Re: From OP: Re: Intermatic Whole House Surge Protector ?

w_tom wrote:
On Apr 18, 2:07 pm, "Robert11" <rgs...@xxxxxxxxx> wrote:
Thanks for help and info.
Appreciate it.

You are right; the 4870 model doesn't seem to be listed anymore.

Probably replaced by something newer.
Will give them a call Monday and ask.

The best information on surges and surge protection I have seen is at:
http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf
- "How to protect your house and its contents from lightning: IEEE guide for surge protection of equipment connected to AC power and communication circuits" published by the IEEE in 2005 (the IEEE is the dominant organization of electrical and electronic engineers in the US).
And also:
http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf
- "NIST recommended practice guide: Surges Happen!: how to protect the appliances in your home" published by the US National Institute of Standards and Technology in 2001

The IEEE guide is aimed at those with some technical background. The NIST guide is aimed at the unwashed masses.


Therefore the Intermatic will only be as effective as the earth
ground - as others have noted. That means a breaker box ground wire
should not go up over the foundation and down to earth. Instead, that
ground wire should be through the foundation and down to earth. Every
wire foot shorter means better surge protection. No sharp bends. No
splices. And all grounds (telephone, cable) make a 'less than 10
foot' connection to this earthing electrode.

Even with a very good resistance to earth of 10 ohms and a fairly strong earth current of 1,000A the power system ground rises to 10,000V above 'absolute' earth potential. Protection has more to do with keeping ground references together - short 'ground' wires from signal entrance protectors to the 'ground' at the power service. The NIST surge guru, and author of the NIST guide, has written "the impedance of the grounding system to `true earth' is far less important than the integrity of the bonding of the various parts of the grounding system."

The priority is not short connection to the same earthing electrode. The priority is short connection from signal entry protectors to the 'ground' at the power service.

Cable TV
needs no protector since it gets earthed only with a wire.

"Needs no protector"? The IEEE guide says "there is no requirement to limit the voltage developed between the core and the sheath. .... The only voltage limit is the breakdown of the F connectors, typically ~2–4 kV." And "there is obviously the possibility of damage to TV tuners and cable modems from the very high voltages that can be developed, especially from nearby lightning." (A plug-in suppressor will limit the voltage from core to shield.)

What makes any
protector effective? Its connection to earth.

For plug-in suppressors, the IEEE guide explains (starting pdf page 40) they work primarily by CLAMPING the voltage on all wires (signal and power) to the common ground at the suppressor. Plug-in suppressors do not work primarily by earthing (or stopping or absorbing). The guide explains earthing occurs elsewhere.


Same protector that makes lightning surges irrelevant also makes
irrelevant the 'inside the house' surge. If household appliances are
creating surges, then you are trooping daily to hardware stores for
new dimmer switches, clock radios, and bathroom GFCIs.

According to NIST guide, US insurance information indicates equipment most frequently damaged by lightning is
computers with a modem connection
TVs, VCRs and similar equipment (presumably with cable TV connections).
All can be damaged by high voltages between power and signal wires.


Install a 'whole house' protector so that significant protection
already inside all appliances is not overwhelmed.

Service panel suppressors are a real good idea.

What does the NIST guide say?
"Q - Will a surge protector installed at the service entrance be sufficient for the whole house?
A - There are two answers to than question: Yes for one-link appliances [electronic equipment], No for two-link appliances [equipment connected to power AND phone or cable or....]. Since most homes today have some kind of two-link appliances, the prudent answer to the question would be NO - but that does not mean that a surge protector installed at the service entrance is useless."

A service panel suppressor by itself does not guarantee there will not be damaging voltage between power and signal wires.

--
bud--
.

Relevant Pages

  • Re: Fiber-optic isolator?
    ... If using a protector, such as Transtector, at the entrance to each building, the ground connection should connect with a *short* wire to the earthing wire at the power service. ... Plug-in suppressors work primarily by clamping the voltage on all wires to the common ground at the suppressor, ...
    (alt.internet.wireless)
  • Re: Leakage current in SF 280R
    ... My intention was to keep track of power consumption from this server, ... is the reported leakage current. ... However, yesterday the surge protector tripped, blaming the ... and which depends on the ground connection through ...
    (comp.sys.sun.hardware)
  • Re: Power Conditioners?
    ... If it was my house, I would then run the phone wire to the vicinity of the power service, install a second protector there, and distribute the phone wires from that point. ... Cable and Primary Protector Grounding ...
    (rec.music.classical.recordings)
  • Re: 2008 Avalon lighter/accessory wires or power tap for radar detector
    ... The lighter/accessory power tap would be perfect but I can't get to ... intermittent connection could result in damage. ... I never said crimp connectors were unreliable, ... splice into a wire using crimps, and cover them with heat shrink tubing. ...
    (alt.autos.toyota)
  • Re: Surge protectors in series
    ... "All Belkin Surge Protectors must be plugged directly into a properly wired AC power line ... ... Years ago, I was impressed with the argument at the website of an English manufacturer that if your phone ground electrode wasn't bonded to your power ground electrode, it was safer not to plug your phone line into your point-of-use protector. ... For good protection, not only must the phone entry protector connect to the "ground" at the power system, the connection must be with a short wire to prevent high voltage between power and phone lines. ...
    (alt.home.repair)