Specifications

CI-1 and CI-8 Communications Interface
2-6
COMMUNICATIONS INSTALLATION
The following general rules apply to all communication cables, 20mA loop and RS-232.
1. Plastic cable clamps and tie-wraps are acceptable. Staples must never be used to secure
communication cables.
2. Communication cables from two or more CI-8 ports may be bundled together and may share
a common conduit run; however, bundling or sharing conduit runs with cables of other
electrical or electronic devices must be avoided. Bundling should be loose. Refer to local
electrical codes for permitted conduit sizes.
3. Avoid splicing communication cables. If splicing is necessary, try to maintain as much 'twist'
as possible in the twisted pairs. Protect the splice with shrink tubing to avoid shorts and
ground faults.
CI-8 20 mA LOOP TO ACU CONNECTION
The 20mA loop connections are made with dual twisted-pair cable. The cable wire must be a
minimum of 24-gauge and unshielded. The maximum distance between the CI-8 and an ACU
is 2000 ft (610 m).
Figure 2-5 shows a single ACU connected to a 20mA port on the CI-8. Each CI-8 20 mA port can
support a maximum of four ACUs; wiring for multiple ACUs is shown in Figure 2-6.
Figure 2-5: Single ACU 20mA Loop Connection