ELI5 Bench Testing

[Chattin35]

So, here's a question for the forums that's going to highlight my ignorance of the electrical system. How do you bench test avionics? I'd like to make sure my lights, trim, EFIS, etc. are working correctly before installation?

Here's what I know... you need a 12V DC power source and some kind of ground. That's about it, haha.

So, what can you use as the power source?
What makes a good ground?
Do you need to connect any fuses or breakers?
How do you keep from frying your expensive elec equip?
And, what's the best way to set this up on the workbench?

Thanks!

[Mich48041]

The most important thing is to pay attention to polarity. Reversing positive and negative will destroy expensive avionics. You could use a power supply or a battery. If buying a power supply, get a good quality with a filtered output (small AC component). Fusing the source of power will protect it and wires against accidental short circuits. A shorted battery could vaporize wires and cause blindness or burns. The negative battery terminal is usually connected (grounded) to the airframe of a metal aircraft. Testing on a bench only requires a positive and negative power source. It is not necessary to actually connect the negative to ground. Expensive equipment can be destroyed by reversed polarity or by too high of voltage or by connecting power to the wrong terminals. Make sure everything is hooked up right before turning on the power.

[Chattin35]

Thanks Joe. Sounds like you're using a switch in the circuit?