Is testing necessary to identify an open delta electric service?
Without doing voltage testing, is it possible to visually identify that an electric service is open delta`?
Comments
Beebe77,
On the load side, an open Delta service may look just like a 3-phase, 3 transformer service. Open Delta is an inefficient way to make 3-phase power available from 2 transformers.
I'm not sure what kind of test you could do on the load side to determine that it's open delta. Best bet would be to just contact the local utility and ask them.
Some people who know transformers really well can look up at a power pole or into a vault and identify an open delta service - otherwise, I would say that the answer to your question is "no" when inspecting the service right at the meter.
Yes, ideally you would select a three phase inverter for the application. However, one option is to go with two 240V inverters of equal size that are connected across any two phases. The other is to go with three 240V inverters connected on each phase, each of the same size. As long as the inverters can be installed without connecting to a neutral you should be ok (Fronius comes to mind, however there are likely others too).
Be sure you consult with the utility to find out how much, if any, phase imbalance they will permit for interconnected PV systems.
Comments
Beebe77,
On the load side, an open Delta service may look just like a 3-phase, 3 transformer service. Open Delta is an inefficient way to make 3-phase power available from 2 transformers.
I'm not sure what kind of test you could do on the load side to determine that it's open delta. Best bet would be to just contact the local utility and ask them.
Some people who know transformers really well can look up at a power pole or into a vault and identify an open delta service - otherwise, I would say that the answer to your question is "no" when inspecting the service right at the meter.
What is the appropriate solar inverter to be used in open delta system? Three phase inverter or 2 nos. of single phase inverter?
Yes, ideally you would select a three phase inverter for the application. However, one option is to go with two 240V inverters of equal size that are connected across any two phases. The other is to go with three 240V inverters connected on each phase, each of the same size. As long as the inverters can be installed without connecting to a neutral you should be ok (Fronius comes to mind, however there are likely others too).
Be sure you consult with the utility to find out how much, if any, phase imbalance they will permit for interconnected PV systems.