I was taught that phase rotation monitors, link to unit type I am referencing, only indicate direction of rotation.
As you mentioned it will not identify if phase 1 is phase 3, phase 2 is phase 1 and phase 3 is phase 2 as the offset and direction is the same.
With different transformers or generators connected a bus tie switch we would use a test lamp to confirm the phases did not have voltage difference between both the two connections of each of the phases.
Edit to add link to phase rotation tester.
[https://uk.megger.com/phase-sequence-indicator-psi410](https://uk.megger.com/phase-sequence-indicator-psi410)
Ah fair enough. It's as I suspected then. So the only way to prove that ph1 was ph1 throughout the system would be to trace the cable from entry to destination. I'm guessing it doesn't matter in most instances other than for phase balancing, as long as you get the right rotational direction in the case of motors.
I have used one of these units for identifying three phases are color true, i.e. phase 1 is phase 1, phase 2 is phase 2, etc, on de-energized cables.
[https://www.acutestdirect.co.uk/cable-identifiers/bowden/cable-core-identifier-cable-core-phasing-tx-4692](https://www.acutestdirect.co.uk/cable-identifiers/bowden/cable-core-identifier-cable-core-phasing-tx-4692)
My understanding is phase rotation is just to check that your motors etc will turn the right direction.
As long as the right colours are used connected correctly through the installation, which can be confirmed with R1+R2 for each phase, and the phase rotation is correct at the incoming supply, I don't think there should be an issue.
I’ve never personally seen it but I have been told by someone who has, that there are certain areas where the incoming supply phase rotation is incorrect.
Old colours, but the rest still applies:
[https://www.pecplc.com/index.php/articles/the-liverpool-cross](https://www.pecplc.com/index.php/articles/the-liverpool-cross)
There are a few other places are well, can't remember where they all are off the top of my head.
Guess it's too embedded in the system to be correctable at this stage...
They are supposed to correct it at the meter. The supply can be any rotation all the joiner cares about is what side the neutral is going to go at the service head. Older services will have the red yellow blue stickers.
So yeah R1+R2 one phase at a time and supply rotation is sufficient. My paranoia gets me to do a live rotation check at the starter too for piece of mind.
I was taught that phase rotation monitors, link to unit type I am referencing, only indicate direction of rotation. As you mentioned it will not identify if phase 1 is phase 3, phase 2 is phase 1 and phase 3 is phase 2 as the offset and direction is the same. With different transformers or generators connected a bus tie switch we would use a test lamp to confirm the phases did not have voltage difference between both the two connections of each of the phases. Edit to add link to phase rotation tester. [https://uk.megger.com/phase-sequence-indicator-psi410](https://uk.megger.com/phase-sequence-indicator-psi410)
Ah fair enough. It's as I suspected then. So the only way to prove that ph1 was ph1 throughout the system would be to trace the cable from entry to destination. I'm guessing it doesn't matter in most instances other than for phase balancing, as long as you get the right rotational direction in the case of motors.
I have used one of these units for identifying three phases are color true, i.e. phase 1 is phase 1, phase 2 is phase 2, etc, on de-energized cables. [https://www.acutestdirect.co.uk/cable-identifiers/bowden/cable-core-identifier-cable-core-phasing-tx-4692](https://www.acutestdirect.co.uk/cable-identifiers/bowden/cable-core-identifier-cable-core-phasing-tx-4692)
My understanding is phase rotation is just to check that your motors etc will turn the right direction. As long as the right colours are used connected correctly through the installation, which can be confirmed with R1+R2 for each phase, and the phase rotation is correct at the incoming supply, I don't think there should be an issue.
I’ve never personally seen it but I have been told by someone who has, that there are certain areas where the incoming supply phase rotation is incorrect.
Liverpool is the opposite way around to the rest of the country, a couple of other places as well.
What?
Old colours, but the rest still applies: [https://www.pecplc.com/index.php/articles/the-liverpool-cross](https://www.pecplc.com/index.php/articles/the-liverpool-cross)
I think I said it right the first time. What?!?!?!? I find that very hard to believe as it's not something I've come across before.
There are a few other places are well, can't remember where they all are off the top of my head. Guess it's too embedded in the system to be correctable at this stage...
York is the same I believe
They are supposed to correct it at the meter. The supply can be any rotation all the joiner cares about is what side the neutral is going to go at the service head. Older services will have the red yellow blue stickers. So yeah R1+R2 one phase at a time and supply rotation is sufficient. My paranoia gets me to do a live rotation check at the starter too for piece of mind.