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sethlocks

Do I need to use UTP for a passive balun? Elevator

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So, my customer wants to install a camera in their elevator. I have provided pricing for camera, DVR, etc, but left the elevator cabling up to the customer's elevator company. Turn out that they cannot provide UTP, or STP cable in the elevator traveller, nor will they give up a spare pair.

Elevator customer is offering to install, at an exorbitant cost, a new traveller cable. Choices are four stranded shielded 20 AWG pairs or four 14 AWG stranded cables. I may be able to get an RG6 installed, but it will cost about $1,000 more than the stranded wire.

My issue is the high capacitance with shielded cable, or noise with non shielded cable.

Passive balun, Active Balun?

 

Any advice? I was hoping that the elevator company would be a little more helpful.

 

Seth

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Although baluns are better-suited to CAT cable (CAT5/CAT6 giving best results), they will work on 20AWG or other cable pairs. The differences are that there might be a bit more noise picked up due to the lack of "twist" in the cable and there may be a slight "ghosting" due to the impedance mismatch. CAT3/5/6 cabling is 100 ohms impedance. Others will not be.

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Survtech, Thanks for the input.

I have another building I service and they have 18/2 for the elevator camera. It seems to work, but has a little noise every time the car begins moving.

Has anyone ever used shielded cable for this type of installation. Max distance, 200 feet.

Seth

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As Servtech has mentioned the balun is for impedance matching & unless they are the upmarket ones will have little effect on the induced noise. Why not use STP cable (shielded twisted pair) like Belden.

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I have one elevator cam that's using Cat5 and baluns and it's noisy as f#%*... of course, it's also a crappy, cheap camera and probably has a ground-loop problem as well. Customer is satisfied with it and didn't want me spending any more time on it, so... *shrug*

 

Meantime, I've run baluns over station-Z, 18/2 speaker wire, 20/2 shielded mic wire... only time it's been a problem was in one instance where I had to go from Cat5e to 18/2 to a different 18/2 and back to Cat5e before reaching its destination.

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The elevator cable price seems to high ,now the elevator cables with CAT5e prices

are only about %60 more expensive than the standard elevator cables.

It is better to install the cables together with the elevator technician.

Usually non elevator technicians are not allowed to make an installation at the elevator shaft due top the elevator standards.

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