Spectrum Controls 1769sc-HART Modules - Manual (Page 21)

Chapter 3: Installation and Wiring
User's Manual 0300215-03 Rev. A
3-3
3.3.3 Remove Power
!
Attention
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
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.
3.3.4 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 1769-IA16.
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.
Power Supply Distance
You can install as many modules as your power supply can support. However, all 1769
I/O modules have a power supply distance rating. The maximum I/O module rating is 8,
which means that a module may not be located more than 8 modules away from the
system power supply.
Figure 3-1