Application Notes

Wire

Use point-to-point Unshielded Twisted Pair wire, 24-16AWG (0,5-1,31mm), stranded or solid, Category 2, or better. Never use Shielded Twisted Pair wire (Exception: Multi-pair wire with an overall shield is OK). Do not use un-twisted wire or "quad-wire". The video signal may co-exist in the same wire bundle as other video, telephone, data, control signals, or low-voltage power. Always follow National Electrical Code, local, or other safety requirements. For safety, never put NVT signals in the same conduit with high-voltage power.

The wire must be installed with no bridge-taps, loading coils, talk-battery, or MOV type protectors. NVT's high-bandwidth signal will not pass through a telephone switching system, however multiple punch-blocks are OK.

Distance

Specified distance includes any coax in the path. It is recommended that the wire distance be measured to ensure that the capability of the NVT product is not exceeded. Wire resistance may be measured with an ohm-meter by shorting the two conductors together at the far end, and measuring the loop-resistance out and back. Compare against the chart below:
Resistance per 1000ft (300m) out and back.

24AWG (0,5mm) = 52ohms per 1000ft (300m)
19AWG (0,8mm) = 16ohms per 1000ft (300m)
22AWG (0,5mm) = 32ohms per 1000ft (300m)
18AWG (1,0mm) = 13ohms per 1000ft (300m)
20AWG (0,5mm) = 20ohms per 1000ft (300m)
16AWG (1,3mm) = 8.2ohms per 1000ft (300m)

Video signals traveling in opposite directions may co-exist in the same wire bundle up to 1,000ft (300m) or 2,000ft (600m) if Cat-5 or better wire is used.

Pan/Tilt/Zoom Signals

Video signals may co-exist in the same wire bundle as twisted pair control signals, such as RS-422, RS-485, etc. Passive NVT transceivers (such as the NV-214A-M) will transmit an "up-the-coax" P/T/Z control and video signal up to 750ft.

Power Supply Requirements

The NV-652R requires a floating 12-24VAC/DC power supply. The NV-452R requires a floating 24 VAC/DC supply. Up to eight NV-652Rs or three NV-452Rs can be powered from one 20VA 24VAC transformer. The NV-653T requires 24VAC/DC which may be shared with the camera, providing the power supply is not shared with other cameras. Power supplies are built into Active Receiver Hubs.

Power-Distance Chart

Using NVT's PVD products, cameras can be powered at extended distances, please refer to the chart below for more information.

Notes: wire can be category 2 or better. low-voltage camera power, video, and RS-422 or RS-485 may be sent within the same wire bundle. Do not run 24 VAC or 28 VAC in the same wire bundle with other telecom or datacom signals.