Can anyone help me with a bit of advice about the maximum current I can draw from an outdoor socket at home?
I have three 36V 30A isolated chargers that I want to use simultaneously to charge a 108V 60Ah battery pack. I'm hoping to keep charging time to two hours.
The chargers will draw 8A max. each, so 24A total. If possible I'd like to use a single socket installed outside so I can recharge while my car is on the drive. I already have a spare 30A (shower) supply with MCB from my distribution box.
I'd be grateful for any relevant advice, but what I'd specifically like to know is what maximum current I can legally and safely draw from a single outdoor socket, and if I can draw the full 24A from a single socket, which type of socket should I use?
I realise that the installation work would have to be done by a part P qualified electrician.
Maximum outdoor charging current?
Malcolm,
I think the challenge is finding a decent (and affordable) outside connector. I've wired the unused cooker outlet from my supply to a standard 16A industrial type connector, the normal blue three pin ones. I'm pretty sure that the cooker supply is rated for a fair bit more that the connector, but have fused it at 20 amps to be reasonably safe. Legally you must fit an RCD in the circuit, although at the moment I'm relying on the one built in to my distribution unit (which is probably not the best thing to do).
16A at 240V gives me around 3.8kW. Your three chargers are putting out a total of just over 3kW, so provided that their efficiency is greater than about 78% (which is quite probable if they are switched mode types) this solution should be OK for your purposes. You mention that they draw 8A each, which seems a bit high. This may well be just the initial surge current, or perhaps a fuse rating, as 8A input suggests a low efficiency of just 56%. Each charger would be dissipating around 900 watts of heat whilst charging if this was the case, and would be running very hot indeed.
16A three pin external sockets are readily available in places like B&Q and Wickes. I purchased an angled surface mount socket, with a spring loaded cover, for around a fiver, I think.
Hope this helps.
Jeremy
I think the challenge is finding a decent (and affordable) outside connector. I've wired the unused cooker outlet from my supply to a standard 16A industrial type connector, the normal blue three pin ones. I'm pretty sure that the cooker supply is rated for a fair bit more that the connector, but have fused it at 20 amps to be reasonably safe. Legally you must fit an RCD in the circuit, although at the moment I'm relying on the one built in to my distribution unit (which is probably not the best thing to do).
16A at 240V gives me around 3.8kW. Your three chargers are putting out a total of just over 3kW, so provided that their efficiency is greater than about 78% (which is quite probable if they are switched mode types) this solution should be OK for your purposes. You mention that they draw 8A each, which seems a bit high. This may well be just the initial surge current, or perhaps a fuse rating, as 8A input suggests a low efficiency of just 56%. Each charger would be dissipating around 900 watts of heat whilst charging if this was the case, and would be running very hot indeed.
16A three pin external sockets are readily available in places like B&Q and Wickes. I purchased an angled surface mount socket, with a spring loaded cover, for around a fiver, I think.
Hope this helps.
Jeremy
8A is the input current on the rating plate Jeremy, but I'm sure you're right that this is just the inrush current, as the chargers are switched mode and supposed to have an efficiency of 90% (Curtis HF3).
I realise I can probably get away with a 16A blue socket, but more than anything I was curious about the legal side and whether there are any other readily available outdoor sockets that are rated above 16A. I've not come across anything in my searching, but that doesn't mean they don't exist
I realise I can probably get away with a 16A blue socket, but more than anything I was curious about the legal side and whether there are any other readily available outdoor sockets that are rated above 16A. I've not come across anything in my searching, but that doesn't mean they don't exist
MalcolmB wrote:8A is the input current on the rating plate Jeremy, but I'm sure you're right that this is just the inrush current, as the chargers are switched mode and supposed to have an efficiency of 90% (Curtis HF3).
I realise I can probably get away with a 16A blue socket, but more than anything I was curious about the legal side and whether there are any other readily available outdoor sockets that are rated above 16A. I've not come across anything in my searching, but that doesn't mean they don't exist
Your quite right the do actually exist, try a 32AMP for size
ChrisB
I reject reality and substitute my own !!!!!!
Thanks Chris!
Most of those seem to have IP44 protection ratings, which makes them splash-proof (suitable for use in wet areas, if not sprayed directly). I suspect that's not good enough for an outdoor socket. Anyone know?
Looking around a bit more, there's a French company called Marechal that makes a whole range of industrial plugs and sockets that are rated to even higher currents and have IP67 protection. I've not found any prices yet, but don't expect them to be cheap.
Most of those seem to have IP44 protection ratings, which makes them splash-proof (suitable for use in wet areas, if not sprayed directly). I suspect that's not good enough for an outdoor socket. Anyone know?
Looking around a bit more, there's a French company called Marechal that makes a whole range of industrial plugs and sockets that are rated to even higher currents and have IP67 protection. I've not found any prices yet, but don't expect them to be cheap.
My 16A connector has been fitted to an outside wall for about 5 years or so now and seems fine. It's slightly sheltered by being under a window sill, but does occasionally get rain on it. Because the connector points downwards, water can't get in unless it were immersed or subjected to a hose/pressure washer. The cable gland at the top is well-sealed, plus I fitted the cable with a drip loop to stop water tending to run down the cable and rest on the sealing gland. Round cable works best, I used a length of cable intended for use underground.
I'm reasonably sure that IP44 is fine for use like this. A fully waterproof connector will be a lot more expensive, I suspect, and may not be as easy to use.
Jeremy
I'm reasonably sure that IP44 is fine for use like this. A fully waterproof connector will be a lot more expensive, I suspect, and may not be as easy to use.
Jeremy
Hi
Industrial or "CEE Form" or BS4343 plugs and sockets, as they are variously known, are available in 16, 32 and 63A versions readilly from any electrical supplier. They are supplied in Yellow (110v) Blue (230V) and Red (400v) cheap and cheefull from Gewiss (Itallian) or from german makers such as Mennekes or fly the flag and buy Lewden! They are available in standard IP44 and also IP65 versions with locking collars.
IP44 fine for most outdoor use but if you tend to jet wash everything then use IP65!
If you look at a catalogue of these connectors you will also find 125A versions and versions for other volages and frequencys including natty purple ones for 24V!
You wont get most of them from Aldi or B&Q though.
Industrial or "CEE Form" or BS4343 plugs and sockets, as they are variously known, are available in 16, 32 and 63A versions readilly from any electrical supplier. They are supplied in Yellow (110v) Blue (230V) and Red (400v) cheap and cheefull from Gewiss (Itallian) or from german makers such as Mennekes or fly the flag and buy Lewden! They are available in standard IP44 and also IP65 versions with locking collars.
IP44 fine for most outdoor use but if you tend to jet wash everything then use IP65!
If you look at a catalogue of these connectors you will also find 125A versions and versions for other volages and frequencys including natty purple ones for 24V!
You wont get most of them from Aldi or B&Q though.
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