SHOCKING Princeton

[Richard]

Hi, I got a small shock from my SF Princeton when I was touching my guitar and groping around a gas space heater (which I believe is grounded through the gas line, it has no electrical connections). I have installed a 3-wire cord and disconnected the ground switch. I tested for continuity from the plug to the chassis and it was only present at the ground, I also checked the input on my pedal board to the ground with the same result and the tried to find a voltage between my guitar and the heater.

Basically I can't seem to find any way to recreate the problem to fix it. Are there any other tests I can perform? How do I check that the three wire power cord is wired properly? I'm pretty sure it is as I recall being pretty cautious and double checking the wiring. My pedals are powered through a powerstrip plugged into the same Furman Rackrider as my amp. Is it possible for a voltage to build up as the amp has been on longer and the problem "resets" when I turn it off. I did the work on my amp a couple of months ago and this is the first problem I've had.

[bob p]

did you test the outlet with a circuit tester, and test for continuity between the space heater chassis and the ground circuit in the buildilng?

[Rob Mercure]

"I tested for continuity from the plug to the chassis and it was only present at the ground," - I really don't understand this statement - are you stating that there is continuity from the grounding prong of the power cord to the chassis or not? After all this is how you "check" it - touch a DMM set on "ohms" to the large round prong and to the chassis and expect almost "0" resistance.

But I'd also do the same from the grounding prong of your power strip and the same prong on the "rack rider" to the chassis. And, are you sure that the outlet you're using is properly grounded? The narrow blade is the "hot" while the wider blade is "neutral" which should return to the same electrical potential as the grounding prong. Setting your DMM on AC - 200 VAC scale is common - you should get 120 VAC +/- from both the neutral and the ground to the hot and no voltage between neutral and ground. If there is no voltage reading between ground and hot you have an ungrounded outlet. If there is any reading between neutral and ground you've probably got a miswired outlet.

Rob

[Richard]

I read 0 ohms from the grounding plug to the chassis and no continuity between the hot or cold blade of the plug to the chassis. I realized I checked DC between the amp and heater and just checked AC and got 62V so I'm thinking I have a short on the secondary of the PT, maybe the bias supply (as it's not 120 )

[Richard]

Hi just tested between ground of my power cord and the heater and got 62 volts so the good news is my amp is okay and the bad news is my house (or my landlady's house) is jacked.

[R.G.]

Hi just tested between ground of my power cord and the heater and got 62 volts so the good news is my amp is okay and the bad news is my house (or my landlady's house) is jacked.

Actually, the bad news is that you are living in an electrocution hazard. If the house wiring is that bad, you are at risk of dying from an unseen hazard.

Go to a hardware store and get yourself an outlet tester plug. Try it on the outlets in the house. If it shows bad, tell the landlady about how you're afraid that you might get electrocuted. That should get immediate response.

If it does not, pay an electrician to inspect yourself, and if the result is "bad house wiring" set a time table with the landlady to get it fixed and move if it doesn't get done.

Death is so final.