Load calc in VA when only given MCA?

[liam913]

I know the MCA is only provided for wire sizing. I need to get load calcs for different mechanical HVAC items. Some items give me both FLA and MCA and then some just give me MCA.

What do I do if only given MCA??

 

[ron]

MCA (Minimum Circuit Ampacity) is a value used to determine the minimum wire size needed to safely carry current for a motor or electrical system, while FLA (Full Load Amps) is the rated current a motor draws at its full load operating condition. MCA is typically 125% of the FLA.
With FLA, you can then calculate VA

 

[don_resqcapt19]

The way I read 220.50(B) you need to use the MCA in your load calcs.

(B) Air-Conditioning Equipment.
The conductor sizing requirements specified in Part IV of Article 440 shall be used to determine air-conditioning loads for hermetic refrigerant motor-compressors.

The conductor size is based on the MCA