Here?s and odd one, our service voltage is 4160 and the local Utility plans to increase the voltage to 12470. Our service equipment, while rated at 15k, will not handle the increased voltage based on age and engineering judgment.
The Utility?s solution is to install a step-down transformer.
Our long range plan is to reduce our service voltage to 480, so the Utility is providing a 12470 to 480 volt transformer on their end and providing a temporary step-up transformer from 480 to 4160 at our service. The conduit, wire between the transformers and metering enclosures will be installed and owned by us.
Is the temporary transformer and wire Utility equipment or customer equipment during this temporary period of 2 to 5 years?
The Utility feels that the primary fusing on the 12470 and 4160 is sufficient to protect their system. Our engineer is concerned about our liability if we do not provide over current protection for the step up transformer.
Is there a specific NEC reference requiring over current protection for the step-up transformer in this scenario?
The Utility?s solution is to install a step-down transformer.
Our long range plan is to reduce our service voltage to 480, so the Utility is providing a 12470 to 480 volt transformer on their end and providing a temporary step-up transformer from 480 to 4160 at our service. The conduit, wire between the transformers and metering enclosures will be installed and owned by us.
Is the temporary transformer and wire Utility equipment or customer equipment during this temporary period of 2 to 5 years?
The Utility feels that the primary fusing on the 12470 and 4160 is sufficient to protect their system. Our engineer is concerned about our liability if we do not provide over current protection for the step up transformer.
Is there a specific NEC reference requiring over current protection for the step-up transformer in this scenario?