HVAC engineer just gave me this mini-split heat pump and fan coil unit combo. The system will be wired as one on a 208V single phase circuit. How do I calculate the load for it? Based on the MCA? Or based on the heating and cooling demands with power factor.
Load Calc for Mini-Split Unit (VA)
- Thread starter liam913
- Start date
HVAC engineer just gave me this mini-split heat pump and fan coil unit combo. The system will be wired as one on a 208V single phase circuit. How do I calculate the load for it? Based on the MCA? Or based on the heating and cooling demands with power factor.
MCA for branch circuit load, 12 amps is not much. Seems like very efficient unit.
For the service load calculation and the first unit I would use the MCA, as that should cover any configuration in the package.
If you have n number of equal sized units going on one service/feeder for article 220 I would start to dig into the Maximum Power numbers, that Heating Maximum Power Input of 1770W and the power factor look like a starting point, the number of indoor units and options (block heaters) may need to be counted individually in that case.
JoeStillman
Senior Member
- Location
- West Chester, PA
- Occupation
- Electrical PE
MCA is ok for a load this size. But when your service calc finally says you need a 201A service, you might want to sharpen your pencil and dig out the RLA's and FLA's of all the motors. Typically, there is
- A compressor (use the RLA)
- An Outdoor (condenser) Fan (use the FLA)
- One or more indoor fans. (use the FLA)