Spectrum Controls 1762sc-IF4OF4 - Manual (Page 19)

Chapter 2: Installation and Wiring 2-7
User’s Manual Pub. 0300247-01 Rev. C
wires specified by the thermocouple manufacturer. Using the incorrect type of
thermocouple extension wire or not following the correct polarity will cause
invalid readings.
 The module does not provide loop power for analog inputs. Use a power supply
that matches the input transmitter specifications.
Outputs
 Load resistance for a voltage output channel must be equal to or greater than 1K
Ω.
 Load resistance for a current output channel must remain between 0 and 500 Ω.
Grounding
!
Attention
The possibility exists that a grounded or exposed thermocouple can
become shorted to a potential greater than that of the thermocouple
itself. Due to possible shock hazard, take care when wiring grounded or
exposed thermocouples.
!
Attention
USE SUPPLY WIRES SUITALE FOR 20°C ABOVE SURROUNDING
AMBIENT
!
Attention
UTILISER DES FILS D’ALIMENTATION QUI CONVIENNENT A
UNE TEMPERATURE DE 20°C AU-DESSUS DE LA
TEMPERATURE AMBIANTE
 This product is intended to be mounted to a well-grounded mounting surface
such as a metal panel. Additional grounding connections from the module’s
mounting tabs or DIN rail (if used) are not required unless the mounting surface
cannot be grounded.
 Under normal conditions, the drain wire (shield) should be connected to the
metal mounting panel (earth ground). Keep shield connection to earth ground as
short as possible.
 Ground the shield drain wire at one end only. The typical location is as follows:
o
For grounded thermocouples or millivolt sensors, this is at the sensor
end.
o
For insulated/ungrounded thermocouples, this is at the module end.
Contact your sensor manufacturer for additional details.
 Refer to Industrial Automation Wiring and Grounding Guidelines, Allen-
Bradley publication 1770-4.1, for additional information.
Noise Prevention
 Route 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 15.2 cm (6 in.) of separation for every
120V of power.
 Routing field wiring in a grounded conduit can reduce electrical noise.
 If field wiring must cross ac or power cables, ensure that they cross at right
angles.