Electric motor - advice needed

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geekIT

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#146619 23-May-2014 20:18

My bench grinder is built on an elderly 1\4 HP motor.

One of the wires (rubber coated) that connect the stator to the internal terminal board shorted out, probably when I shifted the grinder to a new location.

My solution was to open the case, remove the rotor and try to splice in a new section of wire.

Problem is, I can't access the wiring from the withdrawn rotor end because it's hidden behind the stator, and I can't quite reach it from the terminal board end.

I can't see any way to withdraw the stator, in fact it looks as though it's permanently fixed to the inside of the case.

Anyone able to help me with this, or point me at some info for this motor?

Details on the name plate are:
A.C Motor BS2408
Associated Electrical Industries
Spares no. D34043
Insul. Class E
Single Phase 50 c/s
1/4 HP (difficult to read - could be 1/2 maybe)
A - 2.3
1425 RPM
BS 170

Note: I don't think the windings have burnt out; it's that one of the very old wires shorted to the case and destroyed around 20mm of wire.

Thanks :-)

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#1051894 23-May-2014 20:25

I can't imagine there is no way to get the stator out in a motor of that vintage... you just need to try and figure out how it's done.

gregmcc

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#1051938 23-May-2014 21:10

No point harping on about the legalities of electrical appliance repair and requiring a suitiable class of registration and practicing license.......but for 1/4 HP it quicker and easier to got and buy a new one, they arn't that expensive

Fred99

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#1051987 23-May-2014 22:36

gregmcc: No point harping on about the legalities of electrical appliance repair and requiring a suitiable class of registration and practicing license.......but for 1/4 HP it quicker and easier to got and buy a new one, they arn't that expensive

What legalities?
You can fix your own electrical appliances - so you're right. No point harping on implying that you cam't.

gzt

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#1051995 23-May-2014 22:52

These legalities:

New Zealand Electrical Code of Practice for Repair and Maintenance of Domestic Electrical Appliances by the Owner of the Appliance (NZECP 50:2004).

Fred99

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#1051997 23-May-2014 23:00

gzt: These legalities:

New Zealand Electrical Code of Practice for Repair and Maintenance of Domestic Electrical Appliances by the Owner of the Appliance (NZECP 50:2004).

Cool. These state:
You can fix your own electrical appliances - so you're right. No point harping on implying that you can't.
In particular that it's "requiring a suitiable class of registration and practicing license" when it doesn't.
The link provides some guidance to how such DIY work must be carried out. All good.

gregmcc

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#1052033 24-May-2014 05:08

a grinder motor hardly falls within a "domestic appliance", this is some you would find in a workshop not a kitchen

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#1052047 24-May-2014 08:39

geekIT: I can't see any way to withdraw the stator, in fact it looks as though it's permanently fixed to the inside of the case.

Apparently it's a close fit in the outer case and held in place by the end caps. If it isn't rusted in it should respond to a tap. Google AEI motor, there's a relevant post on a hobby forum.]

Sidestep

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#1052048 24-May-2014 08:43

Surely a small plug in device like a ¼ hp grinder is a domestic appliance?

What's the definition?

I understand and agree with the intent of the law, but fixing small things at home can't be illegal?

This week I've replaced the water level sensor on a washing machine, and the wire feed unit on my small mig. Both were extremely simple non-technical things to do.

I also replaced the pressure switch/unloader on my large 2 phase, hard wired compressor, also a basic job, but bowing to the letter and intent of the law, had a mate (who's a Sparky) check it out before I put the cover back on.

gregmcc

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#1052053 24-May-2014 09:06

Sidestep: Surely a small plug in device like a ¼ hp grinder is a domestic appliance?

What's the definition?

I understand and agree with the intent of the law, but fixing small things at home can't be illegal?

This week I've replaced the water level sensor on a washing machine, and the wire feed unit on my small mig. Both were extremely simple non-technical things to do.

