Remove Power; Selecting A Location; Section 2.3 Power Requirements - Spectrum Controls 1794sc-IRT8I User Manual

Section 2.3
Power
Requirements
User's Manual Pub. 0300242‐01 Rev. A

2.2.3 Remove Power

Remove power before removing or inserting this module. When you
!
remove or insert a module with power applied, an electrical arc may
occur. An electrical arc can cause personal injury or property damage
Attention
by:
•
Sending an erroneous signal to your system's field devices,
causing unintended machine motion
•
Causing an explosion in a hazardous environment
Electrical arcing causes excessive wear to contacts on both the module
and its mating connector and may lead to premature failure.

2.2.4 Selecting a Location

Reducing Noise
Most applications require installation in an industrial enclosure to reduce the effects of
electrical interference. Analog inputs are highly susceptible to electrical noise. Electrical
noise coupled to the analog inputs will reduce the performance (accuracy) of the module.
Group your modules to minimize adverse effects from radiated electrical noise and heat.
Consider the following conditions when selecting a location for the analog module.
Position the module:
•
Away from sources of electrical noise such as hard-contact switches, relays, and
AC motor drives
•
Away from modules which generate significant radiated heat, such as the 1794-
OB32. Refer to the module's heat dissipation specification.
In addition, route shielded, twisted-pair analog input wiring away from any high voltage
I/O wiring.
The module receives power through the bus interface from the +5V dc/+24V dc system
power supply. The maximum current drawn by the module is shown in the table below.
5 VDC 24 VDC
80 mA 240 mA
The wiring of the terminal base unit is determined by the current draw through the
terminal base. Make certain that the current draw does not exceed 10A.
Total current draw through the terminal base unit is limited to 10A.
!
Separate power connections may be necessary.
Attention
Methods of wiring the terminal base units are shown in the illustration below.
Chapter 2: Installation and Wiring 2-3