Phase rotation advice

[Phil]

Hello all,
I'm after some advice on my current situation as I've never came across this before and trying to find answers online are not producing any results.

Basically I've got a 3 Phase motor, checked voltages across the 3 lines and neutral, everything is as it should be.

Checked rotation, L1 to L2 ok, L2 to L3 is not showing rotation but it's showing 400V, L3 to L1 is ok.

Why would L2 to L3 not show rotation but will show 400V?

Thank you for any advice.

 

[Pete999]

Hello all,
I'm after some advice on my current situation as I've never came across this before and trying to find answers online are not producing any results.

Basically I've got a 3 Phase motor, checked voltages across the 3 lines and neutral, everything is as it should be.

Checked rotation, L1 to L2 ok, L2 to L3 is not showing rotation but it's showing 400V, L3 to L1 is ok.

Why would L2 to L3 not show rotation but will show 400V?

Thank you for any advice.

What test equipment are you using?

 

[Phil]

Just to add to my original post, I've load tested the genset with a 3 Phase heater whilst out on site, again everything was at it should.

The reason for the questions is because someone has hired one of our generators for a hoist, last night the generator was shutting down for reverse power. I've came to site, checked everything over with the generator, checked the wiring up to the hoist and now waiting for their hoist engineer to turn up.

Edit: just seen your reply. It's a ethos 4164 phase rotation tester.

 

[telectrix]

don't quite understand your question. to check rotation, you connect all 3 lines to the rotation meter. then it shows the direction of the phase rotation, clockwise or anti-clockwise.

 

[Pete999]

Hello all,
I'm after some advice on my current situation as I've never came across this before and trying to find answers online are not producing any results.

Basically I've got a 3 Phase motor, checked voltages across the 3 lines and neutral, everything is as it should be.

Checked rotation, L1 to L2 ok, L2 to L3 is not showing rotation but it's showing 400V, L3 to L1 is ok.

Why would L2 to L3 not show rotation but will show 400V?

Thank you for any advice.

Why would you have TP& N at the three phase motor? I take it the motor is a bog standard Squirrel cage type machine, nothing special about it?

 

[Phil]

don't quite understand your question. to check rotation, you connect all 3 lines to the rotation meter. then it shows the direction of the phase rotation, clockwise or anti-clockwise.

Sorry, it probably the way I worded my post.

I know how to check phase rotation but when I check between L2 and L3 no indication is shown for the direction of rotation, yet 400V is shown. When I check between L1 and L2, correct rotation is shown and between L3 and L1 correct rotation is shown.

Yes Pete, it's a squirrel cage type machine.

 

[westward10]

Why would you have TP& N at the three phase motor? I take it the motor is a bog standard Squirrel cage type machine, nothing special about it?

Tell Michael Faraday that

 

[telectrix]

clear now, having watched the video that pete posted. i've never checked rotation using his 2nd method.

 

[telectrix]

Tell Michael Faraday that

get more sense telling michael flatley.

 

[Pete999]

Tell Michael Faraday that

???????

 

[westward10]

???????

Was having a jest Pete where you said "nothing special about it"

 

[Pete999]

Was having a jest Pete where you said "nothing special about it"

Thought you were, I'm a bit touchy this morning, bad night.

 

[Phil]

I don't know if this link will work from Google photos.
https://goo.gl/photos/NVQmta5qwXiutE3w7

Sorry about the quality, trying to record on the phone with one hand and test with the other.

To add to the confusion, when I load tested the generator, all three phases displayed correct rotation.

 

[telectrix]

you OK Pete?

 

[Pete999]

you OK Pete?

No Tel had a bad night, been up since about 2 this morning, thanks for asking.