Electrical Problems ???

[heeman]

^ yes, the code changed quite a few years back for 240V Appliances/Devices from a 3 to a 4 prong plug/receptacle.

 

[malsackj]

So if you look at how a second panel is connected and the common is not bonded to the ground.

http://www.middleatlantic.com/~/media/M ... Paper.ashx

My distro for sound support and bands is 4 wire connection but the common and ground are not connected.

 

[malsackj]

So here is a new write up by Mike Sokol on old wiring and problems.

http://www.prosoundweb.com/channels...c-outlet-testing-what-it-means-for-pro-audio/