2 prong + surge protector

[alien]

An OT question to a forum I trust

My house(USA) has 2 prong outlets. I rent so I cant alter the boxes--but does plugging a surge protector in the outlet and then my amp into the protector provide any protection?

thanks

[defaced]

No. A surge protector protects your electronics devices from surges in the mains lines. What you need is a path to ground to protect you in the event of a short. Are the center screws that hold the outlet plates grounded? Even if it's not a three prong outlet, the outlet itself and the box it's in (provided it's a metal box), should be grounded. From there you can use a three prong adapter and secure the metal tab to the screw that holds the outlet cover on. Check with your ohm meter, but this should give you a good ground.

[chipaudette]

In my house, the box itself isn't event grounded. So I called out an electrician and showed him my need for grounding when working on my tube amps. He said that swapping out my two prong jack for a GFI (ground fault interrupt) jack would give me the protection that I'm looking for without re-wiring my house.

A GFI jack are the kind that you should have already in your bathroom. They look like normal 3 prong jacks, but they have two little push buttons on them -- "Test" and "Reset". I believe that they work by sensing whenever the current flow between the two hots are not balanced (ie, a lot of current is flowing through you to ground instead of back through the jack). When the flows are not balanced, it cuts the power.

So, you could either swap out your existing jacks with GFI jacks (you don't need to change the wiring or the box...just the jack and the face plate) or you could buy a power strip with GFI protection. I have seen a few such power strips. The one's I've seen are like short extenstion cords (3-feet) with 3 outlets on the end. The plug part that plugs into the wall has the "test" and "reset" buttons.

Good luck!

Chip

[Don Moose]

Sorry, Chip, but it's called a GROUND Current Fault Interruptor. It detects current flowing in the GND wire and shuts off.

Gotta actually have a ground connection for that to work.

If your boxes aren't grounded and there's no ground wire in the box, your electrician lied to you about there being any chance of one of these magic boxes doing anything but costing you money.

Alien - if your work area is near some plumbing, AND the cold water pipe is grounded, you could clamp a ground wire to that. Then you run the wire along the baseboard to the one outlet box you most need grounded.

Ugly, but effective.

Hope this helps!

[defaced]

A ground fault circuit interrupted doesn't just trip when there is a fault to the ground wire in the wall, it will trip if there is a ground fault anywhere because it senses the current flow on the hot and neutral lines:

A GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one-thirtieth of a second.

Suppose a bare wire inside an appliance touches the metal case. The case is then charged with electricity. If you touch the appliance with one hand while the other hand is touching a grounded metal object, like a water faucet, you will receive a shock. If the appliance is plugged into an outlet protected by a GFCI, the power will be shut off before a fatal shock would occur.

http://www.howstuffworks.com/question117.htm
http://www.cpsc.gov/cpscpub/pubs/99.html

If you're not near any water pipes, you can also fish the ground wire out a window or other hole in the wall (cable, telephone line) and find a ground. Generally, there is a metal pole sticking out of the ground that you will find wires bolted to, that is your grounding pole. Look near your utility boxes.

[alien]

good info guys

How can I test if the center screw is grounded to the box?

thanks so far guys

[Don Moose]

Hmm. Consider me corrected.

Still no help with surge protection, but a safety benefit nonetheless.

[defaced]

Grab an outlet tester from the hardware store and a three prong adapter. Plug the outlet tester into the adapter and then plug the assembly into the outlet. The tester will show an error by not having a ground. Now connect the tab to the screw. If the error clears, then you're good, if not, then you need to find a different way to ground the three prong adapter.

[alien]

can I use a multi meter?

[Jag]

You can use a multi meter to check if the screw is grounded to the box but, that won't tell you if the box is connected to your mains ground which is just as important.

[nimble2]

Your question should be about "If I can get shocked and killed by old 2 prong outlets" instead of, if a surge protector will work with them.

Back to the question at hand.
Yes and No
A 1 way surge protector will NOT work with them.
(MOV device between ground & hot)
A 3 way surge protector will work with them.
(MOV device between all post, ground to hot, ground to neutral, hot to neutral)

[alien]

Your question should be about "If I can get shocked and killed by old 2 prong outlets" instead of, if a surge protector will work with them.

That would be my question if I was afraid of getting killed--but Im not. Personally I think there is mass hysteria on all things electrical on the internet concerning dying. Its like this morbid obsession. Your much more likely getting killed going to work everyday or even winning the lottery.

I want to protect my computer, amp, and the like.