Machine Power Supply Specification

[GraemePeek]

I would like to know what most people do when they spec the power requirements for a machine they have manufactured. Do they add up all the motor plate full load data or call out the sum of actual loads drawn by each motor. We want to standardise the way we tell our customers what size supply to give one of our machines.
Is there a standard or an organisation to reference?

 

[RajT]

On the assumption that your machine has both static and motor loads, it is best to list all loads in a tabulated style and fill in data to suit.
ie
Load type
Voltage3/1ph
Nameplate ratg
Max absorb power for motors
Diversity ie continous/intermittent/standby

You can also test the machines on load and note the current drawn in the worse case and work out the power required using kW= *3VICos phi andc state on the nameplate the max absorbed power so the supply fuse rating can be selected accordingly.

 

[jbartos]

Suggestion: Also practical is to state the total input power requirements, e.g. Voltampere, Power Factor, or Watts, Power Factor. If you obtain the values by calculations, it may be a good idea to verify them by measurements. Additionally, it is very usefull to state Circuit Breaker (Thermal Magnetic) rating or Fuse (fast or time delay) rating for the machine.