Spectrum Controls 1756sc-IF8u - Manual (Page 26)

14
ControlLogix ™ Universal Analog Input Module
Figure 2.2. Terminal block diagram with keying
Wiring Your Module
Follow these guidelines to wire your input signal cables:
• Power, input, and output (I/O) wiring must be in accordance with Class
I, Division 2 wiring methods [Article 501-4(b) of the National Electrical
Code, NFPA 70] and in accordance with the authority having
jurisdiction.
• Peripheral equipment must be suitable for the location in which it is
used.
• Route the field wiring away from any other wiring and as far as
possible from sources of electrical noise, such as motors, transformers,
contactors, and ac devices. As a general rule, allow at least 6 in.
(about 15.2 cm) of separation for every 120 V of power.
• Routing the field wiring in a grounded conduit can reduce electrical
noise further.
• If the field wiring must cross ac or power cables, ensure that they cross
at right angles.
• To limit the pickup of electrical noise, keep thermocouple, RTD,
millivolt, and milliamp signal wires as far from power and load lines as
possible.
• For improved immunity to electrical noise, use Belden 8761 (shielded,
twisted pair) or equivalent wire for millivolt sensors; or use shielded,
twisted pair thermocouple extension lead wire specified by the
thermocouple or RTD manufacturer. Using the incorrect type of
thermocouple extension wire or not following the correct polarity may
cause invalid readings.
• Ground the shield drain wire at only one end of the cable. The
preferred location is at the shield connections at the ControlLogix
chassis. (Refer to IEEE Std. 518, Section 6.4.2.7 or contact your sensor
manufacturer for additional details.)