Cockpitbuilders.com

Main => Builders Discussions => Topic started by: milezee on November 11, 2014, 06:01:50 AM

Title: Thank goodness for RCDs...
Post by: milezee on November 11, 2014, 06:01:50 AM
Or it all would have gone bang!

That is all  :o
Title: Re: Thank goodness for RCDs...
Post by: Trevor Hale on November 11, 2014, 06:11:59 AM
You ok?  Frig I hate hearing something like that....
Title: Re: Thank goodness for RCDs...
Post by: milezee on November 11, 2014, 10:00:17 PM
Yeah, fortunately it didn't go through me. Thanks for the concern.
I'm always super safe. The only time I get to work on the sim is when everyone is out of the house so I always triple check reality when messing with wires.

After disconnecting everything (and triple checking), I poked around with the multimeter. I had been fairly confident in my wiring and indeed it turned out to be the PC PSU I had been using for 5v+12v had a short. I've ordered some proper bench PSUs now as a replacement.

The upside is knowing that I can have some confidence in the RCDs in my house. They are quick to trip, as they should be after reading the scary wiki article on ventricle fibrillation!


Take care y'all - don't do anything stoopid.
Title: Re: Thank goodness for RCDs...
Post by: blueskydriver on November 12, 2014, 01:47:32 AM
Had to look this one up and RCD's are the same as Ground Fault Interrupters (GFI or GFIC) circuit breakers. GFIC is great for protecting humans/animals from the shock, but the Arc Fault Interrupter (AFI or AFIC) is actually better in preventing fires in the use of the simulators, IMHO.

The AFIC stops the current when an ARC occurs, but you get micro arcs all the time when you flick a switch or a component changes the current in small amounts. However, the AFIC is "brain smart" so too speak, in that it has to reach a threshold in order for the arc to trip the AFIC breaker. Of course the GFIC is going to be better in areas of water or fluids near the power circuit and where people/animals will be, but it is not as sensitive as the AFIC concerning arc outs, so you could have a good fire start before the GFIC even trips off.

When I changed the sim room around and installed 11 AFIC circuits and 1 GFIC (for an outdoor pole light), I thought it was too costly, but I chose to spend the money anyway, just to be safe someday. Albeit, the AFIC cost $45 US each, where the GFIC was about $12, I was happy I had the AFIC's hooked up for the simulator...when that someday happened.

Some might remember this story back a year ago; I had the MIP, center, upper display power board burnout and it was the AFIC that saved the day. I was out of the sim for a bathroom break, so everything was running without me present just for a few minutes. Once I got back in the cockpit I could smell the burnt board...

After pulling the display apart and seeing the blackened component on the power board, I couldn't help thinking how grateful I was the AFIC tripped off. If the GFIC was in use it would've kept burning since the grounding was not the fault, it was an arc out, like an arc welder...fast and a hot spark, so just a brief moment of arcing was all it took for the burning to happen!

So, AFIC all the way for me and a couple new smoke detectors inside and out of the sim, as well as a fire extinguisher made for all types of fires attached on the FO Circuit Breaker Panel wall; just like it's supposed too be in the real B737.

Otherwise, I am glad to hear that you or no one else got shocked or that your sim went up in a blaze...

John