lightning protection

Hello folks,

I have read several posts about lightning protection. I have read conflicting opinions on the 300ss from Motorola. Mainly, should I use these for the APs or not? If not, what other device is recommended? I know a direct hit will cause damage regardless.

Also, need to know about protection for the CMM. Is there a decent power bar that works for outdoor equipment?

Thank you.

I just found this in a previous post:

Why are you folks not using the Transtector surge-suppressors that Motorola is distributing FOR Canopy AP’s & CMM’s?

Motorola p/n: RRDN4543A = NEMA Enclosure/Chassis with 1 POE & 1 GPS card (covers 1 AP, has space for 8 more POE cards & 8 more GPS cards). List $400.00

Motorola p/n: RRDN4561 1 POE card (covers 1 AP, installs into RRDN4543A chassis) List $125.00

Motorola p/n: RRDN4544A 1 GPS card (covers 1 AP, installs into RRDN4543A Chassis) List $125.00

Obviously, if you are using CMMmicro then you don’t need to use the GPS cards, just the POE cards.

We are a Motorola dealer for Canopy and these units have been recommended for install since day 1 of Canopy’s existence (these units are actually a 2nd generation, prior there were 2 chassis’s from Transtector, each at about $500–1 for POE & 1 for GPS and each had a full complement of 8 ports covered). I have NEVER seen any recommendation that you install a 300SS for an AP.

If anybody has any problems finding these units through their distribution, I’d be happy to discuss a low fixed-%-above-cost arrangement to supply them.

Keir Johnson
Houston Communications Inc.
281-491-1616 Office

Is ANYONE using this rig? Results if so?

thanks again.

One more thing - is there ANY device that offers a guarantee or warranty against lightning/power surge damage to Canopy gear?

thanks again.

All AP and BH sites:

Newer style PoE protection we are using:

Old style PoE protection:

GPS protection:

Polyphaser GPS protectors for the actual GPS antenna: … R50LNZ%2b6

Upon installation of our first cluster of AP’s, we initially installed the 300ss’s at the top of the tower and and the bottom(one on each end of each Cat 5 cable).

To our dismay, we could not keep a link or ping going to all the AP’s.
We contaced MOTO support and learned that MOTO does not reccomend using the 300ss’s on AP installations. So, we took them all out and bingo the link problem went away.

Four days later we took a near lightning hit at the tower. All six AP’s and CMM were destroyed.

After replacing the equipment I went back with the 300ss’s on each end and the link problem returned.

We discovered that hard setting the speed on each AP to 10Mbs instead of 100Mbs took away the link problem.

The equipment, being 900Mhz does not need more than 10Mbs anyway due to the limits of the 900 radio bandwidth. So we were OK with 10Mbs.

This was a year ago and we have had no problems with lightning or dropping packets since, even with two 300ss’s on each AP, with over 200’ of Cat 5 running up the tower.

It appears that the 300ss’s introduce enough resistance to the Cat5 cable that the old 100 meter maximum length does not apply for 100Mbs traffic rates.

We now have four cluster sites and all AP’s have two 300ss’s in their circuit.

It may not be reccomended, however, we will not install 900 Mhz AP without them.


Thanks for that information. I am considering doing what you have done, unless I hear more otherwise against it. (It can’t hurt, right?) Do you have it set ot 10 full duplex or half? Also, what are you using for CMM protection (for the power supply)?

Thanks again.

All our AP’s are checked off @ 10 half and 10 full.

Line side surge protection for the CMM’s are from this company. (IT Protector)

we should really compare lightning notes to randy - lightning kicked out tail last summer too…one sit was hit 3 times in 3 months - we nearly lost our shirt on that one. we wound up eliminating 300ss’s as well (as they didn’t help us at all) - we are currently using hyperlink technologies lightning protection gear to protect our APs. The site damaged was either a water tower or a firetower…the installations on rohn towers, thus far, are undamaged.

see our documentation:

Anyone else want to chime in on this? If the 300SS are OK to use and will provide a added layer of protection, then I will use them, otherwise…

Will the Transsector or the other model from Hyperlink listed do better than just using 300ss?

Thank you.

If you sustain a direct hit, you will get hosed.

Near-by strikes and static are what really you are looking to protect against.

We use the 300SS on our ap sites, but just at the CMM end, we still run 100M Full, and the have not caused us any heartburn. I think the most important thing that you can do is leave a few feet of whatever structure you’re mounting to above the equipment. In cases where there is no already present structure above the mount point, we add a 10’ mast to the installation so that it is the topmost point. We’re in central Illinois, lots of lightnong, a few we’re pretty sure have been direct hits on our tower structure, and no damage at all (that we can tell so far, anyway) to any of our equipment. We ave had a number of client installations hit, though.

we have a site on top of a 40 foot pole on top of a pretty good size mountain next to a customer…he’s told us that AP has been hit directly (or the pole) on more than one occasion, but we’ve never lost it.

we’ve had other towers go down 4 times a month.

I have no idea what the differences are…we’ve upgraded all the stuff we have to the hyperlink stuff - but the only way to really know is to experience a strike…i do believe. :frowning:

Thanks for all the posts. I have 300SS’s on top and bottom of the tower, and have everything grounded to the tower, with a ground ring on the bottom.

Does the hyperlink or Transector unit offer any kind of replacement warranty concerning lightning?

My APs work great (so far) with 10mb full duplex.

I know a direct hit will fry most if not all, I am just trying to take precaution…

Thanks again,

J West