In 1993 I installed an underground feed 800 amp three phase 4 wire 120/240 volt open delta service feeding a 10,000 sq. ft. commercial building.
Our utility installed pole mount transformers with wires coming down the pole to an underground splice box at the base of the pole. From this splice box I was required to install two 4" (PVC) conduits to feed the 800 amp main. The main has a Utility pull section, a section containing a meter with a 400 amp 3 phase main feeding (1) 200 amp 3 phase breaker and (1) 125 amp single phase breaker, and a section with (4) 200 amp 3 phase meters feeding breakers and panels within the building. This was the installation in 1993.
14 years later I am informed that the Utility conductors to the building are 350 MCM AL and are over heating due to load.
The Utility informs me that an 800 amp service does not mean that they provide the conductors for an 800 amp service.
I've talked to two electrical engineers, one says they should have pulled the correct conductors at first installation, the second says I should have known what wires they installed and it's original limitations.
I have a couple of questions...
(1) Is this common practice?
(2) The Utility informs me that they do not do 800 amp pole mount transformers and I will have to re-trench through a concrete parking lot to supply a pad mount transformer. Shouldn't this have been their engineering spec from day one?
(3) Who should pay for all this?
Thanks,
gs
Our utility installed pole mount transformers with wires coming down the pole to an underground splice box at the base of the pole. From this splice box I was required to install two 4" (PVC) conduits to feed the 800 amp main. The main has a Utility pull section, a section containing a meter with a 400 amp 3 phase main feeding (1) 200 amp 3 phase breaker and (1) 125 amp single phase breaker, and a section with (4) 200 amp 3 phase meters feeding breakers and panels within the building. This was the installation in 1993.
14 years later I am informed that the Utility conductors to the building are 350 MCM AL and are over heating due to load.
The Utility informs me that an 800 amp service does not mean that they provide the conductors for an 800 amp service.
I've talked to two electrical engineers, one says they should have pulled the correct conductors at first installation, the second says I should have known what wires they installed and it's original limitations.
I have a couple of questions...
(1) Is this common practice?
(2) The Utility informs me that they do not do 800 amp pole mount transformers and I will have to re-trench through a concrete parking lot to supply a pad mount transformer. Shouldn't this have been their engineering spec from day one?
(3) Who should pay for all this?
Thanks,
gs