SC CALCS NEEDED ON EXISTING INSTALLATION?

[tbassler_99]

I did a tenant finish on a core and shell. all panels provided by landlord.

I did no SC calcs.

My plans got rejected with the following comments:

"1. E.10 NEC 110.9 & 10 need point to point AIC to panel board and controllers & Hvac equipment until below 5Kaic."

"5. E3.0; NEC110.10 Verify SCCR rating is below listing." E3 is a lighting sheet.


So I have to do SC calcs to every HVAC equipment off of this panel? This is a shock to me. There are heat pumps, fan coils with electric heat, and exhaust fans on this panel.

this is new to me. None of these comments seem relevant or correct, Has the code passed me by?































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1. E.10; NEC 110.9 & 10 need point to point AIC to panel board and controllers & Hvac equipment until below 5Kaic.

 

[kwired]

My guess is your HVAC equipment is marked 5 kAIC (many are).

I guessing they want you to prove there is no more then 5 kA available at that equipment.

 

[templdl]

My guess is your HVAC equipment is marked 5 kAIC (many are).

I guessing they want you to prove there is no more then 5 kA available at that equipment.

Yup, 5ka is a default when the e we uipomernt is not to combination tesdtef and labeled we ith a kaic. This is common with enclosed motor control. If you fierld assemble a NEMA 1 enclosed combination motor starter using the same components as an listed enclosed combination starter the listed starter will have a UL label on the inside of the enclosure with its rating as it enclosed control was tested with those components inside that enclosure. The enclosure is an important component in the testing. If the HVAC OEM did not go through the procedure to actually have their assembly tested and settled on the 5ka as a default. Also, kaic implies that there is a OCPD which interups and clears a fault. If there is no OCPD thern I would think that the 5ka would be referring to a withstand rating which is the max allowed unless otherwise tested and listed.

 

[tbassler_99]

CODE REFERENCE

CODE REFERENCE

Yup, 5ka is a default when the e we uipomernt is not to combination tesdtef and labeled we ith a kaic. This is common with enclosed motor control. If you fierld assemble a NEMA 1 enclosed combination motor starter using the same components as an listed enclosed combination starter the listed starter will have a UL label on the inside of the enclosure with its rating as it enclosed control was tested with those components inside that enclosure. The enclosure is an important component in the testing. If the HVAC OEM did not go through the procedure to actually have their assembly tested and settled on the 5ka as a default. Also, kaic implies that there is a OCPD which interups and clears a fault. If there is no OCPD thern I would think that the 5ka would be referring to a withstand rating which is the max allowed unless otherwise tested and listed.

Where is this required in the cide?

 

[dkidd]

See OP for Code reference.

 

[kwired]

Where is this required in the cide?

See OP for Code reference.

I agree, 110.9 & 110.10

tbassler, if you have equipment only rated to withstand 5kA but supply it with a circuit capable of delivering more then that there is higher risk of that equipment having a catastrophic failure if it is subjected to carrying short circuit or ground fault current.

The problem is the equipment may be able to handle more but often when something is rated 5kA it means it hasn't been tested and 5kA is of the default level in that scenario.

 

[templdl]

I agree, 110.9 & 110.10

tbassler, if you have equipment only rated to withstand 5kA but supply it with a circuit capable of delivering more then that there is higher risk of that equipment having a catastrophic failure if it is subjected to carrying short circuit or ground fault current.

The problem is the equipment may be able to handle more but often when something is rated 5kA it means it hasn't been tested and 5kA is of the default level in that scenario.

It is very common for for many not wanting to hear/know this answer.