View Full Version : Q about grounding

08-08-2007, 05:53 AM
In our continuing effort to solve our power woes (our electronics keep getting zapped during storms) we finally got an electrician out who discovered that the pole at the street, which has a transformer, should have a line going from the box at the bottom into the ground but does not. This is interesting to me since we called the power company out last week and they told us everything was fine and we are expecting a bill from them for their service. The electrician will call the power company and get them to address this. He also will get us an estimate for a whole-house surge protector. So my question is whether this failure to have a ground wire at the pole was the likely culprit for our frequent power surges. As background, the house is 2.5 years old and we have always had power outages but recently started having things get fried (garage door openers, boiler Taco box, etc.)
Thanks for any input--

Bob NH
08-08-2007, 06:36 AM
You might want to compare the cost you are getting from the electrician to the cost you can buy one for and do it yourself.

If you search that famous auction site for QO surge (check search title and description) you will find units that plug into a Square D QO main panel like a 2-pole breaker. I suspect that you can get one for less than $55 including shipping. It will take you about 10 minutes to install it in a panel.

I have not searched for other brands but the price should be similar.

08-08-2007, 06:57 AM
The things to check on surge suppressors are: response time (under 1ns is good); clamping voltage; amount of joules it can absorb; and some sort of indicator that it is still working (outside of the box so you can see it). It is also nice if they can suppress some line noise as well as the phone line and cable entries. The suppressor I bought for my home entertainment system can absort nearly 4000 joules to give you an indication. www.smarthome.com (http://www.smarthome.com) has some you can review to get an idea of what is out there; then you can search around for others and pricing.

08-08-2007, 07:15 AM
I have a definite bias against the famous auction site, but that is another story.

BUT, over the last 18 months, there has been a major scandal involving counterfeit Square D breakers. Major national distributors were involved, unintentionally or not. You would have to assume that ANY Sqaure D on an internet site is counterfeit. Problem was, not only are they counterfeit, but of course they are lousy quality, and catch fire!

08-08-2007, 08:00 AM
Thanks all for the info on the suppressors - I will definitely do some homework - does anyone have input on whether the lack of ground on the pole was causing us to get hit so often?

Speedy Petey
08-08-2007, 02:16 PM
Thanks all for the info on the suppressors - I will definitely do some homework - does anyone have input on whether the lack of ground on the pole was causing us to get hit so often?
It's not at all likely. This has nothing to do with the power quality on the secondary side of the transformer.

08-08-2007, 02:30 PM
If you have ground rods at your input panel, it probably doesn't matter all that much. A loose neutral would be a major problem, though. At your input panel, you tie the neutral to the ground. From a safety viewpoint for the lineman, the lack of a ground at your powerline might be a factor, but that is their problem.

08-08-2007, 08:53 PM
Installed a sony survail. camera with 5"screen. Kept burning out during storms.
Area is noted for low voltage ,when we have these wind storms. Area has many trees that cause line problems in high winds! Was told LOW voltage raises AMPS that Kills ELectronics!

08-09-2007, 08:56 AM
Brown-outs can cause problems with many devices. When installing my central a/c, the installer mentioned a device by (I think) IDC, and I installed one. This monitors the incoming voltage, has adjustable working range, and controls a relay when power is outside of the parameters, it disconnects what you have connected. I have it set to disconnect the 28vac low-voltage signals from all functions, preventing it from turning on the compressor, heat, or fan unless the voltage is both stable and within spec. It looks to see how stable it is, and if it isn't, gives a user adjustable time-out before it will consider again while the main vac input is active. This helps during a power outage when things first turn back on where the power can be bouncing all around. Anyways, seems to work. I bought it at Grainger. I guess I could have connected it to a contactor, and open input power if it detected a fault, then the main board wouldn't be subject to damage, but didn't want a contactor on all the time, and if you had a bad situation, it might not engage when you did if you used NC contacts.

08-11-2007, 04:59 AM
On surge suppressors.

Proper installation is important.
Straight as possible leads (avoid tight bends).
Leads as short as possible.
Cable tie the leads together from the CB to the TVSS.
Multiple level suppressors, one at the panel one at the load.
As noted above buy good TVSS and power strip with working indicators.

The ground at the pole depends might affect the possibility of an impulse damaging equipment if there are lighting arrestors on the pole (seldom used in residential transformer installations.)

Nothing will protect you 100% all you can try to do is minimize the impact. If you are in an area prone to lightning hits, you might consider the ultimate protection unplugging sensitive electronic equipment.

08-22-2007, 06:32 PM

first, the electric company came back out and confirmed that the pole at the street does have a grounded wire - it was there all along but sunk in to the pole and covered in creosote. So our linemen are safe!

second, here's what our electrician installed


(1200 joules, less than 5 nanosecond response time, maximum surge current 48,000A)

I've spent some time researching joules and such - man, this electrical stuff is mystifying!!! I'm going to assume that this unit is okay, and if it blows up in the next storm, we'll know we need a stronger one (~:

We will also install some high quality surge protectors on the tv, computer and garage door openers - just to be sure!

It seems we are just in a location where we are more prone to strikes. The electrician says the past two years have been crazy for him with calls from people getting hit during storms.

Thanks to everyone for your input--

08-22-2007, 08:50 PM

We will also install some high quality surge protectors on the tv, computer and garage door openers - just to be sure!

Thanks to everyone for your input--

I wait until Christmas and pick up high end consumer battery backup / surge suppressors. They are really cheap in early January,

08-23-2007, 06:49 AM
Unfortunately, there aren't that many thunderstorms in January, although it happens. UPS are nice, but a good surge suppressor is cheaper. The one I have for my tv, etc. has a five stage noise filter and something like 4800 joules of energy dissipation capability, a decent warranty for attached equipment, and cost in the range of $100. You can buy bigger units. For comparison, an el cheapo plug strip may only have in the order of 200 joules of energy dissipation capability and won't have any noise suppression.

08-23-2007, 08:04 AM
is there an answer to the question of how many joules is enough joules????