Thread: Do I really need a 15 AMP plug

Goes without saying

Hi Bob,

i last measures about a year ago. Might stick my metre in a socket tonight and take another look

The safest thing to do is get an electrician in to advise you!
Some important points that haven't been made yet are...

• a "15 amp plug" is a mechanical device to ensure that it can only be plugged into a 15amp circuit. It has nothing at all to do with the plugs capacity to the job it is only to make sure that you plug into a 15amp circuit.
• calculating the current drawn by a motor is pointless if you only look at the full load current. At the time of starting, and depending on the type of motor, the current drawn can be up to 5 times the full load current
• AT THIS POINT IN TIME all Australian networks supply at 240V with a tolerance that can be +3%/-6% (225V to 248V) and the utilities in some states suffer pretty substantial penalties if supply is outside that range BUT......
• the standard voltage in Europe is now 230V (and I think subject to +3/-3%, 223V to 236V) and there are a number of utilities and regulators looking at changing our standard to match
• So, if you have calculated 6 amps at full load, at start up it COULD be 30amps and, if you start your dust collector at the same time, you can very quickly be drawing 40 amps!

The moral of the story is to get a sparky to look at it for you AND it is always good practice to NOT connect your machine and the dustcollector to the same switch and start at the same time.

fletty

Have ya got a file?

Fletty, Sydney is now 230V +/-

Originally Posted by Pat

Fletty, Sydney is now 230V +/-

... but it's supposed to be a SECRET ?

fletty

The voltage will vary at your premises according to the load at various times of day. Just check how long a pot of water takes to boil when every one in the street is cooking and at off peak times.
Regards

Originally Posted by nrb

Can you please explain a bit more about this,thanks

Back pressure I mean??

The higher the mains V the more energy a Photovoltaic system needs to generate put power back into the grid - this means the electrical authorities can then pay photovoltaic power generates a bit less less for their power.

I have current and voltage meters that I can move around and check what the start up and running currents are on with all my appliances and machines.

The most monitoring I have done are on my table saw, 2HP and 3HP DCs, A 2HP (19") BS, and a bunch of other fans and power tools,
The start up currents I can see on my monitoring gear are only small snapshots of what is going on while the devices start up and in actuality will be even higher than what I describe.

The the highest start up currents the BS and DC show for a brief period are ~35A and 25A respectively.
For both machines it takes about 3 seconds for the current to settle to a free running current of 6 A.
The BS and DC have been connected to the same 10A GPO and a 15A breaker circuit and they run fine.
They also run from an expander board with a 10A breaker without tripping.

Of course other DCs and BS may vary.

Originally Posted by rod1949

Have ya got a file?

249 volts confirmed

Originally Posted by Damienol

249 volts confirmed

We had that today as well, haven't seen it this high for a while.

Good discussion. I'm about to get in a sparky to discuss upgrading the shed. I'm popping fuses.

Time to dig out the volt-o-matic and check my peaks.

This place has old wiring, no doubt done on the cheap.

I had a chat to a Sparky and as the mancave is wired with 4mm instead of the usually 2.5mm I can replace the current 20A CB with a 32A CB


This should keep me out off trouble for a while.