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

ECN Shout Chat
Top Posters(30 Days)
Admin 19
Recent Posts
fuse rejectors
by NORCAL. 03/29/17 01:44 AM
Old decora style outlets
by NORCAL. 03/29/17 01:41 AM
NFPA stuff
by gfretwell. 03/28/17 08:08 PM
Anyone hiring inspectors?
by HotLine1. 03/27/17 08:03 AM
ESA Arc flash course
by TheShockDoctors. 03/24/17 10:15 AM
New in the Gallery:
SE cable question
Popular Topics(Views)
231,713 Are you busy
166,612 Re: Forum
160,777 Need opinion
Who's Online Now
0 registered members (), 56 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#7798 - 02/22/02 03:11 PM Suppression Suggestion  
Redsy  Offline
Member
Joined: Mar 2001
Posts: 2,056
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.


Work Gear for Electricians and the Trades

#7799 - 02/22/02 06:15 PM Re: Suppression Suggestion  
NJwirenut  Offline
Member
Joined: Sep 2001
Posts: 806
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.


#7800 - 02/22/02 06:37 PM Re: Suppression Suggestion  
Electricmanscott  Offline
Member
Joined: Jan 2002
Posts: 1,457
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.


#7801 - 02/23/02 09:52 AM Re: Suppression Suggestion  
electure  Offline


Member
Joined: Dec 2000
Posts: 4,259
Fullerton, CA USA
A good Panel Protector TVSS is available from Leviton. Check into the 32000 and 42000 Series.


#7802 - 02/23/02 01:17 PM Re: Suppression Suggestion  
Tom  Offline
Member
Joined: Jan 2001
Posts: 1,044
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.

#7803 - 02/23/02 04:23 PM Re: Suppression Suggestion  
electure  Offline


Member
Joined: Dec 2000
Posts: 4,259
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]??


#7804 - 02/23/02 07:34 PM Re: Suppression Suggestion  
Tom  Offline
Member
Joined: Jan 2001
Posts: 1,044
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.

#7805 - 02/23/02 09:52 PM Re: Suppression Suggestion  
Redsy  Offline
Member
Joined: Mar 2001
Posts: 2,056
Bucks County PA
Thanks for all the input guys!


#7806 - 02/24/02 02:38 PM Re: Suppression Suggestion  
electure  Offline


Member
Joined: Dec 2000
Posts: 4,259
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? [Linked Image]??


#7807 - 02/24/02 08:13 PM Re: Suppression Suggestion  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,707
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!

Page 1 of 2 1 2

Member Spotlight
dougwells
dougwells
kamloops BC Canada
Posts: 1,137
Joined: May 2003
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.015s Queries: 15 (0.003s) Memory: 0.8185 MB (Peak: 0.9946 MB) Zlib enabled. Server Time: 2017-03-29 09:18:40 UTC