The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Page 1 of 2 1 2 >
Topic Options
Rate This Topic
#7798 - 02/22/02 11:11 AM Suppression Suggestion
Redsy Offline
Member
Registered: 03/28/01
Posts: 2138
Loc: Bucks County PA
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.
Top
Work Gear for Electricians and the Trades
#7799 - 02/22/02 02:15 PM Re: Suppression Suggestion
NJwirenut Offline
Member
Registered: 09/15/01
Posts: 816
Loc: Bergen County, NJ
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.
Top
#7800 - 02/22/02 02:37 PM Re: Suppression Suggestion
Electricmanscott Offline
Member
Registered: 01/12/02
Posts: 1478
Loc: Holden, MA USA
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.
Top
#7801 - 02/23/02 05:52 AM Re: Suppression Suggestion
electure Offline


Member
Registered: 12/24/00
Posts: 4229
Loc: Fullerton, CA USA
A good Panel Protector TVSS is available from Leviton. Check into the 32000 and 42000 Series.
Top
#7802 - 02/23/02 09:17 AM Re: Suppression Suggestion
Tom Offline
Member
Registered: 01/01/01
Posts: 1069
Loc: Shinnston, WV USA
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.
Top
#7803 - 02/23/02 12:23 PM Re: Suppression Suggestion
electure Offline


Member
Registered: 12/24/00
Posts: 4229
Loc: Fullerton, CA USA
[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]??
Top
#7804 - 02/23/02 03:34 PM Re: Suppression Suggestion
Tom Offline
Member
Registered: 01/01/01
Posts: 1069
Loc: Shinnston, WV USA
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.
Top
#7805 - 02/23/02 05:52 PM Re: Suppression Suggestion
Redsy Offline
Member
Registered: 03/28/01
Posts: 2138
Loc: Bucks County PA
Thanks for all the input guys!
Top
#7806 - 02/24/02 10:38 AM Re: Suppression Suggestion
electure Offline


Member
Registered: 12/24/00
Posts: 4229
Loc: Fullerton, CA USA
Would you consider the plug in strip a "temporary" extension cord?
And if so, would you have to "unplug it" once every 90 days? ??
Top
#7807 - 02/24/02 04:13 PM Re: Suppression Suggestion
Scott35 Offline

Broom Pusher and
Member
Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
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!
Top
Page 1 of 2 1 2 >

Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box

Recent Posts
Members: Non-Members: Did you know?
by Admin
01/22/17 02:34 PM
Safety at heights?
by HotLine1
01/21/17 08:51 PM
International Wire Colour Codes
by Texas_Ranger
01/21/17 03:29 PM
Looking for older post
by Texas_Ranger
01/21/17 03:22 PM
Last time to chat here
by Trumpy
01/20/17 11:41 PM

Who's Online
3 registered (Admin, Texas_Ranger, HotLine1), 88 Guests and 11 Spiders online.
Key: Admin, Global Mod, Mod
New in the Gallery:
Desk-mounted "power-board"
Top Posters
gfretwell 9066
Trumpy 8560
pauluk 7693
HotLine1 6833
sparky 5545
Member Spotlight
Member Since: 03/29/08
Posts: 144

ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals