Rain8Net and Thunder Storms

[gbirk]

All my irrigation control wire terminates in an OnQ Panel mounted in a closet. I have two Rain8Net irrigation controls mounted in this panel. From there, I have ~ 30 feet of CAT5 cable that runs to a serial port on my automation PC. It seems like after every major thunder storm, the serial port that the Rain8Net is connected to will die.

This past Sat., I was getting ready to go to Tokyo again. I just spent the day setting up the Homeseer Insteon Plug-in (worked great and the lights were all setup to turn on and off while I’m away). It started to rain and some lightning hit near the house. I went to check on the PC and smelt fried electrical parts. My 40 day old Belkin UPS would not start up and the PC was dead, will not boot. I also unplugged the two Rain8Net units and tried to test them with my laptop using Rain8Master Config. I was unable to read eithe unit’s address or reprogram the units.

I bought the units last fall. I sent one unit back to WGL a few months ago for a similar problem. They were great to work with, repaired the unit and I like the product. However, I can not keep replacing serial cards and now a UPS / PC after ever thunderstorm.

What can I do to prevent this? I have it wired just like WGL shows on their web site. Do I need some sort of serial surge protector and if so, where can I get one? What can I do to minimize this from happening again?

 

[BraveSirRobbin]

http://www.tmanufacturing.com/surgeprotection.html

Serial lines are a problem with electrical storms. I had my PC's behind a UPS but my Caddx Security system's serial interface got fried. There is a lot of wire just hanging out there between your serial peripherals and the computer that can pickup this high voltage and no UPS will protect that.

 

[gbirk]

Thank you - looks just like what I need

 

[markthomas]

Wouldn't opto-isolators work as well?

 

[BraveSirRobbin]

Wouldn't opto-isolators work as well?

Link?

 

[DavidL]

http://www.bb-elec.com/product_family.asp?...&TrailType=Main

 

[huggy59]

I'd go with both. Put the optical isolator inline and put the surge suppressor on the PC serial port.

 

[JeffVolp]

There are really two types of problems with lightning. First, there is the induced voltage from a nearby strike. Things that other people have discussed like surge suppressors and opto-isolators will help. You could add surge suppressors on the AC lines running out to the irrigation valves. Even better would be to use the Rain8 to drive opto-isolated relays to actually control the valves. Opto-isolator relays are cheap in the surplus market, and can be considered expendable.

The other problem with lightning is a direct strike. If it gets directly onto a conductor, all bets are off. Nothing can really protect against the amount of energy in a direct strike. Opto-isolation means nothing. Hopefully, most of that energy will find a direct route to ground. But it can leave behind a path of destruction in its wake.

I do have some experience with both types of strikes.

Jeff

 

[JeffVolp]

We had a nasty storm come through yesterday, and SkyWest Airlines found out what lightning can do:

http://www.thespectrum.com/apps/pbcs.dll/a...EWS01/610150311

We had a couple of strikes within 1000 feet (one second from flash to crash), but nothing real close.

Jeff

 

[electron]

As someone who just got forced to replace all HA equipment because of a direct hit (plenty of surge protectors and industrial UPS units inplace), I can attest that you can't stop the 2nd type Jeff mentioned. I guess that's why you have home owners insurance, just make sure that if you run a business from home , or work from home, that you talk to your insurance agent,or they might not cover your installion at all.

I did invest in a few more specialized surge protectors, but that's only to handle the nearby hits. Oh yea, as for lightning never striking the same location twice, it does