Topic: Surge Suppression

[aeroclown]

Hi All, I am looking into getting a Boltek Detector package. After some research it appears the the antenna link uses a Cat5 style data cable. Since this is a high point installation and it is an antenna, I suspect it will be susceptible to Lightning strikes. My Weather Station, Vp2, is wireless so there is a stop gap there. I wanted to see what kind of input or suggestions there might be for inline suppression of surges of the data link going into the house from the actual detection antenna.

[George Richardson]

Aeroclown,

In my business, over half of the damaged equipment I replace is Lightning damage so I am quite anal about protection. That being said, I really don't see much you can do. I found a Cat5 in line arrestor for about $50. but my experience with that type of product is not very encouraging. I already have a PTZ camera mounted high on the outside of my home not more than 5' to 10' lower in elevation than my Boltek antenna will be. Lightning is just looking for the easiest path to ground and all I can do is hope there are better paths to ground in my area. I would think Boltek has not had MUCH problem in this area or they would provide that $50. arrestor in their product line. They do seem to lean toward indoor (attic) installations but lightning doesn't respect roof lines if it sees a path to ground.

FWIW

George

[aeroclown]

Good enough for me.

Thanks George.

I'll forego the arrestor then. Now if only ambient would get Nexstorm back in stock I would be ready to buy.

[racenet]

This has been cover many times, on different forums, for many years. The short answer is, no, you can not add surge protection in-line with the boltek antenna.



Bob

[westom]

I'll forego the arrestor then.

Routine is to have direct strikes and no damage.   Routine is to have damage when one foolishly thinks in-line (series) protection will somehow block or absorb surges.

  For example, to protect that camera, don't stop lightning.  Intercept it - divert it - on a more conductive path to earth.  Surges seek earth ground.  Damage means a path to earth was through electronics.  Camera protection is a Franklin lightning rod above the camera and connected better to protection - earth ground.  A lightning rod does not protect the camera.  The lightning rod is only as effective as what provides protetion: earth ground.  A direct lightning strike that need not find earth through the camera is not damaged.

  Same applies to your Cat 5 wire.  Routine is to earth every wire in that cable before it enters the building.  A connection from each wire, through protector, to earth ground must be short ('ie less than 10 feet'), no sharp bends, no splices, a single point earth ground, and ground wires separated from all other ground wires.

  Routine is to have direct lightning strikes and no damage even to the protector.  But that means properly installing and connection to what provides surge protection. Not a magic box.  A single point earth ground.  A protector is only as effective as its earth ground.  The protector that will somehow stop or absorb surges is a scam.

[aeroclown]

http://electronics.howstuffworks.com/surge-protector.htm

Please have a good read on what a surge suppressor IS and what it's purpose is. Both suppressors and arresters require grounding or at least good ones usually do. So that magic box you speak of does do a job and it does ground a wire at least good ones do. Those that don't are obviously not designed for protection for a direct lightning strike. They are made to arrest moderate voltage variation to sensitive equipment not arrest a 20kw strike. My main interest is to protect the equipment from static discharge or variance in POE. If this house gets a direct hit, it will be nothing short of a ball of fire, because there are no common grounds in the house.

Personally I can't afford to re-wire my home to have a continuous earth ground. The boxes are to old and it would cost a fortune to have everything re-wired. Earth ground, yes are code today, but not everyone lives in a house built to today's code. The room where my computer equipment is, may be the only potion of the house that has an earth ground, because I drilled a hole in the wall and ran a cable out to a 10ft spike on the side of the house.

[Bluthunder2k]

This has been cover many times, on different forums, for many years. The short answer is, no, you can not add surge protection in-line with the boltek antenna.

Actually I found a commercial grade supressor that works fine on it.  It's made by Polyphaser and is one of their NX series units.

Talked to Boltek about it and the agreed with the specs it would work fine, and it has for 3 years now.

[dalecoy]

This has been cover many times, on different forums, for many years. The short answer is, no, you can not add surge protection in-line with the boltek antenna.

Actually I found a commercial grade supressor that works fine on it.  It's made by Polyphaser and is one of their NX series units.

Talked to Boltek about it and the agreed with the specs it would work fine, and it has for 3 years now.

As long as the surge doesn't exceed (depending on what model you got): "Surge current rating of this device is 300A, 10/1000us per Bellcore 1089 and 3kA, 8x20us per IEC 61000-4-5".

Which would be OK for surges induced by a NEARBY lightning strike.  But not for a direct hit.

[Bluthunder2k]

This has been cover many times, on different forums, for many years. The short answer is, no, you can not add surge protection in-line with the boltek antenna.

Actually I found a commercial grade supressor that works fine on it.  It's made by Polyphaser and is one of their NX series units.

Talked to Boltek about it and the agreed with the specs it would work fine, and it has for 3 years now.

As long as the surge doesn't exceed (depending on what model you got): "Surge current rating of this device is 300A, 10/1000us per Bellcore 1089 and 3kA, 8x20us per IEC 61000-4-5".

Which would be OK for surges induced by a NEARBY lightning strike.  But not for a direct hit.

At 300amps, the conductors of cat5 generally melts down from the strike.      In working with Motorola Canopy gear and Othrogon stuff thru the years, sites I have seen hit with these suppressors will have a section of cat5 several feet long totally missing from a direct strike, and usually the suppressor is damaged, but the gear inside the building 9 out of 10 times is still fine.  I've got photos of the damage these units have protected against somewhere, that's the reason I started using them, they actually work.  Another key is to put decoupling loops in the cat5 before it enters the building, lightning does not like going back uphill.

If I am really wanting to protect the CAT5, I use a Transtector model rated considerably higher and I use double shielded cat5 with the cat5 grounded every 100ft to the tower (better than R56 grounding specs), but those are on very tall structures where it's not a matter of "if" it'll get hit, but how often a year, like where I have my 70ft tall tower cam, and I need it to last, no matter.  That tower's been pegged three times since I put up the camera and it's still humming along.

No matter what suppressor you use, a single point of grounding and a well balanced under 5 ohm ground is key to survivability.  In my experience, ground potential rise and EMP is what causes the LION share of damage, not direct strikes.  (and i'm a 20 year broadcast engineer)

[dalecoy]

Thanks for the extended description.  I found it educational - and real-life experience from professionals is always valuable.

My experience is only with amateur radio and some small amount of commercial service.  I've seen my share of fragmented antennas, melted coax, etc., but obviously not as much as you have.

Of course, the Polyphaser units you're using are in the $100-and-up class. 

No matter what suppressor you use, a single point of grounding and a well balanced under 5 ohm ground is key to survivability.  In my experience, ground potential rise and EMP is what causes the LION share of damage, not direct strikes.  (and i'm a 20 year broadcast engineer)

Absolutely agreed.  And there's not much that the average person can do about ground potential rise.   

[port1]

I've read a bunch about those polyphasers, and installed some on security PTZ cameras, and no more blown equipment.
They're excellent, and I would recommend them, especially for expensive equipment.