Lets talk about electrical load ratings

[Mc lovin]

I can tell you opened this after reading the title and thought, well this'll make for and interesting thread, probably one of the most interesting on here, and you'd be right

can someone tell me the average load rating per single phase twin socket, used by say light power tools.

Also the same question for x6 fluorescent lights?

[Mc lovin]

oh and also what is the usual starting method for a three phase electric motor, for something like a proper table saw etc? what would the starting current be on a motor rated at 1.1kw?

[Brite spark]

Mc lovin said:

can someone tell me the average load rating per single phase twin socket, used by say light power tools.

Also the same question for x6 fluorescent lights?

The largest fuse you can get for a domestic plug is 13A, sockets will be rated to this in terms of the load they will be able to switch from the faceplate, although the socket may be on a 20A radial or 32A ring main, so current in the circuit may be higher.

I =

P
__
V

Current I (Amps)=

Power P (Watts)
_________________
Voltage V (Volts)


Therefore to use 13A at a socket

3000w-3kw = 13A
______

230

Not really that common apart from heaters


Light power tools ie drill

700

230 = 3A


assuming 6 6ft twin luminaires with 70 watt tubes

140 w per light fitting x 6 fittings =840w

840
___
230 =3.65A

allowing for start up current using stated factor for discharge lighting where figure is unknown

3.65 x 1.8 = 6.57A At start up (worst case)

Mc lovin said:

oh and also what is the usual starting method for a three phase electric motor, for something like a proper table saw etc? what would the starting current be on a motor rated at 1.1kw?

probably soft start (dol) for something like a table saw, though not something I deal with and there are certainally other ways to do it

Edited by Brite spark on Wednesday 7th October 19:53

[Mc lovin]

top stuff, thanks very much for this