Metering Breaker Interrupting Rating

[yesterlectric]

I am doing a tie in for a solar installation and the general contractor wants us to tie in on the line side of the 4000 amp disconnect and put a building load meter with voltage monitoring on the line side of the disconnect as well. I have not verified the total possible short circuit current deliverable by the transformers, but the current 480 volt switchgear is rated at 150K amps. I am needing to install a circuit breaker between the voltage input taps and the meter. i am finding it difficult to find a 5 amp breaker with an interrupting rating greater than 14K amp. The "engineer" on this project seems less knowledgeable than myself. What is usually done in this circumstance? Are specialty fuses required? Is this typically not a concern?

 

[BAHTAH]

I am doing a tie in for a solar installation and the general contractor wants us to tie in on the line side of the 4000 amp disconnect and put a building load meter with voltage monitoring on the line side of the disconnect as well. I have not verified the total possible short circuit current deliverable by the transformers, but the current 480 volt switchgear is rated at 150K amps. I am needing to install a circuit breaker between the voltage input taps and the meter. i am finding it difficult to find a 5 amp breaker with an interrupting rating greater than 14K amp. The "engineer" on this project seems less knowledgeable than myself. What is usually done in this circumstance? Are specialty fuses required? Is this typically not a concern?

If you are looking to protect the meter you could look at the Class-CC Bussmann KTK-R 200Kaic rated fuses, they are used for industrial control and there is a fuse holder disconnect. Not sure if
that fits your needs, just a thought.

 

[templdl]

I am doing a tie in for a solar installation and the general contractor wants us to tie in on the line side of the 4000 amp disconnect and put a building load meter with voltage monitoring on the line side of the disconnect as well. I have not verified the total possible short circuit current deliverable by the transformers, but the current 480 volt switchgear is rated at 150K amps. I am needing to install a circuit breaker between the voltage input taps and the meter. i am finding it difficult to find a 5 amp breaker with an interrupting rating greater than 14K amp. The "engineer" on this project seems less knowledgeable than myself. What is usually done in this circumstance? Are specialty fuses required? Is this typically not a concern?

Yes, if were me I would be concerned. This is not a dinky 100a service. It is obvious you are concerned as you are asking for some guidance. Have you asked the general contractor if he will be liable for what he is asking you to do or should he get a qualified engineering firm to put together specifications for you to do the installation by.
It seems to me your general may not realize the implications of the installation of they just want to cut corners.
In any event you are wise in asking questions. Ask the general to give you a one line of what he wants you to do.