Phased Rotation

[John120/240]

A good lineman can have multiple spans of primary torn down and never reverse rotation on banks without checking with a meter. The lines go back a certain way all over the country.( Or at least on the east side of the Misssissippi where I have worked on storm trouble.)

This example addresses overhead wires on poles

So Hv & Lv what you are saying is; top to bottom: or north to south: or west to east that

there is a utility wide standard for phase ABC to wire position. Interesting.

 

[Hv&Lv]

Yeah, poles are easy, it's the direct burial stuff that's a little harder if not marked.

Actually, the underground is easier. If a pole with the three phase bank is broken by a storm, the underground stays connacted to the pots. If the overhead secondary wires gets ripped off the pole, then the rotation will be 50/50 chance of getting it right.

 

[Hv&Lv]

This example addresses overhead wires on poles

So Hv & Lv what you are saying is; top to bottom: or north to south: or west to east that

there is a utility wide standard for phase ABC to wire position. Interesting.

Not ABC as much as not crossed in the spans. If the rotation is already established and a storm comes in and rips the wires from multiple spans, then they have to be replaced so they do not cross. with a verticle pole, b phase goes to the top, then the other two are installed depending on right or left turn. airlplane analogy is most often used when fixing verticles.

 

[John120/240]

Duh Now the light comes on. Phase rotation was estabilished from the beginning.

You are just replacing wires in these instances.

 

[don_resqcapt19]

Does 408.3(B) enter into this?

 

[kwired]

Does 408.3(B) enter into this?

Did you mean 408.3(E)?

That section states the relationships of phase arrangement in switchboards and panelboards, So once you establish ABC at the service A will always be the left, top,front, etc. but does not address actual rotation.

I'm not completely convinced that all panels need to be the same either, if they are to be the same it is not because of anything in 408.3(E).

 

[broadgage]

The Navy also uses white for an ungrounded conductor identification. White is B phase in three phase ship wiring.

Here in the UK we used to use white for the middle phase of 3 phase supplies.
RED, WHITE, BLUE was the norm up to about 1950, then replaced by RED, YELLOW, BLUE. Neutral being black in both cases.

These days white is not normally used for any line voltage circuit conductors in the UK but is often used within control panels to signify low voltage control circuits.

 

[Hv&Lv]

Here in the UK we used to use white for the middle phase of 3 phase supplies.
RED, WHITE, BLUE was the norm up to about 1950, then replaced by RED, YELLOW, BLUE. Neutral being black in both cases.

These days white is not normally used for any line voltage circuit conductors in the UK but is often used within control panels to signify low voltage control circuits.

for utilities on this side of the pond white is sometimes used for B phase also. Really screws up a lot of electricians, and inspectors.

 

[kwired]

for utilities on this side of the pond white is sometimes used for B phase also. Really screws up a lot of electricians, and inspectors.

And only reason is likely because rotation testers have a white lead on the B phase, right?

 

[John120/240]

And only reason is likely because rotation testers have a white lead on the B phase, right?

That is exactly the reason I have my rotation meter taped yellow on the white lead. .

kwired note Hv&Lv's response

 

[kwired]

kwired note Hv&Lv's response

Sorry for being redundant I was well aware of what he said, I even replied to that post.

 

[Strathead]

As an owner/architect for a department of correction and as an owner/architect for over 35 years, I have never been asked about "phased rotation (PR)" or our requirement/standards during new construction for 'phased rotation'. I have overseen construction of entire new campuses and/or added multi-building additions to existing campuses and never stated a desired standard for PR. Is there a standard of care, as an owner, that all buildings within a new campuses have the same 'PR' or that a new building added to an existing site match the existing buildings? Is there a maintenance standard I need to set-up or address for PR?

Just wondering and need your advice.

