Earth-Grounding Keri NXT Controllers
You should make a quality earth ground connection to all Keri NXT 2D or 4D controllers to ensure the best possible operating conditions
for the controllers. An earth ground brings all electrically neutral lines to the earth's surface potential (essentially to a zero
potential). Without a quality earth ground connection, the access control system may appear to operate correctly, but can
be extremely susceptible to transients and electromagnetic interference on data and power lines. In addition, while the
system may appear to work correctly now, improper or non-existent earth grounding can cause erratic system reliability in
the future, resulting in possible equipment failure and/or more frequent service calls.
This document applies to the following Keri products:
- Keri Standard NXT 2D/4D controllers.
- NXT-MSC (Mercury-Powered) 2D/4D controllers.
2.0 Proper Earth Ground Benefits:
- An earth ground protects a controller from electrical transients such as power surges (which also provides a degree of
safety for an installer).
- An earth ground provides a path to ground for electrical interference helping to minimize data and communication
problems for controller to host communications.
3.0 Typical Sources for an Earth Ground are:
- copper shrouded ground rod
- cold water pipe (must be a metal pipe, galvanized or copper – it cannot be PVC)
- steel building framing member (however, the building's frame must be embedded in the earth)
- electrical system ground (at the breaker/fuse box)
- telephone system ground
4.0 Earth-Ground Cable Type
- a single conductor, solid strand, AWG 18 wire (a larger gauge is always acceptable)
- green with a yellow tracer (but are also often solid green)
5.0 When Making an Earth-Ground connection:
- Each controller should have its own, unique earth ground. Do not daisy-chain earth ground connections between
- When routing the earth ground wire, make it the shortest path to ground as possible.
- Verify a solid earth ground connection has been made before turning on controller power for the first time.
- Periodically verify the quality of the controller's earth ground connection.
6.0 Make the Earth-Ground to Controller Connection at:
NXT controllers have Ground Lug J6 at the top of the PCB near the TB10 power connector.
Make your NXT earth ground connection directly to this lug.
Earth Ground Connection on NXT Controllers
NXT 2D/4D Controller Factory Reset
Keri recommends resetting NXT controllers the first time these controllers are powered on. Also, under certain circumstances NXT controllers may need to be reset. Note: Factory resetting a standard NXT controller will restore the controller to a ...
Standard NXT Controller Setup
NXT Controller Setup NXT 4 door controller Introduction This document covers the basic configuration of NXT controllers in Doors.NET software. It assumes Doors.NET has already been successfully installed on your host PC, the software license has been ...
How to Assign a Standard NXT Controller an IP Address Without Using Doors.NET
You can assign an IP address to a standard NXT controller using the Keri NXT AutoConfig Update. The utility will detect any unassigned controllers and will allow you to configure the controller with a valid IP address. This utility is installed when ...
NXT 2D/4D Controller Specifications
Specifications Size (Enclosure): 13.125” H x 10.625” W x 3.06” D (33.34 cm x 26.99 cm x 7.77 cm) Size (PC Board): 5.6” H x 6.6” W x 2.55” D (14.28 cm x 16.83 cm x 2.55 cm) Weight (In Enclosure): 4.95 Lbs (2.25 Kgs) Input Voltage: + 12 VDC nom. (10 - ...
NXT 2D/4D Basic Controller Setup in Doors.NET
Introduction This document covers the basic configuration of NXT controllers in Doors.NET software. It assumes Doors.NET has already been successfully installed on your host PC, the software license has been activated, and the gateway has been ...