Starters and motors

i=p/u · Feb 5, 2015

was looking at a motor the other day and when I measured across all I got was 230v to Earth but not 400v between.

i=p/u · Feb 5, 2015

Rating ate.

i=p/u · Feb 5, 2015

What's this?

davesparks · Feb 5, 2015

i=p/u said:
View attachment 27775What's this?

A PCB with some wires connected to it.

Pete999 · Feb 5, 2015

i=p/u said:
was looking at a motor the other day and when I measured across all I got was 230v to Earth but not 400v between.

Across what and between what?

Darkwood · Feb 5, 2015

What controls the motor? .... DOL, VSD, Star/Delta, Soft Start etc etc?
Has it got speed control?
What meter are you using to get your voltage?
What's the nature of this post... is something wrong with the motor or its operation?

D Skelton · Feb 5, 2015

The links are arranged in star formation. If you measure between each incoming phase to the star point of course you're only going to get 230V. That is of course assuming direct connection to the supply. What voltage are you getting between the incoming phase terminals? How is the motor started?

ipf · Feb 5, 2015

i=p/u said:
View attachment 27774Rating ate.

Did it taste good?

i=p/u · Feb 5, 2015

Ate screws and all.. Ipf

i=p/u · Feb 5, 2015

darkwood said:
What controls the motor? .... DOL, VSD, Star/Delta, Soft Start etc etc?
Has it got speed control?
What meter are you using to get your voltage?
What's the nature of this post... is something wrong with the motor or its operation?

I know nothing about controls and motors. I measured 400v at isolator , which then goes to id say is a starter of some sort (pic). I then measured 230v at motor housing. I used martingale gs38 tester

VoltzElectrical · Feb 5, 2015

i=p/u said:
I know nothing about controls and motors.

Neither do I, that's why I leave it to others!

davesparks · Feb 5, 2015

i=p/u said:
I know nothing about controls and motors.

Then leave it alone and advise your client to hire someone who does

baldsparkies · Feb 5, 2015

i=p/u said:
I know nothing about controls and motors.

Sorry, but having said that !!
What exactly are you trying to achieve here ??
I think you should put that cover back on to be honest and get someone with you who does know about motors and control gear.

i=p/u · Feb 5, 2015

Guys and divas , I only check power at devices after that the boss sends it back for specialist which I asumme in this case is an electrical engineer .

i=p/u · Feb 5, 2015

Haven't even told you about the caretaker and your telling me to put cover on lol.

i=p/u · Feb 5, 2015

VoltzElectrical said:
Neither do I, that's why I leave it to others!

Agree totally

Marvo · Feb 5, 2015

If it's supplied by a variable frequency drive there's a good chance your tester won't be able to make sense of the supply at the motor due to the high carrier/switching frequencies.

i=p/u · Feb 5, 2015

Is that not a drive in the pic Marvi

Marvo · Feb 5, 2015

I wasn't entirely sure what that was in the pic. Have you got another pic taken from a bit further away?

i=p/u · Feb 5, 2015

Marvo said:
If it's supplied by a variable frequency drive there's a good chance your tester won't be able to make sense of the supply at the motor due to the high carrier/switching frequencies.

I measured 230v at all points on motor to earth but nothing between connections

Marvo · Feb 5, 2015

Was the motor running?

davesparks · Feb 5, 2015

i=p/u said:
Guys and divas , I only check power at devices after that the boss sends it back for specialist which I asumme in this case is an electrical engineer .

If you don't understand the basics of motor control then how do you know what you are testing for or what test equipment is appropriate/safe to use?

i=p/u · Feb 5, 2015

Dave not my job now so fuk it . Just a little interested .

elevate · Feb 5, 2015

Its not a drive in the picture, the circuit board looks like some sort of RC circuit, could be for soft start or noise suppression. Any wiring diagrams?

i=p/u · Feb 5, 2015

And out of interest its a band saw. With two emergency stops onit plus start stop button

Marvo · Feb 5, 2015

It's not a drive and it's a bit elaborate for a suppression board plus there's no ground on it. Maybe soft start but I can only see 2x components on the heat sink so also unlikely.

You didn't say if the motor was running or not. What was the fault they reported and what was the application or machine it was a part of?

Silly Sausage · Feb 5, 2015

i=p/u said:
View attachment 27778 Dave not my job now so fuk it . Just a little interested .

Who pulled all the inards out?

Marvo · Feb 5, 2015

My tying is too slow, it's probably the control board for the interlocks / estop etc. In that case the motor looks like it's direct on line so I give up about your weird test results in that case.

i=p/u · Feb 5, 2015

The fault was bandsaw not working. It also has a dust extractor tapped off it

i=p/u · Feb 5, 2015

But as said why only getting 230v motor connections,

why nit not just break live with e stops , forget control boards ...

Silly Sausage · Feb 5, 2015

i=p/u said:
The fault was bandsaw not working. It also has a dust extractor tapped off it

1: Determine make and model of said saw.
2: Ask Maintenance if they've got a manual for it.
if not,
3: Get online and see if you can find one.
if not .......

Marvo · Feb 5, 2015

The only explanation of getting 230v from all terminals to earth and 0 v between the terminals themselves is that there's only asingle phase being supplied to the motor. That's the easy bit, the difficult bit is figuring what's causing that condition. Maybe the contactor was not energised but one of the contacts is welded closed due to a fault current that occurred previously but then the question becomes what was the earth or the s/c fault.

netblindpaul · Feb 5, 2015

That's a Klinger & Born DOL starter with O/L & d.c. injection brake.

ipf · Feb 5, 2015

Marvo said:
The only explanation of getting 230v from all terminals to earth and 0 v between the terminals themselves is that there's only asingle phase being supplied to the motor. That's the easy bit, the difficult bit is figuring what's causing that condition. Maybe the contactor was not energised but one of the contacts is welded closed due to a fault current that occurred previously but then the question becomes what was the earth or the s/c fault.

Just going to ask if he'd checked the fuses:icon12:

i=p/u · Feb 5, 2015

Tell me more netball

Marvo · Feb 5, 2015

Thanks Paul, I was hoping someone would recognise it.

netblindpaul · Feb 5, 2015

It's what I do for a living remember, not recognising, but machinery stuff, from fixing, to designing, to consulting on CE & PUWER in the main.

i=p/u · Feb 5, 2015

Which fuses Ipf ? On the circuit board? Yes there's one which Belleyed out.

theres 400v at dol starter but only 230v at motor casing.

when you hit the start button , the extractor kicks in, the pulls out again and there's a burrRRrr sound but blade don't rotate.

and believe me when I say I ain't fixing this . But would love too some day lol

ipf · Feb 5, 2015

i=p/u said:
Which fuses Ipf ? On the circuit board? Yes there's one which Belleyed out.

theres 400v at sol starter but on 230v at motor casing

Fair do's.....but we're all guessing a bit at fault finding without being on the spot.

i=p/u · Feb 5, 2015

So why pcb board netball? What we got here

-

Attachments

-

-

davesparks

-

Darkwood

-

-

-

-

-

davesparks

baldsparkies

-

-

-

-

-

-

-

-

davesparks

-

-

-

-

Silly Sausage

-

-

-

Silly Sausage

-

-

-

-

-

-

-

-

-

Similar threads

OFFICIAL SPONSORS

Advert

Daily, weekly or monthly email

Thread starter

Thread Information

Thread Tags

Advert

Thread statistics

Advert