AMETEK 1995L Micro-Set PLS - Manual (Page 22)

Chapter 7: Troubleshooting
Installation and Maintenance Manual 18
Chapter 7: Troubleshooting
NOTE: Field repair beyond this level is not recommended.
7.1: Preliminary Checks
Check all system wiring connections at the LDT and at the programmer. Amphenol-type connectors on
the transducer and its cabling should be checked for tightness. A slight tug on all wire terminations
should verify a good connection. Push-on cable connectors should be checked for proper connections.
Verify that incoming AC voltage to the 1995 PLS is between 105V AC and 125V AC.
The following procedures are intended to aid in isolating system malfunctions to field replaceable
modules. These modules include the 1995 programmer, output relays, LDT and all interconnecting
cables. Once isolated, the defective module should be replaced and returned to the factory for repair.
The 1995 PLS is designed for use in an industrial environment and incorporates extensive transient
suppression circuitry. However, the same general installation rules should be followed that apply to all
microprocessor-based equipment.
Problems that can be attributed to extreme electrical noise or poor power quality include loss of/or
changes in program memory, loss of initialization, keypad or microprocessor lockup, sporadic outputs,
and damage to auxiliary input circuits.
7.2: Electrical Noise and Power Quality Consideration
7.3: Grounding
Circuit board level noise suppression circuits, ground planes, and cable shields all depend on a good
earth ground for proper operation. Our field experience has shown that the quality of the service
ground at many machines is marginal.