What should one look for in a "whole-house" surge suppressor?

Factual Questions
1

A recent thread has me motivated to buy a whole-house surge suppressor, (aka “transient voltage surge suppressor”). I have many electronic toys, some quite pricey. Homeowners insurance may pick up the tab on a worst-case zap, but it may not and that’s not an option anyway, thus prompting this question: What kind of specs should someone look for?

I recently picked up a battery-backup/surge suppressor for my computer. It rates at 550 va/330 watts/890 joules. I guess that’s about average for a wall battery unit, but what should one look for in a whole-house suppressor?

Here’s what the Chicago Sun-Times says about whole-house suppressors in general: “Whole-house surge suppressors are generally more effective than the ones you plug into the wall and then plug in the appliance or electronic device. Almost every electric item in your home now has some type of sensitive electronic component that voltage surges can damage.”

This Old House notes the a TVSS system doesn’t stop all of the overload, but notes, “Typically, whole-house suppressors are hard-wired to the service panel, a process that takes a licensed electrician about two hours. Whole-house systems should be rated to stop a 40,000-amp surge, at minimum. … Lightning-induced surges are the most powerful and most feared: A 200,000-amp jolt crashing through a power line will burn standard 20-amp wiring like a lightbulb filament.”

  1. Intermatic, Inc. sells a wholehouse surge suppressor for only $80, which seems crazy low. Specs:

Transient surge capacity - 1200 joules
Maximum surge current - 48,000A
Response time - less than 5 nanoseconds
Line to Neutral: 500 volts
Line to Ground: 500 volts
Neutral to Ground: 500 volts
Line to Line: 800 volts

  1. Leviton sells one priced at $215. Specs:
    Unlimited main breaker panel current
    Transient surge capacity - 950 joules
    Maximum surge current - 50,000A
    Response time - Instantaneous

  2. Home Depot sells one for $120. Specs:
    “Absorbs 2,700 Joules and 60,000 amps”
    http://www.homedepot.com/prel80/HDUS/EN_US/diy_main/pg_diy.jsp?prod_id=100396483&cm_mmc=1hd.com2froogle-_-product_feed-_-D27X-_-100396483

> Can someone give general guidance re: specs. The Home Depot model protects against 2,700 joules, but I’m wondering just how much protection that really is. Conventional wisdom is that nothing will protect against a direct lightning strike, but I’m looking to cover most every other scenario.

Please advise.

2

I have this unit: http://www.tesco-online.com/products/se/TES240R.htm mounted on my meter base.

It was installed by and is owned by my electric co-op. They charge me $5.95 a month. If it fails, by doing it’s job. they replace it with a new unit. It has two red LEDS on the outside. As long as they’re lit it’s “good to go”.

You might check with your electric provider to see what they might have to offer.

3

Having talked to experienced electrical techs, the $9.95 plug-in devices are useless, they claim. Maybe worse than useless, since they offer a false sense of security.

4

Two hours to install? That’s including drive time to your house, right?

If you know your way around the insides of a circuit breaker panel, installing one is about a 15 minute job. Of course, if you think a “bus” is something used by commuters, you’ll be better off hiring an electrician, but I can’t see how installing one could be stretched to two hours.

5

Here is the line of products offered by Square D.

6

Perhaps the unanswerable question is: Which one is most likely to meet the needs of the reasonably prudent homeowner?

Also: What’s the difference between a whole-house surge suppressor and a “line conditioner”?

7

I was recently researching transient voltage surge suppressors, and many sources recommended that they be listed under “UL 1449, second edition”.

See http://www.leviton.com/sections/prodinfo/surge/ul1449.htm

I believe line conditioners are more for things like undervoltage, overvoltage, and noise.

8

The secondary surge suppressor is the one most widely marketed in the electrical supply houses for a residential application.