Thread: Electric Motor Trips Circuit Breaker

Are you sure the bakelite switch is wired correctly?
Sometimes the active and neutral are wire incorrectly.

I would definitely upgrade the switch and use a no-volt switch - something like this should do it.
http://www.ebay.com.au/itm/5-Pin-DPS...f199640&_uhb=1

I would assume the switch is wired correctly as it was taken directly off the previous motor.

Is the 10amp powerpoint enough for this motor?

Originally Posted by DSEL74

I would assume the switch is wired correctly as it was taken directly off the previous motor.

Not necessarily. I refurbed a machine at the mens shed a few months ago that had the active and neutral switched over at the switch and then switched back again at the motor.

Is the 10amp powerpoint enough for this motor?

Provided nothing else is running anywhere on the circuit it should at least start/run on a 10A circuit, nut ong term it's better to have it on a 15A circuit.
It's also likely to trip out a 10A an expansion board with a breaker on t.

Nothing else is on circuit. I'm waiting on a quote from a sparkie for some 15am points but need to use saw before then. Here are some more pics if they help

230 Volts and 2.2 KW says 9.5 or 9.6 amperes.

With the motor running, a 10 Ampere circuit is barely adequate. Start up current is going to be close to 12 Amperes.

A little bit different here but principals are the same. My Delta cabinet saw, 3HP motor uses a 230 Volts and a 30 Ampere circuit. (Per manufacturer's requirements.) We don't specify KW on much of anything except heating elements. (Space, pool, cooking appliances, etc.)

I'm unfamiliar with your terminal nomenclature. I assume that U1 and U2 are the inputs.

The only thing that I can think of is to reverse the connections to U1 and U2. I see words like "neutral" which, here in the US, is electrically a ground. (My Delta is wired using an L1 and L2 to get the 230 volts. Neutral is there for the magnetic switch.) Our normal / consumer electricity is 115 Volts using either L1 or L2 to Neutral. L1 and L2 are the opposite sides of the phase.

My thinking is that your motor is internally wired to be used in a 230 Volt to Neutral environment. So if your power cord has a ground wire and you happen to have the "wrong" side connected to the hot wire then when you hit the switch, you are connecting hot to ground and the breaker will trip instantly.

If you have a meter check for a short from either U to the case of the motor. The one that is almost zero Ohms is probably neutral.

Hi,
If it is tripping instantly it is likely to be an earth fault. It may be damp or something like that.
Regards

I wired a new length of flex direct to motor no switch and she runs.. So either the old flex has been damaged since it was last run with old motor or the switch was the issue.

I'll get a new switch like the one linked to above, and after the sparkie comes will have a 15Amp plug fitted. At least now (hopefully) I can get through cutting all the gal fence posts before the dog gets out.


Thanks for all your input guys

Originally Posted by DSEL74

I wired a new length of flex direct to motor no switch and she runs.. So either the old flex has been damaged since it was last run with old motor or the switch was the issue.

I'll get a new switch like the one linked to above, and after the sparkie comes will have a 15Amp plug fitted. At least now (hopefully) I can get through cutting all the gal fence posts before the dog gets out.

Thanks for all your input guys

good to se you have sorted this out.

I'll keep an eye on this one have a belt/disc sander doing the tripping of power ATM not constantly tho.

Hi. I noticed that your circuit breakers are actually 20A and you motor is rated just under 10A. I believe you should be fine using that motor on a 10A circuit and the starting current is well within specs of your 20A circuit breaker. So technically all is well. A 'normal' tangi heater and many electric kettles are actually 2.4kW - and are fine plugged into a 10A socket.
But please do ask your sparky for the correct legal opinion. The electrical regs may have other things to say about inductive loads.

I understand the need to fiddle with things, to make, to fix. This forum is bound to attract just such people. That is what we do.

But there are limits to this and playing about with electricity is one of them. Electricians spend years learning how to safely work with mains power. Even then sometimes people get hurt but we amateurs are just risking our lives and the lives of anybody else who comes near if we try to mess with this sort of thing ourselves.

It is just not worth the risk.

Originally Posted by chook

I understand the need to fiddle with things, to make, to fix. This forum is bound to attract just such people. That is what we do.

But there are limits to this and playing about with electricity is one of them. Electricians spend years learning how to safely work with mains power. Even then sometimes people get hurt but we amateurs are just risking our lives and the lives of anybody else who comes near if we try to mess with this sort of thing ourselves.

It is just not worth the risk.

Not only does this forum "attract just such people" - it is actually ENTIRELY for such people. I don't think anyone else looks at this forum....

Well, some of us 'amateurs' have spent decades learning how to safely work with all sorts pf power. I know you won't like it, but there are quite a few people here who actually know a LOT more than the average electrician - I'm not saying that I may be one of them, but I personally know quite a few forum members who are. (I have wired up 4 houses completely - with registered contractor supervision - and all passed inspection and are on mains power. The first one for 40 years this year. Just sayin'). Don't just judge carefully worded information provided here as "playing with electricty".

Hi,
What one has to remember when giving advice to the can do members of this forum is that although you can form an impression of the ability of the person asking, you have no idea of what Dick Head may be taking the advice. People Google and end up reading it, they can be any where in the World and using any system. I have seen posts where some one wanting to do work in an Australian shed had been doing his research on an American "how to" site he did not even know the electrical terms or that the system and regulations are different.
The more you know about some thing, the more you realise there is more to know. Electricity has a natural way of dealing with the "Know it all know nothing"
types

2dworth.jpg

I am sure that there are people who are not qualified electrical contractors who have some knowledge of how to wire up and repair electrical equipment. The people involved in giving advice in this thread may be some of them. There are some smart people about.

I suppose if you want to wire up your own machinery, house or shed you can take your chances with your life. You know yourself better than anybody else.

But I hope that if anybody ever sells me any electrical equipment, invites me into their house or shed to use any electrical equipment they have repaired themselves that at least they tell me first so I can make the decision as to how much of my life I want to put into their hands.