ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
I'll say up front that I don't know much about three phase motors, so please bear with me.
We just finished installing a pretty large PV system on a car dealership with a 480/277V service, and in that process we had to rebuild the service to the facility. Just inside the meter there is a gutter that fed four service discos and now contains our line side interconnection as well. The old gutter was already too small and rusted out, so we replaced it with a new larger one, which meant rebuilding everything inside it. Our electricians paid close attention to what went where and re established all the existing connections exactly as they were.
When the utility came out to inspect our work it was rebuilt and energized, and everything in the facility was running fine, including many three phase motors. The utility informed us that the rotation is reversed and they want us to shut down the service and change it. We are reluctant to do so because it is the same as it was before and everything is running fine as it is.
As I said, I do not know much about three phase motors, but if the three phase supply to a motor is rotation reversed, wouldn't the motor run backwards? We are concerned about liability if we change the service rotation and equipment gets damaged.
We just finished installing a pretty large PV system on a car dealership with a 480/277V service, and in that process we had to rebuild the service to the facility. Just inside the meter there is a gutter that fed four service discos and now contains our line side interconnection as well. The old gutter was already too small and rusted out, so we replaced it with a new larger one, which meant rebuilding everything inside it. Our electricians paid close attention to what went where and re established all the existing connections exactly as they were.
When the utility came out to inspect our work it was rebuilt and energized, and everything in the facility was running fine, including many three phase motors. The utility informed us that the rotation is reversed and they want us to shut down the service and change it. We are reluctant to do so because it is the same as it was before and everything is running fine as it is.
As I said, I do not know much about three phase motors, but if the three phase supply to a motor is rotation reversed, wouldn't the motor run backwards? We are concerned about liability if we change the service rotation and equipment gets damaged.
