Subscriber Discussion

Coax Vs Cat 5e In Lightning Prone Areas

jo
jason oneal
•Jan 26, 2016

Is there any advantage at all to use coax vs cat 5e in an area that has "allegedly" been hit several times before by lightning? I am dealing with an IT Director for a health facility who has twice before installed his own IP cameras. When both systems went down he blamed lightning. Others involved are skeptical that lightning was the problem and no one investigated to be sure. The only proof he has is the fact that the system stopped working during a storm and he has an RJ45 blacked out. (I have seen water get into a cable through a pin prick in the jacket and fill the cable. Then the water made it's way to the POE port and shorted it out.) The IT Director is pushing the Board to not consider an IP option due to this. He claims it will not work even with measures taken to decrease the risk of lightning damage. He also claims to have installed several cameras in the area on coax with no issues. I believe it is probably due to a faulty install or maybe even the IP cameras were not damaged at all but he assumed they were. I am pushing an IP system here due to the size of the complex, number of buildings, and options they are looking for.

So, is coax less susceptible to lightning than Cat 5e?

UM
Undisclosed Manufacturer #1
•Jan 26, 2016
I always thought copper was copper was copper, but I have been wrong before...
(2)
U
Undisclosed #2
•Jan 26, 2016
IPVMU Certified
In reply to Undisclosed Manufacturer #1

*Warning - Speculation*

Agree copper is copper, but more copper is less resistance and maybe more attractive to lightning? Probably no practical concern in any real world scenario...

Don't know the answer but wondering which has more copper/ft, cat or coax?

cat 5 STP vs rg-59

cat 6 STP vs rg-6

Avatar
Brian Rhodes
•Jan 26, 2016
IPVMU Certified

Running any cable outdoors requires protection against impacts like lightning, UV, rodents, other EMI sources, and weather. Coax by nature has a shield, but STP cable for outdoor cameras is a routine requirement. See: STP vs UTP for Surveillance

On other words, there is no reason IP cameras cannot be run outside.

U
Undisclosed #2
•Jan 26, 2016
IPVMU Certified

I have seen water get into a cable through a pin prick in the jacket and fill the cable. Then the water made it's way to the POE port and shorted it out.

FWIW, this can still be due to lightning. A lightning strike that doesn't take out the cable, (due to proper bonding/grounding), can still cause conductive pinholes at the site of where the surge enters. These can let moisture in and eventually cause failure. IMHO, gel-filled cables would deter this.

Certainly UTP would be more susceptible to lightning damage than coax. It's basically 8 unprotected and ungrounded conductors so...

On the other hand, as Brian points out, STP is usually run outdoors for this reason, among others. Assuming that the shielding is carried thru all insertion points and grounded properly, I don't see why it would be more susceptible than coax.

Net/Net:

If you and the IT Director are arguing about existing outdoor cable and its UTP; then you may want to let it drop. If the cable is STP or you are talking about future cable, you should stand your ground.

(1)
jo
jason oneal
•Jan 26, 2016

The existing cabling is STP. I will be running new cable anyway for a couple of reasons. 1.) their uneducated choice of camera locations does not cover what the board wants 2.) with so many claims of lightning being the issue, I want to start with a fresh install.

With every solution I bring up for surge protection, the IT Dir continues to play devil's advocate. He says "Done that, didn't work, good luck with that." I really get the feeling this is personal. I could imagine being in his shoes... spent the money and tried twice but failed and now a non-college degree security integrator thinks he can make it happen. I just know that I have installed hundreds of cameras outdoors in the same area and not one lightning strike causing mass failure. Not to mention two strikes. Wondering if maybe the facility has other electrical issues that cause it to be more affected by nearby strikes? Or maybe the circuit the original switch was on took a hit that caused damage and he used the same circuit the second time without checking it?

My proposal will definitely include any and all surge protection devices and techniques I can come up with. It seems that the only selling point I need to push is surge protection and not camera system bells and whistles.

U
Undisclosed #2
•Jan 26, 2016
IPVMU Certified
In reply to jason oneal

Since you are running new cable anyway, have you considered using Fiber between buildings?

It lets the IT director save face, and is worth considering in a lightning prone area. :)

jo
jason oneal
•Jan 27, 2016
In reply to Undisclosed #2

Yep, I will be quoting two options: 1.) fiber 2.) all Cat 5 with lots of surge protection. They say that switches is all that has gone out. Personally, I would rather have the Cat 5 properly installed and just eat a few switches here and there. We will see which route they find most appealing.

UM
Undisclosed Manufacturer #1
•Jan 28, 2016
What are your "go to" products for surge suppression/protection? I'm not here to solicit my products (unless you'd like my $0.02); I would just like to know what people are using and their experiences... Disclosure: I rep some surge suppression products.

NOTICE: This comment has been moved to its own discussion: Surge & Lightning Suppression Recommendations Needed

jo
jason oneal
•Jan 28, 2016
In reply to Undisclosed Manufacturer #1

I've used these from L-com. I'm open to suggestions. This will be a pretty large job for me and obviously will be let down if there is a large scale malfunction due to lightning.

New discussion

Ask questions and get answers to your physical security questions from IPVM team members and fellow subscribers.

Newest discussions