Sierra RotorCraft Club

The goal for today was to finish wiring all three electrical systems (pneumonic, hydraulics, yaw) to there individual power switch and receptacle. So to recap, the main power from the electrical generator goes to the simulator circuit breakers, then to the power switches and on to the receptacles.

The purpose of the receptacles is to be able to plug and unplug each electrical system for testing purposes and or wire replacement if one goes bad. Each electrical system has a plug that is to be plugged into there respective receptacles.

Testing time – Since at this time we are only working on the pneumonic system (air), I only connected that system to it receptacle. Plus I still need to buy plugs for the cords of the other two systems.

One of the things I wanted to know is how much current/power is the air compressor drawing. The problem we are having is that when the compressor kicks back on from a full tank of air, it pops the generator circuit barker. Note – that the circuit barker in the simulator does not trip when it is supposed too and needs to be replaced.

So the first thing we did was to measure the current and power usage (watts) out of the generator with and without a load. The test shows that the generator is putting out 120 volts with no load.

When the power switch to the air compressor is turned on, the generator is still outputting 120 volts with ~ 8 amps of current ~ 900 watts. But at the receptacle point (with a watt meter) the voltage drops to 107 volts at 8 amps, ~ 856 watts.

Since the power cord is 14 gauge and about 50 feet long, we think this power drop is due to the electrical cord, (since there is nothing else between the generator and the simulator circuit breakers ) absorbing 13 volts. So the next time we have a simulator day, I plan on using a 12-gauge cord.

As far as the air compressor is concerned, it requires 120v at 8 amps. However we noticed that the compressor is stalling out when it turns back on after about 20 pounds of air has drained out of the tank. When the compressor stalls, it is drawing over 20 amps, hence causing the circuit breaker to trip.

So for the next simulator day, in order to finish trouble shooting the pneumonic system, we will be connecting an external air compressor to the simulator. Hopefully, it will not pop the generator circuit barker and we can finish are work on that system.

As far as the simulator compressor motor, we my have to replace it.