mshields
Senior Member
- Location
- Boston, MA
A number of parts to this question...
1) I've got a 1500KVA, 13.2kV to 480Y/277V pad mounted transformer with under oil short circuit fuses plus full range bayonett fusing on the primary. This feeds a 2500A 480V service feeder into my facility (which happens to be a hospital). My protection for my secondary conductors is the main breaker of the interior main service switchboard.
a) Does it matter that I am primary metered and that the transformer is owned by the facility?
b) I assume I'm ok thus far insofar as I've employed Article 230.90 (A) to protect these secondary conductors.
Now - We're being asked if we can add a Zenith ZTG switch down stream of the transformer but prior to the service entrance circuit breaker to act as a manual transfer switch. The purpose of which is to create a point at which we could plug a temporary generator if the transformer failed on us. Now it seems to me, I've muddied the waters and I need to have some overcurrent protection as part of this switch.
The switch is made from contactors not breakers so this would be mean the addition of a 2500A breaker.
Thoughts? Do I need that breaker?
1) I've got a 1500KVA, 13.2kV to 480Y/277V pad mounted transformer with under oil short circuit fuses plus full range bayonett fusing on the primary. This feeds a 2500A 480V service feeder into my facility (which happens to be a hospital). My protection for my secondary conductors is the main breaker of the interior main service switchboard.
a) Does it matter that I am primary metered and that the transformer is owned by the facility?
b) I assume I'm ok thus far insofar as I've employed Article 230.90 (A) to protect these secondary conductors.
Now - We're being asked if we can add a Zenith ZTG switch down stream of the transformer but prior to the service entrance circuit breaker to act as a manual transfer switch. The purpose of which is to create a point at which we could plug a temporary generator if the transformer failed on us. Now it seems to me, I've muddied the waters and I need to have some overcurrent protection as part of this switch.
The switch is made from contactors not breakers so this would be mean the addition of a 2500A breaker.
Thoughts? Do I need that breaker?