Nobody looks it up. The 4522 lamp is usually used in a swing-down lamp. The
swing down lamp has a motor to drive the lamp up or down.

The lamp is 12 volt, 250 watt, something the guesser at 9 amps (if for a 24
volt plane) would have realized if the system voltage of the plane had been
given, so the current draw for the lamp along is a nominal 20 amps.

If the motor circuit is not opened by the switch/relay built into the light,
the combination of the lamp current and the motor current will pop the breaker
every time, in a short time.

Yes, check the amps with a current meter, and please do not let the motor run
long in the test or it will burn out.

Neal