User's Manual

K02017-000 Rev. A
4
2.3 Electrical Installation
2.3.1. Grounding
Connect the reader directly to an earth ground. An earth ground can be established by driving a copper
clad ground rod into the earth. Make certain the DC resistance between your established earth ground
and the system ground is 50 Ohms or less. If direct connection to a ground rod is not possible, connect
the reader to an earth grounded cold water metal pipe (do not connect to copper fire sprinkler system
because it may have non-conductive couplings) or steel frames (building beams) that connect to earth.
Prevent ground loops by connecting both the cable shield and the negative line of the power supply to
one common earth ground point. Connecting different points to separate earth grounds may result in a
ground loop. Ground loops may cause poor read range and communication line interference resulting in
no code or improper code being seen by the controller.
In a multiple reader installation, connect all readers to a single earth ground reference point (common
ground).
2.3.2. Reader to Host Interface Wiring
Choose the appropriate interface for your
installation.