Surge Suppressor for ePMP 1000 GPS AP and PTP


We lost two (2) ePMP 1000 5GHz GPS APs this week due to a passing storm/power outage.   These were connected to the Cambium 600SS surge protectors at the bottom of the tower and before the entrance of the building.  One switch port was lost.  Both PoEs are still good.  One surge protector is still testing good (at least powering a test AP and passing traffic).  The other surge suppressor we are uncertain of.

In the ePMP Portfolio PDF document (, it shows that the Powering Method is either 30V PoE or 802.3af for a GPS Sync AP radio.  So I have several questions concerning the compatible surge suppressors.

Should we continue to use:-

    (a) the 600SS surge suppressors or should we be using (or upgrade to) either

    (b) Gigabit Surge Suppressor,

    (c) Cambium's C000000L033A 56V surge (,

    (d) Wireless Beehive surge GigSurge (

We are also planning to install some ePMP 1000 2.4GHz APs (GPS sync) models.  Will these surge protectors also work with this model series?  And will these work through an 802.3af PoE switch?  Planning on not using PoE adapters (bricks) for the sites moving forward.

Interestingly I just noticed as we were preparing the replacement radios (APs) that there is a ground screw terminal located on the AP.  Should we be using this?  If so, what size screw should be used since the radios don't ship with a screw in the box nor on the radio?

Lastly, if we were to upgrade an ePMP 1000 GPS Sync AP to a ePMP 2000 AP, will the same surge protectors work an 802.3af PoE switch?


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The 600SS device is not compatible in general with 802.3 PoE derivatives, and was designed to Canopy (PMP100 and PMP450) and earlier radios, with up to 100Base-T Ethernet and proprietary ~20VDC PoE. I am attaching the circuit diagram 600SS_iss_e_sht1.pdf I received many years ago from Motorola. 

The Cambium's C000000L033A 56V you can use universally on every 10/100/1000Base-T Ethernet, also with 802.3af PoE, which can also be used to power most new ePMP radios with specified this type powering, usually as alternative to proprietary Cambium's PoE. I am attaching a datasheet Cambium_C000000L033A_56VDC_SS.pdf.

Cambium has also C000000L065A Surge Suppresor for 10/100/1000Base-T Ethernet, to be used with their proprietary PoE <30VDC, see the datasheet SS_GigabitEthernetSurgeSuppressor_03272018.pdf. Beware, this device CANNOT BE USED when powering radio from higher then 30VDC voltages, because internal semiconductor components, able to carry very big currents for microseconds, can be destroyed when even a small current of tens of milliamperes will flow through them for long time. Especially be careful when you use modern switches with PoE because usually PoE is enabled by default. If you connect 30V SS to port of such switch, you will destroy the components in SS, as the switch delivers >50VDC and is able to provide several watts of power, which semiconductors will not withstand. Unfortunately there are no appropriate warnings in CN literature.

These new CN SSs have astonishing design, because after mounting them on the pole or on the wall, the grounding screw terminal is almost impossible to tighten or check. In old 600SS design it was much more better engineered.

Another question is what for CN has developed these SS to be mounted convenietly on poles, but much less conveniently on the wall, as all new CN radios have internal 1 or 2 Joule surge protection circuits inside a radio. The SS is therefore most needed at the building entry down the cable running from the radio, where wall mount is likely the most needed.

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"These new CN SSs have astonishing design, "

Almost everything they build has an astonishing design... but yeah, what is their deal with putting the ground lugs on the backs of things where they can't be checked/changed/connected after the SS or AP is mounted ?  And the pole mount design that makes the SS less than easy to mount on walls and especially walls with vinyl siding. Oh and the top screw has to be put on the wall and the SS hung on it (nothing I like more than adjusting a #@#&* screw to get it so that it's not to far out but also not to far in for the stupid SS to hang on.) .Oh and do you need a little bit longer screw or shorter screw ? Well not just any screw will work because the head of the screw has to fit in the hanger on the SS ! GRRRR  Also the screw being like that makes it harder to know exactly where the SS is going to hang/mount so you have to measure and mark to know exactly where the screw has to go so the SS goes exactly where you want it. 

Any other SS you just hold in the spot you want it to be, maybe set a level on it (Try that on the ePMP SS!) and two screws and done ! Now the SS is firmly held and securing the ground wire is easy. Not cambium though noooo that would be to easy, they want you trying hold the unattached SS while simultaneously handling a screw, two washers, and the ring terminal with ground wire attached to it (so it doesn't want to turn the way you need to line the screw up with the hole) and a screw driver... half of them end up without the washers installed because they got dropped while trying to line everything up and now you can't find find them. How many hands do they  think installers have ? Is the ePMP team aliens ? Is that why their designs seems so bizarre sometimes ? Do they have 4 hands to hold lots of tools and parts at once and and array of tentacle legs so they can comfortably stay in place on a 12/12 pitch and easily juggle all these things ? Not to mention advance tech quantum phones and notepads with air HUDs so their horrible radio GUI is usable.

They now recommend mounting an SS at the point of entry to the building (per NEC) and also at the radio end (so two per install).  So two of them on every install...

On our towers everything has SS at the top close to the radio radio and the bottom at the enclosure (not ePMP SS's though) .