Troubleshooting; Error Messages; Common Problems And Solutions - Honeywell SC Series Installation Instructions Manual

SC 2000, SC2001, SC3004

11.8 Troubleshooting

11.8.1 Error Messages

See "Error Messages" on page 73 for information relating to error
messages.

11.8.2 Common Problems and Solutions

Erratic Display
• Check electrical connections for continuity and the trans-
ducer's wiring code from its Certificate of Calibration.
• Make sure that the displacement on the transducer is con-
stant.
• Check the input to the (+)Signal ("+SIG") and (-)Signal ("-
SIG") pins with an RMS voltmeter in its "AC Voltage" mode.
Using a voltmeter in its dc Voltage mode will always display
0.
+OVLD or -OVLD on Display
• Indicates that the voltage across the (+)Signal ("+SIG") and
(-)Signal ("-SIG") pins is overranging or underranging the
amplifier circuit. Make certain all wires are connected prop-
erly, the "CALIBRATION DATA -> FULL SCALE VRMS" menu item
is set correctly, and that a calibration has been performed
per "Calibration Procedure" on page 40.
• If you move the armature back to its electrical null point and
you still see this message, the (+)Excitation ("+EXC") or (-)
Excitation ("-EXC") pins may be shorted to the (+)Signal
("+SIG") or (-)Signal ("-SIG") pins.
Analog Output Incorrect
• Make certain of the type of Analog Output (voltage or cur-
rent) that the channel is equipped with; see "Identifying the
Output Type" on page 46.
• Use the DIAGNOSTICS -> DAC FULL SCALE and DIAGNOSTICS ->
DAC ZERO SCALE menu items to force the Analog Output to a
known output. Then, adjust your readout device, panel meter,
PLC or data acquisition system to match.
• Check the output selection jumpers; see "Output Selection"
on page 46.
Auxiliary Function Pins Not Operating
• Make sure that the AUX1 FUNCTION or AUX2 FUNCTION SETUP
menu items are set correctly; if they are set to DISABLED
then they will not operate.
• The Auxiliary Function ("AUX1" and "AUX2") pins must be
connected to pin 10, not pin 8, to activate them.
Sensitivity to EMI/RFI
To obtain maximum immunity to electromagnetic or radio frequen-
cy interference, make certain that the shields of the transducer
cables are connected to the "cable shield connection screw"
on the rear panel of the instrument. See "Connection of Four- or
Five-wire AC/AC-LVDT" on page 39, "External Arrangement of
AC powered SC2000" on page 10 and "External Arrangement of
Model SC3004" on page 15.
Non-linearity at the end of the LVDT's mechanical range
Most LVDTs have a usable measuring range that is smaller than
their mechanical range. See "Electrical Null and Transducer
Mounting" on page 45 for information on establishing the LVDT's
electrical null point to insure that the LVDT will be operated in its
usable measuring range.
008-0608-00
Rev. G,
Honeywell Sensing and Control 47