phase rotation testers

[shanky887614]

anybody use them.

my jtl training advisor wants me to check phase rotation of motors for portfolio.

i don't see the point. the only motors we use are for fans and vsd driven so you can see what way they spin.

i thought fair enough if there not expensive ill have a look but at £100 ill pass

 

[shanky887614]

What if it's 4 pole ?:laugh3:

wouldnt come across one here mate, 3phase off vsd or built in vsd

 

[davesparks]

I thought poles always came in pairs in motors?

 

[shanky887614]

I thought poles always came in pairs in motors?

nah we have 6 pole motors

 

[davesparks]

Maths not your strong point then shanky?

6 poles is 3 pairs of poles!

 

[Knobhead]

The sensible method is spin the motor before the coupling is fitted.

Get the rotation wrong on some pumps and compressors your going to be changing the unit.

 

[Silly Sausage]

I thought poles always came in pairs in motors?

Have you been hanging around Dover ferry port?

 

[shanky887614]

Same here....more money making unnecessaries, IMO.

yeah jtl have a long list they want you to do.

if i miss anything ive got to do it in the training centre as a last resorts

 

[davesparks]

What is MICV?

 

[ipf]

wouldnt come across one here mate, 3phase off vsd or built in vsd

Hope you don't need any knowledge about them in the future, then.

 

[shanky887614]

What is MICV?

polymeroc sheith oror something acordong to iee

 

[davesparks]

That makes no sense, MICC is mineral insulated copper cable, so how can MICV be anything to do with a polymeric sheath?

 

[Knobhead]

Due to a hangover from the days of us having our own power station all the 11KV boards were BYR. We used 550V on the plants with the same rotation.

Then two new plants were build which were using this weird 433V. Some genius decided the rotation should be RYB. They were separate from the older plants so it didn’t matter.

Then it came to major alterations to one of the old plants. It was to retain 550V for some parts, 433 for the new stuff. Me being the resident idiot got lumbered with the job. First question, which rotation? Because it was overlapping with old stuff we went for BYR.

Again not really a problem as they were separate entities or so we thought. The plants spread out as they tend to and started to overlap. I got saddled with rebuilding a switchroom with 550V BYR, 433V RYB and 433V BYR. I was going dizzy! To add to the confusion the two 433V feeds could be interconnected.

 

[CockneyReject]

Don't envy you mate, borrow a fluke T100 off someone and get the unit/task signed off no point spending coin on something that sounds like will never be used again by yourself

oh and take a little time to brush up on your motor theory too

 

[CockneyReject]

Due to a hangover from the days of us having our own power station all the 11KV boards were BYR. We used 550V on the plants with the same rotation.

Then two new plants were build which were using this weird 433V. Some genius decided the rotation should be RYB. They were separate from the older plants so it didn’t matter.

Then it came to major alterations to one of the old plants. It was to retain 550V for some parts, 433 for the new stuff. Me being the resident idiot got lumbered with the job. First question, which rotation? Because it was overlapping with old stuff we went for BYR.

Again not really a problem as they were separate entities or so we thought. The plants spread out as they tend to and started to overlap. I got saddled with rebuilding a switchroom with 550V BYR, 433V RYB and 433V BYR. I was going dizzy! To add to the confusion the two 433V feeds could be interconnected.

Sounds like fun Tony, any oh **** moments or did it all turn on ok?

 

[shanky887614]

Don't envy you mate, borrow a fluke T100 off someone and get the unit/task signed off no point spending coin on something that sounds like will never be used again by yourself

oh and take a little time to brush up on your motor theory too

yeah i know i need to brush up, havent used some of the knowledge since i got my level3 cert back in 2012.

 

[Knobhead]

Sounds like fun Tony, any oh **** moments or did it all turn on ok?

There's been a few "Why did I do that?" moments.

The best bit was being accused of being drunk. The above switchroom and the great white chief showed up. He noticed incomer 1 was BYR, incomer 2 RYB. Off he goes to the engineering manager saying I must have been drunk to make such a stupid mistake.

At least he had the decency to come back and apologise.




The bottom line, even if the LV intake is reversed so long as the system follows the same rotation throughout you won’t get a problem.

Note, I did say LV, once transformers get involved then there’s phase shift to take in to account. I’ve seen some glorious balls up due to that!

 

[Simon-0116]

Use mine for setting 3 phase sockets up as 123 so all machines working same no matter were plugged in

 

[davesparks]

But you test phase sequence as part of inspection and testing so why do you then need to go round and test with a rotation tester aswell?

 

[shanky887614]

But you test phase sequence as part of inspection and testing so why do you then need to go round and test with a rotation tester aswell?

not all mft's have a phase rotation setting and try getting rotation right on a ct pump when you cant get to fan on pump and no phase tester