Prevent Electrical Discharge; Remove Power; Selecting A Location - Spectrum Controls 1769 User Manual

User's Manual Pub. 0300241-01 Rev. A

3.3.2 Prevent Electrical Discharge

Electrostatic discharge can damage integrated circuits or
!
semiconductors if you touch analog I/O module bus connector pins or
the terminal block on the input module. Follow these guidelines when
Attention
you handle the module:
•
Touch a grounded object to discharge static potential.
•
Wear an approved wrist-strap grounding device.
•
Do not touch the bus connector or connector pins.
•
Do not touch circuit components inside the module.
•
If available, use a static-safe work station.
•
When it is not in use, keep the module in its static-shield bag.

3.3.3 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.

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 ratings. The maximum I/O module rating is 8,
Chapter 3: Installation and Wiring 3-3