DIYbanter - View Single Post - Whole house surge suppressor -- Tytewadd??

Pop`

wrote:
We're moving into a house that has older two-wire ungrounded wiring.
Short of the expense of rewiring the entire house, I'd like to make it
as safe as possible for people and equipment. I've already put in
GFCI outlets in bathrooms, kitchen, garage, outdoor locations. So
from a people safety perspective I think that's about as good as we
can do, and grounding would not improve that situation.

Now for equipment, I'm thinking about a panel-based whole house surge
suppressor, since the lack of grounding will defeat any point-of-use
surge suppressors. There seem to be quite a few units available with
similar specs: clamping voltages in the 400-500V range, energy
dissipation on the order of 1000 joules, maximum current 50,000 amps,
5 ns response. One example is the Intermatic 1G1240R. These seem to
generally be described as sufficient for protecting appliances but the
vendors still recommend point-of-use surge suppressors for electronic
equipment.

There is also a product sold by Tytewadd, which clamps at 130V,
maximum current 10,000 amps, and 1.5 ns response. It is specifically
advertised as protection for "sensitive equipment". But... it has a
total energy dissipation of only 70 joules, far far less than the
previous class of units.

Does anyone have experience with the Tytewadd devices? They're not
that cheap -- $150. I'm in a generally low-lightning-risk location
(Northern California, bay area) so maybe this kind of moderate
protection is sufficient. But 70 joules is less than the specs on a
rinky dink power strip. Should I save my money, ask an electrician to
rewire a couple outlets in key locations, and stick with power strip
surge suppressors?

-- Dave

130V ac is too low a voltage for a clamp; line voltages can go to 132Vac for
short periods of time and be "in spec". Are you sure you read that right?
Sounds more like someting for a lab environ or such. Anyway, since you're
talking suppressors and not conditioners, that's too low a voltage rating
for everyday use 24/7; you'll spend all your time wondering why it's
alerting.

Joules are the important number; the higher the better. 70 joules is next
to useless for a whole-house arrangement. I'm surprised the numbers don't
go higher than 1,000 too, but haven't fiddled in that market for some time.
Joules are a measure of the total power it can consume while "protecting"
the house, so get as high as you can.

Any timng in the nanoseconds range should be OK. You'll probably find that
as the joules go up, the nanoseconds time gets longer, too, and that's
normal within reason. If there is mention of zero-crossing design too,
that's another good feature.

Amps and/or Volts alone aren't very accurate measures of the quality of a
suppressor; so pay attention to the joules numbers the most.

And just a short reminder: NOTHING can protect you against a nearby
lightning hit, so watch out for too much marketing hype in that vein. That
said however, lightning is often the cause of substantial spikes and surges
on the power lines; the transofrmer out on the pole helps smooth thouse out
a lot, but if it's a close enough hit, nothing will "protect" against it.

That's great and logical actions for the GFCI work you did. Sounds like
it's to code and you caught the important places to have them.

An EXCEPTION for the 2-wire outlets is going to be for your computer and
other electronic equipment around the house. IFF a product is sold with a
3-wire cord, then the 3-wires are necessary for a myriad of reasons ranging
from UL type safety requirements to FCC RF requirements.
You might want to give some thought to providing the 3rd wire (earth
ground) for the outlets where you connect your computer, TV, Stereo, things
like that. Computers and their peripherals in particular depend on the
ground connection for a lot of things.

This one's an important safety consideration: All 2-wire outlets must
have the polarity type openings, two different sizes in other words; shorter
one is hot, longer one is neutral. And of course the plugs that go in them
must conform also, in case you have any equipment where a plug or cord has
been replaced on it.
Not all plugs have the two different sized blades on them; they may be
what's called Class 2 devices; in these cases it doesn't matter which way
they're plugged in; there is no polarity to worry about.
IFF there is a third wire though, there really does need to be a ground
in the outlet for that third wire to connect to.

HTH,
Pop`