Stupid Brook Crompton Name plates 1

[Feg]

Hi All,

I have just done a shift where we had to go in a fit a new motor to replace a new brook crompton motor which only lasted 1 day. The original Brook motor worked for 2 years it was a 45Kw 4pl marked 400v and the name plate did not say star or delta it is totally black inside and was very hot at some stage, it was replaced again with a new Brook Crompton 45Kw 4pl marked 400V Delta and it failed in 1 day.

The fitter that changed out motor 2 in his wisdom re-connected the new motor marked 400V delta in star because the original work this way, I know "read the name plate". My question is as follows: the original motor did not indicate star or delta but my thinking is lower voltage always delta but the motor ran for 2 years in star, does Brook mke this motor in 400V star. Can anyone shed some light on this as the Brook office are of no help.

 

[ScottyUK]

Stop blaming the nameplate! The installer is responsible for matching the motor to the supply.

Why did the thermal overload protection not operate? Is it set correctly? Is it fitted? Does it work?

On a machine of that size I would expect it to be a 400V delta / 690V star machine but it is your responsibility to verify that before connecting it. If it is a 400/690 machine then running it in star on a 400V supply will cause it to run at abnormally high slip if it runs at all. This will cause the rotor to get very hot leading to failure.

Either post a decent photo of the nameplate (check the FAQ's for details of how to do this) or post ALL the information on the nameplate and maybe we could help. I am surprised at the problems with Brooks, although if your phone call had the same attitude as the title of this thread maybe I shouldn't be. Stay professional, however pissed off you are.



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Sometimes I wake up Grumpy.
Other times I just let her sleep!

 

[Feg]

The Motors are powered by VSD, and the overloads are set correctly, I am of the opinion that the motors are far too big for this application.

ScottyUK, I agree the person connecting it is responsible, I do not have an image of the name plate but the name plate is very poor in that the original motor only says 400V no delta or star symbol. I am also surprised, surprised that you think Brook would be any help because for many years now the service has been quite poor.

 

[ozmosis]

If your motor has gone up in smoke and the VSD has not protected it, then I would seriously look at the settings made in the VSD. Most VSD's today will have a level of protection to prevent a motor going up in smoke.
However, I just read your post again and you mention "motors". Do you have more than one motor per VSD? If so, then individual thermal overloads per motor are a must and these should have kicked out before smoke billows.

Regarding Brooks. It appears they have gone downhill since the demise of their factories in the UK but I would not bother going to them direct but try one of their distributors, you often get better service:

http://www.brookcrompton.com/pages/service.asp

 

[Feg]

No there is just 1 motor per VSD, but 2 motors have failed 1 lasted approx 2 years the new replacement just 1 day. I am mechanical and my job was to change the motor out which I did after the 2nd Brook failed, I fitted a Siemens multi voltage motor wound 400/690 Delta/Star it seams to be working fine but is only installed a few days. I am just a little concerned that this motor will give a problem as I fitted this. I would have thought that the Brook motors if they were wired wrong would have caused the vsd to go out on high current.

 

[jraef]

All motor manufacturers make different versions of their products for use in different parts of the world to accommodate the various power distribution systems. Sometimes when you order something and they are out of one type, they may substitute one of a equivalent functional design that will work. In your case, if you ordered a 45kW 400V motor, that's what you got. Had you ordered a 45kW 230/400V motor, you would have propabably received one exactly like others you are more familiar with. There is no requirement for a motor to use one type of internal connection or another if only one voltage is specified. It pays to be specific.

If the motor didn't have a Star or Delta symbol on it, that was probably not being "stupid" as you put it, it very likely meant that it was only intended for one voltage connection, i.e. it was a 400/690V winding pattern, but the connections were not rated for 690V, so they had to omit the 690V rating from the nameplate. That being the case, the internal connection diagram would only have needed to show the one valid connection pattern, in that case Delta. Your electrician took it upon himself to ignore the obvious and ASSume that the manufacturer was wrong!

Most likely, if the old motor was not marked as dual voltage either and you were running it for 2 years in Star (the 690V pattern), the equivalent kW rating would have been 58% of nameplate or 26kW. If, as you said, the motor was grossly over sized to begin with, this may have gone completely unnoticed for a long time. Only if the load demanded more than 26kW would the motor have gone in to overload and tripped the OL function the VFD. As others have said, I would triple check the OL function programming on that VFD.

 

[ScottyUK]

Feg,

I agree about the quality of Brook motors - since manufacture moved to Poland (bad) and China (worse) the quality has definitely dropped. There are still some knowledgeable people in the Brook distribution chain who are usually pretty good.

If you are correct and the motors are grossly oversized then running them incorrectly wired for 690V may not have harmed them simply because they are running at such light load that the slip has remained low enough not to trouble the rotor. On the burned up motor could you identify whether the heat originated in the rotor or stator?

Slight aside for sed2: I heard a rumour that Siemens were shifting motor production to an Eastern Bloc country. Is this true? Hopefully the fate of Brooks does not await Siemens. We have been pleased with the Siemens machines up until now; we used to say that about Brook machines too.


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Sometimes I wake up Grumpy.
Other times I just let her sleep!

 

[ozmosis]

Scotty
I wouldn't say 'shifting'. They've had motor production in the Czech Republic for about 8~9 years now. Still have manf in Germany (Bad Neustadt) though, and quite a number are still coming out of there. There's production in Mexico (NEMA), India and China and one or two others but the latter are for home supply rather than export, in the main. As the large proportion of the cost of a motor is transportation, it makes little sense to ship them from half way round the world.

 

[ScottyUK]

Thanks - sounds like our source is either way behind the times or is spreading rumour and not fact.

 

[itsmoked]

I was called to a hydraulic press\shear that was 5hp. They were complaining that the operator had to manually modulate the 'lever' or the motor would stall. They were having throughput problems since production demands had crept up over the last year. They demonstrated this to me and if the pressure exceeded about 2000psi the motor would indeed stall. They needed 2600psi to be happy. The motor was being run with a phase converter from 240VAC. They assumed it was a problem with the phase converter. After examination it was found that they'd wired the motor for 460VAC yet had been running it that way for over a year. We switched the connections and the system started and hit 8,000psi since they'd screwed the pressure relief valve all the way down.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[jraef]

Heh... got that T-shirt and the hat...

I once hooked up a 350HP rock crusher to the wrong winding pattern (Weg motor, designed for 440Y760V, long story, won't bore you all with it). Ran absolutely fine in the shop, shipped it across the country, ran fine when run unloaded for the demo to the user. Everyone signed off on it, the bills were paid, the salesmen got their commission checks etc. etc.

Until someone dropped the first rock into it...

 

[Feg]

ScottyUk,

I used Brook for years with no problems but now the quality seams poor, ABB and Siemens are the only companies of late that keep the quality good. As stated above SIEMENS have been making motors in the Czech Rep for a long time but only for part of there small range of motors and they are very good.

The windings are black as coal and the rotor looks fairly good so most of the heats seams to have been in the windings. Since my original post I have found out the motor is only drawing 32 amps.