
CALIBRATION AND MAINTENANCE UM344-2
September 1995
POSSIBLE CAUSE CORRECTIVE ACTION
Loop Wiring Failure Check for 12 Vdc minimum across SIGNAL +/- terminals in transmitter terminal
compartment.
Check polarity of loop wiring at both power supply and transmitter.
Check that loop resistance is between 250Ω and 1100Ω.
Check for loose or broken loop wiring at power supply terminals, Supply
Barriers (if used), junction boxes, and transmitter terminal compartment.
Check for disconnected or broken Current Sense Resistor.
Check for short between shield and SIGNAL + loop wire.
Check for accumulation of moisture in transmitter terminal compartment.
Check for the proper type and length of loop cable and for electrical
interference between the loop cable and any adjacent cables in a cable tray or
conduit..
Comentarios a estos manuales