Power Surge

  • Thread starter Thread starter David LeBrun
  • Start date Start date
You might want to visit http://www.tomshardware.com/ and search for his
reviews on several power supplies. Antec, Enermax, and Zalman were all
good units. I tend towards the Antec PSUs (because they have more
reserve power over their rated power). If you get Antec's stealth
cases, like the Sonata, they use a modified PSU where the
thermistor-controlled rear fan is still there but the always-on
no-control bottom intake fan is removed (but the intake vent holes are
larger). The reduction of the always-on no-control fan makes the unit
quieter. I've heard the Zalmans are quiet, starting at 20 db at normal
temperatures and going up to 30 dB at high temperatures (which is still
a lot quieter than a lot of the 50 dB fans out there).

When I look at the testing rig that Tom setup to check power supplies, I
start to salivate and ponder what it would take to make one myself.
Unfortunately, he never publishes how he built his custom test gear. It
sure is a hell of a lot better test rig than those simple plug-in
testers that provide a minimal load. I still wonder what he uses to
measure such low sound levels. The sound meters that I can find at
retail stores or a Google search only go down to 30 dB and are pricey.
 
The black phone line block sound like an old protector that
was obsoleted by one that looks like this:
http://www.inwap.com/inwap/chez/Phoneline.jpg
This protector has long since been obsoleted by the
semiconductor protectors currently installed. Codes have
since changed. Phone company wire ends in a box, often
labeled NID, that is typically only 12 inches from where your
wire enters the house and outside building so that telco can
access this box. That NID would contain a surge protector, a
dedicated wire to earth ground, and would like interface boxes
in:
http://www.alarmsuperstore.com/bw/bw connectors.htm

Notice ground wire from bottom of each box. Consider having
the phone company upgrade your phone service to current
standards of the past decade plus.

With cable and satellite dish connected to (what sounds
like) a buried plated on other side of house, then they have
set house up for potential surge damage (a function also of
underlying geology). Since AC electric is not earthed to same
single point as cables, then surges have but another path to
damage household appliances.

Concept was demonstrated by Boy Scouts camping near trees.
Tree was struck by lightning. All boys sleeping sideways to
tree were unaffected. But two boys sleeping pointed to the
tree became victims. Electricity flowed down to earth on
tree. Then entered boy's feet, traveled through body, and
exited via head. Those two Boy Scouts had two earth grounds -
one at foot and other at head. Therefore they suffered
electrical shocks because body completed an electrical
circuit.

Your house can suffer same. Surge enters on AC electric
ground. Travels destructively through household appliances.
Then exits on cable or satellite dish ground. Appliances
connected to satellite dish and cable being at greatest risk
just like boys sleeping pointed towards tree.

One solution - a halo ground that encircles building and
connects to all earth grounds. Halo ground would be
equivalent to boys sleeping sideways to tree. Demonstrated in
this figure:
http://www.cinergy.com/surge/ttip08.htm

Ground wire to water pipe was once considered earth ground.
Today that wire is insufficient; simply to remove electricity
from pipes for human safety. Post 1990 code now calls for a
second earth ground using a dedicated ground rod (or
equivalent). This typically becomes the single point ground
to which all other utilities are earthed.

Since your water pipe ground wire is probably the only earth
ground connection, then wire should terminate with no pipe
joints between where wire connects and where pipe contacts
earth. Especially important - water meter is not between that
ground wire connection and earth.

Should you decide to have any electrical work done
(including installing a 'whole house' protector), then have
that earth ground rod installed with a short connection to
breaker box. Safety ground must exist to cold water pipe as
you have observed. But post 1990 code calls for another
dedicated earth ground. Surge protection requires this earth
ground be connected by less than 10 foot wire without sharp
bends, etc. Wire from breaker box to earth ground rod should
also not be bundled with other wires.

These requirement are beyond what code demands because that
earth ground wire is also doing surge protection. IOW if
ground wire to GEC can be run more direct and shorter through
cinder block wall (rather than up through wood joists and back
down to earth), then do so - only to make surge protection
more effective and to keep that ground wire away from other
non-earthing wires.

Only after this central earth ground is established should
phone company upgrade their interface and earth to that same
ground rod. Your home currently does not (sound like it) have
the current technology protectors that provide effective surge
protection.

Of course, how frequent are lightning strikes in your
neighborhood. Just another consideration when evaluating what
need be accomplished.

Other standards have been upgraded since your electric was
installed. For example, a ground wire must bypass water
meter. Some jurisdictions require that gas line be connected
to breaker box safety ground (check with gas company). Jumper
between hot and cold water pipes at water heater may be
required. But these are upgrades only required for human
safety reasons.

However a major problem that may now be expensive to fix are
those cable and satellite dish wires entering on far side of
building and not to the important single point earth ground.

One additional check. The pole with transformer that serves
your home- is that pole's earth ground intact? Just another
important earth ground for your household surge protection
system - that must exist (and for free).
 
Hey...I had one of those Deer PSUs...it was in my first 386 and was
still kicking around until a few months ago when I trashed it because
my parts cabinet was way too full.

I forgot all about RF problems. I can't recall having any problems
with that though. I'm not sure if I have the specs for the AOpen unit
or not...but could probably find one on the net if it was actually
made by AOpen. I agree though that specs are important whether or not
they are fully understood...I would say that most don't even
understand the sticker usually found on the shell.

Thanx for the link...I'll be sure to check it out.

Dave.
 
I just recently set a Sonata cased system up. The PSU also only has 1
internal fan where the unmodded version has 2...for the sake of quiet
running. A nice case to use in the living room next to the TV/Stereo.
The fan is extremely quiet because it spins at low rpm...it actually
set the alarm off in the BIOS when I started working on that system.

I will definitely check Toms out...haven't been there in a while.

Dave.
 
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