I also replaced the pressure switch/unloader on my large 2 phase, hard wired compressor, also a basic job, but bowing to the letter and intent of the law, had a mate (who's a Sparky) check it out before I put the cover back on.

there is a reason why working in the electrical industry is regulated - it's dangerous.

.......2 phase hard wired compressor, ..... never heard of such a beast, guess you mean 3 phase, now work on that DOES require some form of registration, doesn't matter who checked it out later (did your mate provide an electrial safety certificate?).

Fred99

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#1052131 24-May-2014 11:10

gregmcc:

there is a reason why working in the electrical industry is regulated - it's dangerous.

Sure, that's true. There are some common and simple electrical dangers that I suggest are far more likely to result in personal injury or property damage than competent DIY appliance repairs which are allowed under the regulations.
There's a risk with over-regulation - if people are generally so dumbed-down by being continuously told what they're "not allowed" to do, then they won't recognise real dangers when they arise.

Sidestep

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#1052143 24-May-2014 11:23

Fred99:
gregmcc:

there is a reason why working in the electrical industry is regulated - it's dangerous.

Sure, that's true. There are some common and simple electrical dangers that I suggest are far more likely to result in personal injury or property damage than competent DIY appliance repairs which are allowed under the regulations.
There's a risk with over-regulation - if people are generally so dumbed-down by being continuously told what they're "not allowed" to do, then they won't recognise real dangers when they arise.

We don't have 3 phase unfortunately.. it's a 5hp 460V motor just like the ones that ran all the milking sheds out here for years.. so split single phase?
It was complied (back then, by someone from the Electric Power Board) when first installed.

I'll check with my mate, does he have to issue a new cert after maintenance work?
I can see I'll have to catch up on the regs here.

Where we were recently living – overseas – a homeowner could do all their own wiring from the consumer side of the main electrical panel.
So there I wired my own houses..

Edit: clarity

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Sidestep

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#1052147 24-May-2014 11:34

There, the local County gave me a permit with this sage advice..

An owner of a single-family dwelling may do the wiring himself or herself.
We do strongly recommend that Homeowners without a basic knowledge of electric wiring hire a qualified electrical contractor.

gregmcc

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#1052175 24-May-2014 12:27

Sidestep:
Fred99:
gregmcc:

there is a reason why working in the electrical industry is regulated - it's dangerous.

Sure, that's true. There are some common and simple electrical dangers that I suggest are far more likely to result in personal injury or property damage than competent DIY appliance repairs which are allowed under the regulations.
There's a risk with over-regulation - if people are generally so dumbed-down by being continuously told what they're "not allowed" to do, then they won't recognise real dangers when they arise.

We don't have 3 phase unfortunately.. it's a 5hp 460V motor just like the ones that ran all the milking sheds out here for years.. so split single phase?
It was complied (back then, by someone from the Electric Power Board) when first installed.

I'll check with my mate, does he have to issue a new cert after maintenance work?
I can see I'll have to catch up on the regs here.

Where we were recently living – overseas – a homeowner could do all their own wiring from the consumer side of the main electrical panel.
So there I wired my own houses..

Edit: clarity

Any prescribed electrical work requires an ESC, installation work requires a COC as well

Any work outside of ECP50& 51 is perscribed electrical work.

Fred99

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#1052211 24-May-2014 13:27

In theory you can wire up your own house, but not connect it to the switchboard.
In practice it has to be certified by an inspector (not just a regular sparky), so unless the inspector can see exactly what's been done (ie before linings etc were to be put up), then he's very unlikely to want to certify what he can't inspect. It would be wise to discuss this with an inspector prior to starting the work - having to rip all the wiring out and start again from scratch with a sparky doing all the work could be an expensive mistake.

Sidestep

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#1052212 24-May-2014 13:27

gregmcc:

Any prescribed electrical work requires an ESC, installation work requires a COC as well

Any work outside of ECP50& 51 is perscribed electrical work.

OK - just followed gzt's link & read ECP 50.

Thanks appreciate both your postings- that answers my question about what's able to be fixed by the homeowner.

Not much:) - though I see the small grinder's in there..

I'll ask about the ESC.

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