How much cable do you need for a lift camera?
Travel height to cable length to coil pairs, with the two ways the cable can be hung.
The number everyone starts with is the building height. The number that matters is the loop length, and it depends on where the cable is fixed.
Fixed at mid-shaft (the usual way)
The camera cable hangs from the travelling-cable bracket near the middle of the shaft. When the car is at the bottom the cable reaches down to it; when the car is at the top the loop folds up. The cable length needed is roughly half the travel, plus the drop from the bracket into the car, plus loop allowance: cable length ≈ (travel ÷ 2) + 3 m + 10 %. For a 40 m travel that is about 25 m of flat cable, plus fixed round CAT6 from the bracket to the NVR.
Fixed at the shaft top
Some sites run the camera cable from the machine room down the shaft to the car. Then the cable must reach the bottom floor with the car: cable length ≈ travel + 3 m + 10 %. For the same 40 m travel that is about 47 m. This is simpler to route but wastes cable and doubles the loop weight — the GI rope version, CC-8261G-90, is the right cable when the loop gets long.
Coil pairs
Channeltech lift cables come in 90 m coil pairs. One coil serves one lift up to about 80 m of cable; a building with two lifts in a bank uses one coil pair. For four lifts, two pairs; and so on. Round up — spare cable in the box is cheap, a second shaft visit is not.
Do not forget
- The fixed section: round CAT6 from the bracket or machine room to the NVR is a separate cable — measure it separately.
- The 60 m rule: keep the flat-cable run for an IP camera on PoE under 60 m. If the loop is longer, move the junction box closer to the middle of travel.
- One camera per cable: do not daisy-chain cars.
