Despatch MIC1422 Controller - Manual (Page 11)

7
2.2 Wiring Guidelines
Electrical noise is a phenomenon typical of industrial environments. The following are
guidelines that must be followed to minimize the effect of noise upon any
instrumentation.
Installation Considerations
Listed below are some of the common sources of electrical noise in the
industrial environment:
•
Ignition Transformers
•
Arc Welders
•
Mechanical contact relay(s)
•
Solenoids
Before using any instrument near the device listed, the instructions below
should be followed:
1. If the instrument is to be mounted in the same panel as any of the listed devices,
separate them by the largest distance possible. For maximum electrical noise
reduction, the noise generating devices should be mounted in a separate enclosure.
2. If possible, eliminate mechanical contact relay(s) and replace with solid state relays.
If a mechanical relay being powered by an instrument output device cannot be
replaced, a solid state relay can be used to isolate the instrument.
3. A separate isolation transformer to feed only instrumentation should be considered.
The transformer can isolate the instrument from noise found on the AC power input.
4. If the instrument is being installed on existing equipment, the wiring in the area
should be checked to insure that good wiring practices have been followed.