Tom

My experience is different than some here. I have worked in CA with PG and E, and Flrida with Progress, SECO, GRU, OEU,Clay Electric. PG and E will allege that whatever you get you get, but I have fought with them more than once to require CW rotation. In a new building with 3 phase motors, I have already done my work and I have no intention of going around and rewiring every disconnect because they are too lazy to verify rotation. Most equipment I have seen is set for CW rotation of the feeders (ABC) from the factory. This is the Southeast, and in most situations, the power supplied is clockwise. I even had a discussion with a Progress Lineman, where he told me how part of their grid in one area was CCW and they take care to reverse two phases on that side of town during new installations. And noted that they had opted not to change it to their standard of CW because of the affect on the customers. So I am not aware of an area where CCW is standard.

 

[jim dungar]

I am typically more concern with the actual phasing rather than just the phase rotation.

CW rotation is often called ABC, but it can also be BCA, and CAB. Connecting paralleled sources using just rotation often results in arcs and sparks.

 

[kwired]

My experience is different than some here. I have worked in CA with PG and E, and Flrida with Progress, SECO, GRU, OEU,Clay Electric. PG and E will allege that whatever you get you get, but I have fought with them more than once to require CW rotation. In a new building with 3 phase motors, I have already done my work and I have no intention of going around and rewiring every disconnect because they are too lazy to verify rotation. Most equipment I have seen is set for CW rotation of the feeders (ABC) from the factory. This is the Southeast, and in most situations, the power supplied is clockwise. I even had a discussion with a Progress Lineman, where he told me how part of their grid in one area was CCW and they take care to reverse two phases on that side of town during new installations. And noted that they had opted not to change it to their standard of CW because of the affect on the customers. So I am not aware of an area where CCW is standard.

If you go south of the equator, is standard rotation CCW?

 

[hillbilly1]

If you go south of the equator, is standard rotation CCW?

The toilets flush that way, why not the electricity! :lol:

 

[Hv&Lv]

And only reason is likely because rotation testers have a white lead on the B phase, right?

Don't know. It was like that long before I began line work. According to some of the older lineman (60+), it has been like that since the 60's.

 

[Hv&Lv]

My experience is different than some here. I have worked in CA with PG and E, and Flrida with Progress, SECO, GRU, OEU,Clay Electric. PG and E will allege that whatever you get you get, but I have fought with them more than once to require CW rotation. In a new building with 3 phase motors, I have already done my work and I have no intention of going around and rewiring every disconnect because they are too lazy to verify rotation. Most equipment I have seen is set for CW rotation of the feeders (ABC) from the factory. This is the Southeast, and in most situations, the power supplied is clockwise. I even had a discussion with a Progress Lineman, where he told me how part of their grid in one area was CCW and they take care to reverse two phases on that side of town during new installations. And noted that they had opted not to change it to their standard of CW because of the affect on the customers. So I am not aware of an area where CCW is standard.

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.

 

[hillbilly1]

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.

It's probably just the order the POCO terminates our end, but I have consistently found Duke Power giving us CCW. What fun is it if you know what the rotation is going to be, you wouldn't be able to do the rotation pools when a building is brought on line. I've wired many a building with multiple motors wired exactly the same, and not all ran the same direction. As you said it's really the luck of the draw, the only piece of equipment that I can guarantee that is connected CW is a new backup generator, but that is because the manufacture ensures this during their testing before they ship it. I don't expect the POCO to deliver it specifically one way or another. Makes it a little difficult hooking a generator after a storm takes out the utility feed, but it is easy enough to check the rotation on a known piece of equipment such as a cardboard baler or indoor fan on a RTU. I did have one though on a grocery store where one of three condenser racks had the fans running backwards. The refrigeration tech that came out later said it had probably been that way since the store opened 20 years ago.

 

[kwired]

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.

That is what I typically run into, 50/50 chance. If everything existing is the same and the supply is incorrect rotation, swap leads somewhere in the supply and move on is what I have always done.

 

[Strathead]

If you go south of the equator, is standard rotation CCW?

I think that depends on which side of the equator the generator is on!:slaphead: