What is a full load amp, and is it different from the standard ampere?

Question

festinger · Answer

Full load amp defines the maximum current the device, usually motor, will pass through the device during starting up.

This is because as the device starts up, the current going through it increases until a maximum, called the full load amp.

The standard ampere is probably referring to the running load, which is the current the device uses after it has started.

The full load amp is important as it helps design what fuses or circuit breakers to use etc.

isaiah.feynman · Answer

Can you use the full load amp to calculate the voltage of a device?

festinger · Answer

I would rather you use the running load, that's is what is used during steady state.

isaiah.feynman · Answer

Ok. I'm trying to calculate the power of my fridge and all I got is the full and amp and the voltage.

isaiah.feynman · Answer

Can the power be calculated using these values?

festinger · Answer

P=VI. Use amp and the voltage.

shane_b · Answer

I agree with @Festinger.  For calculating power usage on household equipment you can ignore the FLA ratings and just use the normal/running amperage rating.


Just so it's clear, an amp is an amp.  For single-speed motors there are typically two amp ratings on the nameplate:

1) Full Load Amperage (FLA) - Indicates the maximum current you should expect from the motor while it's ramping up to speed.  It's commonly used to determine the type and rating of motor circuit protection devices.

2) Normal (running) amperage - The max current it should draw while running at normal load, after start up.


And as a final note, you can buy a household power meter for about $25 USD which can be useful to have if you want to take actual readings.