As you are saying here, you have more chances of getting shocked plugging in your toaster at home than AGPU power to the plane while standing in a puddle of water. Those plugs have some SERIOUS rubber on them.
As for the continued debate on power messing up the plane...
When you plug in ground power, it sits at the receptacle if the switch is out, going nowhere. If the switch is in (either because you push it now or it was left in prior), where does the power then go? To the GCU. Where it is tested and monitored. If the phase rotation is correct, and the voltage and Hz. withing required ranges, and if the dual current transformers inside don't detect a spike in amperage (feeder fault or "short"), THEN the GCU allows power to go to the plane.
Now, it's true that a split second of power application is required in order for the current transformers to detect the feeder fault; electricity HAS to flow for there to be a "short" detected. But again, whether you push the switch in after power is applied, or the switch is already in, the same thing happens.
Basically, all that switch does is keep ground power away from the GCU, not the airplane. If you plug in "bad" power, the GCU SHOULD, in most cases, do its job and protect the plane. But you as a button pusher have no idea if said power is good or bad when you press the switch, and the same thing will happen either way. The GCU works about 1,000 times faster than your finger can, and either saves the plane or fails.
And the only power that is applied to the plane is 115V, 3 phase 400 Hz. Enough so that if you DID get hit by it, it would get your attention. Having been shocked at least 10 times in my career, I can honestly say it's the most fun I never want to have again, but it's not the end of the world.
Back to my original issue with this new switchology... I have been taught since day one to push the switch out to agree with condition. If the company wants us to do something different, it needs to be in writing, not just coming from LCAs as we fly with them. Supposedly, this new switch thing has been out for months, and I only heard about it last month.
Originally Posted by
JesuitValen
The 900 has left that switch in since 07 when I started flying them. Some of the older mesaba guys can speak to the 200 in msp i would think.
If this procedure is so awful for the plane and the ramp crew, then you should have no problem proving it on historical data.
Furthermore, as an ex rampie, the plug is attached and THEN power is added. While the giant isolated plug covered in rubber is worked in and out of the plane sometimes by a careless rampie or two with power applied, theres little chance of that AC power arcing to hands.
Is it possible Pinnacle guys made something up and DTW MX guys on here are simply echoing it because they fail to remember the jetbridge supplied powercarts are garbage? No other airport in the country has been able to fry a crj like the worthless airport authority provided external AC.
I like the 480VAC story though, can we get more of those tall tales in the future?