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#7798 02/22/02 03:11 PM
Joined: Mar 2001
Posts: 2,056
R
Redsy Offline OP
Member
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.

#7799 02/22/02 06:15 PM
Joined: Sep 2001
Posts: 806
N
Member
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.

#7800 02/22/02 06:37 PM
Joined: Jan 2002
Posts: 1,457
E
Member
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.

#7801 02/23/02 09:52 AM
Joined: Dec 2000
Posts: 4,294
Member
A good Panel Protector TVSS is available from Leviton. Check into the 32000 and 42000 Series.

#7802 02/23/02 01:17 PM
Joined: Jan 2001
Posts: 1,044
Tom Offline
Member
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).]


Few things are harder to put up with than the annoyance of a good example.
#7803 02/23/02 04:23 PM
Joined: Dec 2000
Posts: 4,294
Member
[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]??

#7804 02/23/02 07:34 PM
Joined: Jan 2001
Posts: 1,044
Tom Offline
Member
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


Few things are harder to put up with than the annoyance of a good example.
#7805 02/23/02 09:52 PM
Joined: Mar 2001
Posts: 2,056
R
Redsy Offline OP
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Thanks for all the input guys!

#7806 02/24/02 02:38 PM
Joined: Dec 2000
Posts: 4,294
Member
Would you consider the plug in strip a "temporary" extension cord?
And if so, would you have to "unplug it" once every 90 days? [Linked Image]??

#7807 02/24/02 08:13 PM
Joined: Oct 2000
Posts: 2,723
Likes: 1
Broom Pusher and
Member
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


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
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