Shadetree
New member
- Location
- Atlanta, Ga.
Hi all,
First, I'm not an electrician, but rather an electronics technician, so please pardon my lack of familiarity here. (I do know my basic electrical safety - have been repairing electrical equipment for many years.) Second, I'm not looking for DIY advice / to avoid hiring a licensed electrician - I just want to know what's going on before I do that. OK so here goes - hope this is suitable for the forum.
I need to run a three phase load (motor), and coincidentally, it appears that I may have three phase service already. My questions are 1) how to identify what I have, and 2) whether that is suitable for this load. There are no other unusual / three phase loads besides this.
There are three panels/boxes; everything looks old to me. One is the main disconnect - what I would call a blade-style cut-off switch - three poles & 150A fuses. Second is the breaker panel. Third is a much smaller cut-off, also with fuses, which serves only the HVAC.
The main cut-off has four wires entering from the street, one grounded. (I assume this is a neutral?) (Picture attached). The three remaining are not marked, so far as I can tell. >> All of these are 240v from any one to any other.
>> The line to neutral voltages are 120, 120, and 208(?), working in order from from left to right.
>> The currents in these three legs are 14A, 8A, and 0A, again working from left to right.
(voltages are nominal - actual measurements are all higher for some reason, esp. the 208. I can list if needed)
So again, I hope to verify that this is/is not three phase power, and if so, which phase is which. I know from working on other things in the past that phases have to be connected to motors in the right order. I figure I'll end up with somebody that does residential work, and worry that he may not remember this detail ... ? It would be nice to have them marked.
Thanks - any help appreciated.
First, I'm not an electrician, but rather an electronics technician, so please pardon my lack of familiarity here. (I do know my basic electrical safety - have been repairing electrical equipment for many years.) Second, I'm not looking for DIY advice / to avoid hiring a licensed electrician - I just want to know what's going on before I do that. OK so here goes - hope this is suitable for the forum.
I need to run a three phase load (motor), and coincidentally, it appears that I may have three phase service already. My questions are 1) how to identify what I have, and 2) whether that is suitable for this load. There are no other unusual / three phase loads besides this.
There are three panels/boxes; everything looks old to me. One is the main disconnect - what I would call a blade-style cut-off switch - three poles & 150A fuses. Second is the breaker panel. Third is a much smaller cut-off, also with fuses, which serves only the HVAC.
The main cut-off has four wires entering from the street, one grounded. (I assume this is a neutral?) (Picture attached). The three remaining are not marked, so far as I can tell. >> All of these are 240v from any one to any other.
>> The line to neutral voltages are 120, 120, and 208(?), working in order from from left to right.
>> The currents in these three legs are 14A, 8A, and 0A, again working from left to right.
(voltages are nominal - actual measurements are all higher for some reason, esp. the 208. I can list if needed)
So again, I hope to verify that this is/is not three phase power, and if so, which phase is which. I know from working on other things in the past that phases have to be connected to motors in the right order. I figure I'll end up with somebody that does residential work, and worry that he may not remember this detail ... ? It would be nice to have them marked.
Thanks - any help appreciated.
