Motor MCA
Motor MCA
(OP)
Hi guys,
I was checking a single line diagram and it shows a motor of 17.9 MCA, 600V, 3-phase.
What does MCA stands for and how is it calculated?
I was checking a single line diagram and it shows a motor of 17.9 MCA, 600V, 3-phase.
What does MCA stands for and how is it calculated?






RE: Motor MCA
They use this for package equipment that may have multiple motors. It should be the sum of the motor full load amps plus 25% of the FLA of the largest motor.
"An 'expert' is someone who has made every possible mistake in a very narrow field of study." -- Edward Teller
RE: Motor MCA
RE: Motor MCA
So there may not be a formula for the "outsiders", but if you know the details you can calculate the ampacity required per Code.
Very reason MCA are given by the manufacturers is that you do not have to calculate and it does meet the Code. All you have to do is look up the correct data (column) for the combination/features you have.
RE: Motor MCA
RE: Motor MCA
RE: Motor MCA
For factory assembled equipment, manufactured published data is permitted to be used to size the conductors and overcurrent protection devices.
RE: Motor MCA
You will also see from some manufacturers, the "RLA" given, which is "Running Load Amperage", which is the actual expected running current under normal operating conditions. This would be what we include in our load summaries.
Regards,
EEJaime