Kistler-Morse KM LD360s - Manual (Page 26)

Appendix C: Troubleshooting the
Load Disc System
This section describes an output check and some common
problems. For each problem, one or more possible explana-
tions are listed. For each explanation, suggested solutions
are provided.
1. Connect the brown or red, white and black wires of the Load
Disc to the corresponding Test Meter terminals, as shown in
Figure C-1. Place the Load Disc on a stable surface.
2. Turn on the power to the Test Meter and set the
Simulate/Test switch to the Test position.
3. Verify the no-load output is between + 5mV and -5mV.
(This preliminary measurement specification simply
determines the condition of the Load Disc. If the output
reading is outside +/- 5mV, consult KM.)
4. Repeat Steps 2 and 3 for each Load Disc.
Load Disc
Figure C-1: Load Disc
connection to the KM
Test Meter.
Brown White Black
or
Red
Red White Black
ON
OFF
SENSOR
TEST
METER ADJUST
SIMULATE TEST
+EX SIGNAL -EX
Note: The “no-load”
condition is when the
Load Disc stands
alone without any
weight applied.
Functional Check: Measuring Output
Follow this procedure to test the Load Discs if you do not have a KM
Test Meter or if the no-load output using the Test Meter was out of
range for a Load Disc.
1. Set the ohmmeter resistance scale to accommodate a measured
range up to 20K ohms.
2. Put one DMM lead on the Load Disc’s black wire and the
other lead on the brown wire. Verify the brown-to-black
resistance is between 4.0K ohms and 6.0K ohms.
3. Place the Load Disc on a stable surface. Put one DMM lead
on the Load Disc’s white wire and the other lead on the brown
wire. Verify the brown-to-white resistance is between 8.5K
ohms and 9.0K ohms.
4. Put one DMM lead on the Load Disc’s white wire and the
other lead on the black wire. Verify the black-to-white
resistance is between 8.5K ohms and 9.0K ohms and within
40 ohms of the brown-to-white reading from Step 3.
5. Repeat Steps 2 through 4 for each Load Disc. If any reading is
outside the above ranges, contact KM for assistance before
proceeding with installation.
Functional Check:Measuring Resistance
Appendix C: Troubleshooting the Load Disc System
C-1