Surge suppression on AP side of CMM2

Having trouble maintaing network connectivity (pings) on wired side of AP’s when using 300SS’s on shielded Cat5 cables going up towers.

We already lost a whole cluster and CMM Micro by near lightning strike, when installed as recomended, without surge suppression on AP side of CMM’s.

Has anyone seen this kind of connectivity issues, and what are some solutions?

Any help would be appreciated.

Canopy does NOT recommend using 300SS’s for AP’s and BH’s etc. If you do, you can split the cable and run the ethernet through the SS, and route the power around the ss. Confusing yes, but I remember having alot of trouble running in 100baset when going through a SS. Im sure your CMM is grounded.

wirelessSolutions, could you give me more details about it? Im doing exactly the wrong thing (i think).

When I bought a lot of 20Mbps BH units, they came with ethernet supressors, each Canopy with one Surge Supressor. I assumed it MUST be installed, so I installed them all.

I have the connection from the ground with shielded cat-5 cable to surge supressor and 1 mt. un-shielded cable from the supressor to Canopy.

So, is this wrong?? Why is the 300SS for? How must be correctly installed? When it must be installed?

You will help me a lot if you answer me… thanks in advance :wink:

My reply was based off of a tech support conversation with Ben Sexton. Maybe someone will fill in here, but the company I worked for didn’t even use SS’s for their AP’s and BH’s. We would make a 2 to 1 cable.

Wires 123 and 6? would be crimped down into a rj45 jack and plug’d into the Switch. Wires 4578 would also be crimped down in a seperate rj45 jack and plug’d into the CMM. At the other end of this cable (the 1) would be the full cable crimped down and plug’d into the BH/AP.

This didn’t stop lightning from frying a AP or two, but it’s just how we seperated the sync and power from the data. In other words we did not use the CMM as a switch.

When we added more equipment to the equation, we used 300SS’s to “extend” the cable and also to protect it. We had it hooked up just like you mention and it worked fine for the time being.

Thinking back, the only problem we experienced with 300SS’s is the inability to run at 100baset… 10 base t was the only way the pings would stay solid.

I really don’t think I answered a single question in this post. :oops:

We had SS on 3 AP locations. The types of things we were experiencing is when you reboot a CMM for whatever reason then the AP woul dnot come back up and you had to go on site to unplug and plug the AP from Power. Another thing we saw was the fact that you couldnt get to the GUI interface remotely. And on one other instance we had packet loss…

What configuration did you end up with? Were you able to leave the surge protection in the circuit?

I failed to mention in my first post that this was a new installation. The 6 AP’s and CMM Micro we lost had only been up for 4 days.

Our tower grounding grid has a #0 down conductor, connects to an underground ring. Each leg of the tower also connects to this ring, Over 200 feet of grounding rods all tied together in the ground ring.

The guide wires are all grounded and tied to the down conductor at each point on the tower

We were only able to get the Ohms down to 7.

We still lost the equipment from inductance on the Cat 5.

The power side of the CMM was OK. Other equipment on the same 120V circuit was unhurt.

This is why we feel the need to protect the equipment from inductance on the Cat 5 cables.

We have tried other manufactures of surge protection and are having the same intermittent packet loss issues.

We have discovered that breaking the drain wire connection at the bottom can immediately bring the radios back online, however, this does not work every time.

Our next move is to isolate, with gas isolators, the drain wires.

This will break the ground loop and isolate each radio’s drain wire from each other.

There has to be a way to better protect this equipment.

Thanks for your replies.

APC makes a rack mountable surge supressor frame ( i think 24 slots) that you then have to buy each individual SS. It worked pretty well.

Great news!!!

Hard setting the negotiation rate to 10 half on the AP’s appears to correct the packet loss and connectivity issues.

Cycled power on the CMM’s multiple times and all AP’s came up every time. Never, has that happened before.

Apparent problem:

The insertion of surge protection devices in the AP circuits induces enough resistance on the data pairs that it infers a longer cable distance, exceding the 100 meter standard, thus preventing the 100Mbs throughput. Our longest cable is 250’.

Thanks to all of you that replied.

wireless solutions, you were right on!

Although running in 10baset instead of 100baset kinda sucks, its better than nothing! Glad I could help! 8)

Now all you have to worry about are collisions due to half-duplex mode. Whippee! :wink:

Actually, we left 10 half and 10 full enabled.

According to Motorola, the max aggregated throughput of a 900 AP is 4 Mbs, when 2X is enabled.

If that is the case, then 10 Mbs should be plenty.

Thanks again

how about in a 5.7 Ghz AP? does anyone here knows what’s the max throughput? Can we also configure our CMM ports to 10 Mbps coz we also experience same problem using SS and running in 100 mbps.

Thanks :slight_smile:

hmmm…this could be the reason i am getting authentication problems on my one tower…it was installed by a different crew, who put SS on each of the APs…

Yes were have the same types of problems. AP’s hanging and not being able to access them until after a hard reboot. I’ll test the setting the AP’s and BH’s to 10mb-half instead of full, today and post my results.


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. :wink:

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