Grounding or Equipment Issue

While adding a new grounding block, near the main service ground, I believe I felt voltage on one of the ground wires attached to either the 450i body or one on the two 600SS.

Did not have a chance to trace it back to which device it was connected to but will do so as soon as the weather breaks.

Is the length of my #10 ground wire too long and if so will adding a grounding rod, closer to the radio, bonded to the main service ground rod fix the problem?

Do I have a bad 600SS?

Do I have a bad 450i?

Install Overview


#6 Ground Wire attached to mast

450i radio installed with shielded CAT5e w/ drain wire w/ shielded connector 

#10 Ground Wire attached to 450i radio

Cambium 600SS installed at radio

#10 Ground Wire attached to 600SS

Cambium 600SS installed at building entry

#10 Ground Wire attached to 600SS

#6 Ground Wire runs down the mast about 25 feet and is attached to a grounding rod the #6 Ground Wire then continues an addition 50 feet or so to the main service ground.

The three #10 ground wires run parallel with the #6 ground wire all the way to the main service ground.  They are NOT attached to the first ground round they are only attached to the main service ground rod.

All CAT5e cable runs from the POE injector to the radio are shielded w/ drain wire w/ shielded connectors.

The POE injector in connected to a APC power strip and the power strip is connected to a APC UPS w/ line conditioning.

A little more information.

Disconnected the three #10 ground wires from the grounding block and tested each one with a multimeter.

Multimeter was set to DCV 200 m

First #10 =  12.5

Second #10 = 13.2

Third #10 = .1

Did not trace them back to their origin as all three along with the #6 mast ground wire in run thru multiple sections of conduit.

For now I will assume that the First and Second #10 are attached to the two 600SS surge protectors which are located at the radio and at the point of entry and the Third #10 is connected to the radio ground lug.

Does this voltage indicate a problem?

Anybody...  Anybody....

It is my understanding the 600SS is not compatible with 450i.  You need to use a 1000SS.


I seem to be going in circles.  

You tell me that the 600ss is the incorrect unit and another Cambium employee tells me that it is the correct unit.

Which is it???

I have received no contact from support other than we are looking into it.

Please give me a call.  Cambium has my number.

or even an LPU like the one used for the PTP 

From the Cambium 450 Users Guide

What is confusing the issue is a few things.  Hopefully, I can clear them up.

First, you mention a 900 MHz PTP link, but also call it 450i.  This product is actually based on the 450 product, and is similar hardware to the 900 MHz SM. (In opposition to this, the 900 MHz AP is a 450i, and requires the Gigabit surge suppressor).

A 900 MHz PTP 450 is NOT technically based on the 450i hardware, therefore you (and the User Guide) are correct in that you should be using the 600SSH as the surge suppression device for these radios.

That said, the support ticket is definitely the right way to track this issue to closure. I will follow up and try to get some resolution.

1 Like

This post is going in the wrong direction very fast.

It is not answering my question(s) which I posed in the post.

Which I am still waiting for a response.

Sorry for the confusion but I refer to it as the 450i because:

1.  The reseller stated that it was a 450i.

2.  Cambium rep stated that it was a 450i.

_ am qu_ckly remov_ng _ from my vocabulary and as soon as _ can f_nd my pl_ers _ w_ll be remov_ng the _ key.

Stay Safe

It's also a PTP 900 link you're talking about in the PMP 450 forum... :)

I think we're all clear on what's being discussed, and as I said above, I am following up on the ticket internally.  I think there is more information that we're going to ask you for Rob.

_ knew that would be brought up.

Th_s _s the forum w_th all the act_on.

_f you l_ke _ can l_m_t my post to that forum as lonely as that w_ll be.

Stay Safe