On a radial socket circuit how can you be sure what MCB and cable size to use when you can't be sure what appliances are going to be used on it i.e. How do you know that the appliances won't overload the cable and trip the MCB?
You don;t. You use your best judgement and experience in most cases. When you design a circuit you design it for expected use, so if you were to put a 16A radial in a living room of a modern house with central heating etc.. then you wouldn;t expect it to be overloaded with a TV, stereo and a couple of lamps. If someone then plugs in 4 3kw heaters this would be too much for the circuit but it wouldn't be expected.On a radial socket circuit how can you be sure what MCB and cable size to use when you can't be sure what appliances are going to be used on it i.e. How do you know that the appliances won't overload the cable and trip the MCB?
I know a lot of sparks are going for radials these days but I am old fashioned.Batty
correction to the above....On a radial socket circuit how can you be sure what MCB and cable size to use when you can't be sure what appliances are going to be used on it i.e. How do you know that the appliances won't overload the cable and trip the MCB?
thats the max load of the appliances- in reality, they wont use that power all the time. the 2KW kettle will use 2KW whenever its on. the iron may use 1kw whilst heating, but will switch off when hot and come back on when cooler. the w/m has a heater which will heat the water, then turn off - so there is unlikely to be the 5.5KW for long durations. they may all overlap every so often, but it shouldnt be a problemThanks for your help guys. Can you help me with this scenario though:Say a radial socket circuit is wired using a 2.5mm T&E with a 20A MCB (which I believe is common). An iron (1 KW), a kettle (2KW) and a washing machine (2.5KW) are all plugged in on this circuit and are being used at the same time. That's 5.5KW (for argument's sake). Using W = V x I that would leave a current of 24A which would be enough to trip the MCB yet it's not uncommon for these appliances to be used at the same time. So, how can 2.5mm T&E be seen as being suitable for radial socket circuits?
I'm not trying to be a smart-ass asking this, I just don't understand it!
Get a genny in cheapest option.I have had to do a rethink or should I say a reinstall because when I did a commercial installation earlier this year the kitchen onlt had a washing machine and a kettle and one microwave. After installation I found out that at lunch times they had two kettles 4 microwaves, the washer and a portable heater all on the go at once.My circuit would not handle everything so I have had to go back and beef it up for the occasional 20 minute demand.
[quote name='AndyKettles draw maximum current just as they are coming to the boil.
Yep, but the heater will generally be 1200W, maybe up to 2000W on some older machines, so not an overly high load.Hmmm. Pump usage is negligable, IMO. Drum rotation is generally only a sizeable load whilst spinning; during which time the heater is obviously off. If asked, I`d have said that the heating cycle was the main issue.Though I stand to be corrected...........
KME
Mine doesn't. Mine uses the same number of amps throughout the cycle. I can verify this from a little gadget I got from MaplinKettles draw maximum current just as they are coming to the boil.
I haveI've never checked the current draw on kettles.
If you were to heat a volume of water with a steady heat source, you would observe that each rise of one degree in temperature would take the same amount of time, until you reached boiling point. Depending upon how much heat is applied, the time taken to go from 99
Enter your email address to join: