Min Ckt Amp also min breaker size?

[ryan_618]

Re: Min Ckt Amp also min breaker size?

Bob, I agree. I think Dillon was trying to express where the nameplate value comes from, which I think comes from that section.

 

[roger]

Re: Min Ckt Amp also min breaker size?

Allen,

Fuse to max breaker listed by manufacturer and supply within guidelines of min no inspector can tag you on this install.

no inspector can tag you for fusing to the minimum either, read 110.3(B). You may have some warranty headaches, but no code violation

JW, you have a typo in your code quotes.

Roger

 

[jwelectric]

Re: Min Ckt Amp also min breaker size?

Originally posted by roger:


JW, you have a typo in your code quotes.

Roger

Thank you Roger that should have been 440.22 (B)

 

[roger]

Re: Min Ckt Amp also min breaker size?

JW, you're welcome.

Roger

 

[milwaukeesteve]

Re: Min Ckt Amp also min breaker size?

Conductor sizing- based on min ckt amps (125% of compressor motor + all other motors)
Disconnecting means (for disconnecting only, no circuit protection) - based on 115% of the sum of all Running Load Currents (RLC)
Short Circuit and Ground Fault(SCGF) Protection- based on 175% of compressor RLC. If not sufficient for motor starting then 225%
Overload Overcurrent protection- based on the motor compressor RLC, AND wiring method.

If overloads are used(@140%), then SCGF protection is needed (@175%)
If HACR Breaker or Time delay fuses are used @125%, then NO seperate SCGF protection is needed.

 

[allenwayne]

Re: Min Ckt Amp also min breaker size?

Roger all I meant was that allowed wire for min, and fuse for max.The manuf.states what the min ampacity wire will be and the max ocpd will be.
You have to meet the max breaker size and be between the min and max on brabch circuits.If allowed I would never wire in 14,# 10 is my miimaL
bUT THEA`TS JUST ME. Watch those TRANE units get spececs,a normal 5 kw that was ok for #10n=mMight shownup as a 32 amp unitThgen what???