can draw from an extension lead are limited by the thickness of the cable itself. It is possible to buy cheap extension cables that are only rated at 5A. If in doubt, check the fuse fitted to the lead's plug.
If plugging multiple appliances into one extenstion lead, add the current drawn by each device together and ensure the total does not exceed the capacity of the lead. There is no limit to the number of devices that can be safely powered, it's the total current drawn that is the limiting factor.
As said, almost all office stuff will be absolutely fine and very low draw.
Computers, laptops, screens, network switch etc all use almost nominal amounts.
Laser printers can pull a bit more, maybe 1kW but unlikely to upset the works given you limit is around 3kW.
Kettles can be 2 or even 2.4kW but also really quite low duty cycle, so again likely actually to be ok all most certainly. Ditto vacuum cleaner.
At which point the only real issue is likely to be if you stick a 2kW+ heater on there, which will suck close to your 3kW broadly continuously.
The only time I have ever had a socket melt is when I was running my whole garage of a single 13A socket in the conservatory for a while, and had a 2.6kW heater on there, along with a few other small and intermittent loads. Lasted about four hours.
Tumble driers can be the other long-duty consumption device.
Computers, laptops, screens, network switch etc all use almost nominal amounts.
Laser printers can pull a bit more, maybe 1kW but unlikely to upset the works given you limit is around 3kW.
Kettles can be 2 or even 2.4kW but also really quite low duty cycle, so again likely actually to be ok all most certainly. Ditto vacuum cleaner.
At which point the only real issue is likely to be if you stick a 2kW+ heater on there, which will suck close to your 3kW broadly continuously.
The only time I have ever had a socket melt is when I was running my whole garage of a single 13A socket in the conservatory for a while, and had a 2.6kW heater on there, along with a few other small and intermittent loads. Lasted about four hours.
Tumble driers can be the other long-duty consumption device.
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