A residential customer has requested surge suppression protection.
I'm thinking panel mount TVSS and TVSS receptacles at computers, etc. Is this overkill? How about Lightning arrestor (cheaper) at the panel and TVSS receptacle?
Any suggestions on best protection scheme per dollar spent would be appreciated.

In my experience, a TVSS at the outlet is not very useful, as the long path (romex ground or BX armor) back to earth ground has relatively high inductance. A combination of lightning arrester at the meter and TVSS at the panel (both with a heavy, low reactance path to earth ground) would be the way to go.

At individual outlets, RFI/EMI suppression is a good idea, both at sensitive electronic equipment, and devices likely to "dirty up" the powerline.

I used a unit from Cutler Hammer a year or so ago that mounted at the panel and also protected phone and cable. I dont remember any specs from it but it was a couple hundred dollars I believe.

A good Panel Protector TVSS is available from Leviton. Check into the 32000 and 42000 Series.

The NJWirenut is on the right track.

To properly protect everything in the house, you would need an arrestor at the service. This is a brute force device that does not clamp real close to the line voltage, but it can take a fairly strong hit. It can protect conductors & some appliances, but should not be relied upon to save your electronics.

At the point of use, a surge supressor receptacle should be installed. This will absorb the energy that gets past the service. The point of use device is not very robust, but will clamp much closer to the operating voltage.

The branch circuit wiring also attenuates some of the energy and it should be noted that most small spikes are generated within the building. Big time offenders being any motor load (about 20 in the average house) & refrigeration type loads seem to be prime offenders.

Also, don't forget to protect phone lines (the phone companies arrestor should not be relied on) and CATV lines and any other wire that goes to the outside world.

Of course, most of this is useless unless the grounding system is properly installed and all other systems are properly bonded to the service entrance.

Tom

[This message has been edited by Tom (edited 02-23-2002).]

[tiger trap] In that case, what's wrong with the plug-in-strip surge suppressor that's commonly used with P/C's[/tiger trap]??

Probably nothing wrong with the surge strip, but it is my understanding that the hard wired receptacle will have a higher suppression rating.

There are advantages to using a strip. Some of the premium ones come with a warranty that will pay anywhere from $10,000 to $25,000 for equipment replacement if anything gets past the strip if it is plugged into a properly grounded outlet. Also, some of the strips come with telephone jacks in them that will provide protection for the telephone line.

One word of caution one the phone protection, I'm not sure where the cut off is, but if the telephone protection involves too much capacitance (more than a couple of hundred picofarads?), your modem will run slower.

Tom

Thanks for all the input guys!

Would you consider the plug in strip a "temporary" extension cord?
And if so, would you have to "unplug it" once every 90 days? ??

I would suggest using good TVSS equipment at the main service [not just the simple MOV things!], discharge device[s] at the CATV and the Telco's MPOE [for POTS] for the "Bad Surges", then use local supression at the Equipment to complete the package.
Local TVSS would be a Quality TVSS Plug Strip for AC Power at the Equipment, plus quality TVSS for the POTS [Phone line] and / or CATV at the Equipment.

As suggested by another member, make sure these TVSS items for the phone and / or CATV system[s] do not end up interfering with the service it's self.
If you need some info on this, let me [or us] know.

As to local AC TVSS items, I kind of lean towards plug strips with quality functions [filters and TVSS]. This is so when the protection fails, it can be replaced easier and is more noticable. Also result in having [somewhat] ample receptacles for things right at the TVSS protection, rather than from another plug strip.

I do not use the "Combo Power / Telephone TVSS Strips". Instead, the POTS TVSS protection is a separate unit.

A few suggestions to check prior to getting any POTS TVSS items would be to:

<OL TYPE=1>

[*]Check the On-Hook DC Voltage over a period of time,

[*]Check for an Off-Hook AC and DC Voltage level - with dial tone, with no sound and with normal conversation,

[*]Verify the Loop Current's level.
</OL>

This can be plotted against levels when protection is connected, to verify proper and ample levels.

Scott SET

Just wondering if anybody has ever collected on the insurance for failed surge suppressors, from what I've heard its basically a joke trying to collect from them? Also I have no interest in this company but you might want to check out www.surgex.com. I have included a snip from their homepage below.


"Other surge suppressors rely on "sacrificial components," metal oxide varistors (MOVs) or gas discharge devices, that shunt or divert power surges from the hot line to the neutral or ground line. Sensitive digital equipment systems depend on a clean and uncontaminated ground.

SurgeX® power filters offer an all new, revolutionary Series Mode technology, which captures surge energy and slowly releases it onto the neutral line. Surge energy will not contaminate ground lines or wreak havoc with your system peripherals. With every surge above a modest level that hits your system, the MOVs in ordinary surge protectors degrade until they eventually fail. Unfortunately, it is impossible to tell when an MOV has become ineffective, leaving you exposed to potential equipment destruction."

Alright, then, Is it an extension cord or not???.
Maybe now that question can't be ignored.
I'm gonna edit this 'cause I sound to grumpy.
I'll do a new thread in Code Discussions

[This message has been edited by electure (edited 02-25-2002).]

Electure,

The surge strips are (I hope) "relocatable power taps" (XBYS). "This listing covers relocatable power taps rated 250 v, ac or less, 20 amp or less, which are intended for indoor use as relocatable multiple outlet extensions of a branch circuit to supply laboratory equipment, a home workshop, home movie lighting control, musical instrumentation, etc."

The "Etc" covers a lot of ground.

Tom