Captain Kirk, can you save me?
Dear Fe26,
I know all kinds of shit about all kinds of shit, but not much at all on electricity. My question is this: I have a house from the 1950's. All of the electrical outlets in the house are of the two-prong variety (although I understand in a house this old they're still likely grounded?). I'm also gonna buy a tester tomorrow. I have a bunch of those 2-3 grounding adapter thingies.
My concern is primarily due to getting my new guitar amp here tomorrow. I don't want to fuck around and take chances with it. What do I need to know, what do I need to do?
To boldly go where lots of men have gone before...
Load"*",8,1
The 3rd prong is for Chassis ground, so you don't shock the shit out of yourself when touching a metal case.
http://www.howstuffworks.com/question110.htm
What happens if you cut off the ground prong or use a cheater plug so you can plug a three-prong appliance into a two-prong outlet? Nothing really -- the appliance will still operate. What you have done, however, is disable an important safety feature that protects you from electric shock if a wire comes loose.
Captain Kirk, can you save me?
Right, I get that. So consider how that works when holding a guitar connected by a 1/4" jack to an amplifier that uses lethal voltages and you'll see why I'm taking slightly more than usual concern about wanting the ground to not be me.
To boldly go where lots of men have gone before...
Nordic Warrior
I think it would only be a problem if there was some type of equipment defect that exposed the electrical current. I wouldn't worry too much about it, but I would be cautious with your wires and whatnot.
Load"*",8,1
I don't know if a UPS might provide some kind of chassis ground. I'd guess not.
If the plug is on an exterior wall to your house, you can place a grounding rod outstide of that wall and run a ground wire into that electrical box. You'll have to replace the outlet with the 3 prong of course.
Last edited by gamevet; 26 Apr 2011 at 12:44 AM.
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If your outlets only have two prongs, then they probably aren't polarized either. If both slots are the same length, they are not polarized. That's not really a big deal most of the time, but you may as well get properly wired outlets. They cost next to nothing to replace.
If your wiring runs through metal conduits, then you may be able to get away with just connecting the ground terminal on the outlet to the junction box to get everything grounded properly.
You can get little plug-in testers that light up with different codes to let you know if you're wiring is wrong.
You can kick your own ass on an ungrounded amp. His caution is warranted.Originally Posted by Gohron
Captain Kirk, can you save me?
They ARE polarized. Or at least different lengths.
To boldly go where lots of men have gone before...
I mean this in the nicest way, but are you fucking with me? You've asked a life and death question in the vaguest way possible.
You're going to have to give me more information. Like seriously, how old is your house, and do you have any idea what year code it is up to? Is it modern but just two prong? Or is it 1920s bizarro shit where raw aluminum wire is connected to lead and copper pipes to form a ground?
And how old of an amp are we talking about? Do you know the model? Does it use tubes?
You probably won't have to worry about a solid state amp. But old tube amps can dump a lot of 60 hz hum on that chassis if it doesn't have a connection to earth ground. And if it has a polarity switch on it, it may be dropping 120 Vac straight to the chassis. Which will connect to the 1/4 jacks, go up to the guitar and through you if you make a connection to ground
It's a 1972 Bassman 10.
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