mikefamig said:
Interesting about the protected side needing to be longer than outside and it's a deal breaker for me. What is the logic behind that?
I'll leave the LB unless I have trouble with it. AS you know, I have had trouble with crimping the B connectors with a plier. I didn't strip the wires though and will try that the next time.
@ Neuro: For everything but most mission critical I end up using the trusty T& B 112M. Have been using the same pair daily for 16 years. I just happened to pick up the real deal on a whim after going into the history of the B-connector...curious as to if they existed on the 'bay and if their splice quality was better or the same as my T&B's. There's more involved, but I'll leave off at that.
@ RAL: Those crimpers are no different than the old 112M I use or their counterpart. In actuality they're really for the insulated terminals (butt, spade, ring) like Sta-kons and not B-connectors. They perform a 2 stage crimp for insulated terminals: Crimp the barrel and collapse the colored portion (as in a sta-kon) around what would be the single conductor entrance point. The ratchet portion performs nothing other than forcing the user to go through the entire crimp motion, not really going to have an effect on an over/under crimp on a parallel die anyways, but the same holds true with normal crimping pliers also.
@ Mike: I put a Ditek on each end of the building to building run with a clamping voltage just above the normal service voltage. In the case of a 950, the clamping voltage is just too high to really protect a data bus or panel, but it's better than nothing (ring voltage in the neighborhood of 90+V and around 48 constant) and that will definitely cause damage to the bus or zone on a panel. While it's better than nothing, it's the wrong device for the application, but good for phone lines. Also, 950's are transorb based products...enough hits and they flash to ground; they weaken on each surge they take. Not a huge deal with telephone (just a hum on line) but can cause very weird things to happen on a panel with no EG reference. For an example within this state, I have an access control system at Foxwoods. Gets hit by lightning often. Had surges on the cabling but until we got the clamping voltage value just right, devices would still cook even though the surge was installed properly.
The protected side connection is supposed to be longer than the ground wire to allow the protector enough time to act. While we're talking fractions of a second, if the path to ground is shorter than the protected cabling, it'll bleed the transients to EG before it hits the electronics (in theory). We don't care about protecting the field wiring per se, only the equipment at each end of the run (IE: panel, PTZ cam, IP encoder, NVR, etc.)