Star Delta Problem !

[acestu]

Hi Guys,

My mate has a big fan motor on a star delta starter that used to work fine, the other day it stopped working and when he tries to start it, it starts turning but when it tries to kick into delta it just stops but blows no fuses, he bought a new motor and put it on but it has still got the same problem, does anybody have any ideas before I go to see him because he lives about 300 miles away.

Thanks In Advance
Acestu

 

[Pete999]

Duff starter why waste money on a new motor, when it's more than likely a fault in the starter wiring. You say it starts but blows a fuse, sounds to me and remember I'm not there, that the starter is not switching over to delta at the right time.

 

[telectrix]

pete, he says it stops but doesn't blow any fuses. i'd suspect the changeover or the delta side of the control circuitry long before condemming the motor.

 

[Pete999]

Well perhaps it's the delta contactor failing to take over after the star timer has reached the pre requisite time, could be a delta contactor coil open circuit, or control fuse

 

[Deservices]

Does sound like the delta contactor has died. Shame he didn't get a spark to look first before buying a new motor.

 

[Deservices]

When you say it starts turning. Is it actually getting up to speed?

 

[Bobster]

Sounds like the delta contactors gone duff

 

[Pete999]

Question is why the f--- didn't your mate get someone qualified in before he went and spent good money on something he may not have needed, fishy methinks

 

[acestu]

Question is why the f--- didn't your mate get someone qualified in before he went and spent good money on something he may not have needed, fishy methinks

Hi guys,

You know what people are like, they think they can save money by doing things themselves, well my m8 is no different, I suspect an open coil on the Delta side myself or a dodgy overload, very rare that a timer should change its period they tend to just stop working, thanks for all your suggestions, I wanted to get a few different opinions before I went down, not much left is there after he bought a nice new expensive motor, so he won't want to pay me much then will he LOL !

cheers
Acestu

 

[Knobhead]

What testing has been done? Non by the sound of it.
Does the delta contactor pull in at the transition point?
The motor should be OK as it starts in star but still needs testing.

Are you competent and confident to work on this? I’m sorry if I sound negative, but you can do a lot of damage with Y∆ especially on a fan.

 

[acestu]

What testing has been done? Non by the sound of it.
Does the delta contactor pull in at the transition point?
The motor should be OK as it starts in star but still needs testing.

Are you competent and confident to work on this? I’m sorry if I sound negative, but you can do a lot of damage with Y∆ especially on a fan.

Yes Tony I am qualified and no testing has been done because as I have already stated in the first few lines of my thread the job is about 300 miles away and I haven't been down there yet.

Thanks
Acestu

 

[silva.foxx]

Timer contact not switching fully, star interlock contact not switching, auxiliary block detached, loose wire in control circuit around delta contactor, etc...

 

[Marvo]

If it's 300 miles just take a spare starter or at least a contactor, timer and aux switch blocks with you. Even if he's just paying your travel and mates rates surely it would be cheaper and easier to get someone more local to look at it?

 

[Brightspark2]

300miles?!....

Why not use someone local?...

 

[Darkwood]

All i here is im not competent and my mate wants me to help him .... all of the replies are basic common sense to anyone who is competent to resolve this problem, balls up and tell your mate you don't know its not your field ... the fact he's changed a motor without testing or knowing what the issue was is a red flag to incompetence - we like to help on this forum but we need to express when your out of your depth and should forget it, safety first - pride second!

 

[big-steve]

I did have a similar problem on a fan motor, started in star but when it went into delta it dropped the contractors out. Turns out it was the frost stat relay on the BMS and it started the motor and after 5 seconds interrupted the enable signal and dropped the contractors out, coincidently the star to delta timer was set at 5 seconds.