Phased Rotation

[Strathead]

Don't know who you are fighting with, but there isn't a standard rotation for utilities. Rotation can be screwed up from the high line on. Normally, if an electrician has done the work on his motors to try and ensure rotation, I will try to accomodate him/her. That is, unless the attitude is showing. Then it is "you get what we deliver".

We are not responsible for rotation for new services, period. We are in the southeast, there is a 50/50 chance it will be right.

Specifically P G and E in Ca. I had more than one job with numerous pieces of 3 phase equipment. I would clearly state on my request to for hook up that I wanted CW rotation. Once the crew gave me a hard time, but after a little persuasion they changed it. the other time the crew refused. I got on the phone and talked to supervision until I got satifaction. IMO, it is very reasonable, and far easier to check the rotation at the service than to go around to 50 disconnects and change every one. It is not racket science and there really should be a standard set by the Utility.

 

[kwired]

Specifically P G and E in Ca. I had more than one job with numerous pieces of 3 phase equipment. I would clearly state on my request to for hook up that I wanted CW rotation. Once the crew gave me a hard time, but after a little persuasion they changed it. the other time the crew refused. I got on the phone and talked to supervision until I got satifaction. IMO, it is very reasonable, and far easier to check the rotation at the service than to go around to 50 disconnects and change every one. It is not racket science and there really should be a standard set by the Utility.

I suppose if we are talking service conductors that are composed of multiple parallel conductors, then it is a big job just to change rotation at the service conductors. It is likely easier task for POCO to swap primary leads. For smaller services, especially where there is no paralleled conductors, it is not a big deal.

 

[Hv&Lv]

Specifically P G and E in Ca. I had more than one job with numerous pieces of 3 phase equipment. I would clearly state on my request to for hook up that I wanted CW rotation. Once the crew gave me a hard time, but after a little persuasion they changed it. the other time the crew refused. I got on the phone and talked to supervision until I got satifaction. IMO, it is very reasonable, and far easier to check the rotation at the service than to go around to 50 disconnects and change every one. It is not racket science and there really should be a standard set by the Utility.

I agree that is a reasonable request. My request would be that you were there during connection with your rotation meter doing the checking.

That is, unless it was multiple runs of parallell.

 

[Strathead]

I suppose if we are talking service conductors that are composed of multiple parallel conductors, then it is a big job just to change rotation at the service conductors. It is likely easier task for POCO to swap primary leads. For smaller services, especially where there is no paralleled conductors, it is not a big deal.

And it is even easier for them to take the three minutes to do a phase rotation test before even hooking up the wires. That is my point. To me, there is no more an excuse for them not providing uniform rotation to their customers than there is in my guys doing hlf baked work like say, not lining up their cover plate screws.

 

[Hv&Lv]

It is likely easier task for POCO to swap primary leads. .

No it isn't, without compromising uniformity. It should never be done on an overhead bank for reasons of safety, and doesn't need to be done in a padmount.

 

[Hv&Lv]

And it is even easier for them to take the three minutes to do a phase rotation test before even hooking up the wires. That is my point. To me, there is no more an excuse for them not providing uniform rotation to their customers than there is in my guys doing hlf baked work like say, not lining up their cover plate screws.

I have went through the procedures you mention to please electricians before. I have never had one get every motor turning the right way the first time.

I had one ask me to switch the wires because he had a motor turning backwards and they were all wired the same way. This was a new asphalt plant being put online. I switched the wires, and his motor was turning the right way, so I packed up and left.

I wasn't gone from the sight more than 20 minutes when the dispatcher radioed and said the electrician called and requested the wires be switched.
The electrician failed to tell the dispatcher that we had switched them once for him. I called in and told the engineering department what happened, and I really didn't want to go back and switch the wires again, but it was the head engineers call.

The engineer called the electrician and told him we switched them once for him, the second time was on him. If he would pay us to switch them again, we would be more than happy to.
Apparently, all the motors weren't wired the same way...

 

[Strathead]

I agree that is a reasonable request. My request would be that you were there during connection with your rotation meter doing the checking.

That is, unless it was multiple runs of parallell.

And I always was. Now I don't work any more, I just push a pencil.

 

[Strathead]

I have went through the procedures you mention to please electricians before. I have never had one get every motor turning the right way the first time.

I had one ask me to switch the wires because he had a motor turning backwards and they were all wired the same way. This was a new asphalt plant being put online. I switched the wires, and his motor was turning the right way, so I packed up and left.

I wasn't gone from the sight more than 20 minutes when the dispatcher radioed and said the electrician called and requested the wires be switched.
The electrician failed to tell the dispatcher that we had switched them once for him. I called in and told the engineering department what happened, and I really didn't want to go back and switch the wires again, but it was the head engineers call.

The engineer called the electrician and told him we switched them once for him, the second time was on him. If he would pay us to switch them again, we would be more than happy to.
Apparently, all the motors weren't wired the same way...

I think I am smarter than that. I always wanted CW rotation period. If a motor ran backward then I would switch it or all of them if I was provided CW rotation. For the record I am Anal!

 

[Hv&Lv]

I think I am smarter than that. I always wanted CW rotation period. If a motor ran backward then I would switch it or all of them if I was provided CW rotation. For the record I am Anal!

Can't say much about that, I have been called anal myself...

I noticed that when you stated the screws lining up on cover plates. I do that also on ther ones I install or repair.

 

[boboelectric]

These new scroll compressors and a/c units are really
rotation sensitive .

 

[kwired]

These new scroll compressors and a/c units are really
rotation sensitive .

All the more reason to have phase monitors in the controls. If input is wrong rotation for any reason the controls lock it out.

 

[hillbilly1]

All the more reason to have phase monitors in the controls. If input is wrong rotation for any reason the controls lock it out.

We lucked out on a store that had scroll compressors, the manufacture had every RTU with built in phase loss and phase reversal in the units. One of our guys hooked up a generator to power the store while the utility was down due to a hurricane. The power was restored, so I was sent to disconnect the store from the generator and put it back on utility. When I arrived there, the manager was glad to see me, he said the bailer and compactor didn't work, and he had a receiving area full of trash. That sent a red flag up for me, because both should have worked on generator. Sure enough, our guy had the rotation wrong. Luckily nothing was damaged. It would have been very expensive to replace every compressor on that roof.