-=| 4 to 20mA Surge Protection |=-

I'm having the worst luck with surge protection for field devices. 2 level meters ruined by lightning. I have Phoenix Contact surge protection on 4-20, but it doesn't like it's doing the job. Does anybody other recommendation for other surge protection? I'm possible looking into trying Transtector surge supprestion.

If you take a direct hit from lightning all bets are off. I have had good luck with the Phoenix units. Lately I've been using some Allen Bradley blocks (1492-JD3PSSTP) that incorporate a removable fuse and a surge suppression diode connected to ground. Results aren't in yet for long time performance, but they look pretty good. We also use surge suppressor/filters onthe incoming 120 VAC line.

Note that if you don't have a good ground on your panel the surge suppressors won't work.

We almost exclusively use Transtector. I usually use the DRDC units for my loops. They are a sacrificial type arrestor, so I have had a few pop. HOWEVER! They have a 5-year UNCONDITIONAL warranty! I haven't yet had a Transtector unit pop that they have not replaced within a week, no questions asked. I also haven't yet, with the exception of one direct hit that basically demolished everything at the site, had a Transtector DRDC or DR120 arrestor let a surge through. Just my $.02

I have been using Citel. Never had a problem with them. I also like that you can remove the module, which disconnects the loop.

http://www.citelprotection.com/citel/DIN%20Rail_telco.htm

Jung,

If you are getting hit often by lightning, then some lightning protection may be needed. As Tom pointed out, for a direct hit there are no surge protectors that will prevent damage.

Lightning protection would not prevent strikes, but it would minimize the damage. There are 3 or 4 types of lightning protection systems. The cheapest, least effective is lightning rods connected to a grounding system. The most effective is overhead wires strung between poles, about 15 feet above the equipment to be protected. The wires are spaced so that a strike within 100 feet cannot reach the equipment (100' strike radius) without first encountering a grounded wire.