you can use ohms law

What is the voltage and the resistance of the coil you then can work out the current draw

The soleniods that we use have 3 wires one is ground, the other is holding voltage and th last one is the pull in voltage, So you put power to the pull in (this pulls the soleniod in) and then the holding volatge takes over, then the power is removed from the pull in. The ones we use can draw up to 30amps only if hold the holding voltage is powered up first.

What type of solenois are the ones you are using ?