Hardy HI 2151/30WC Single-Scale Controller - Manual (Page 140)

HI 2151/30WC MANUAL
8-20
K - Load Sharing
and Load Sensor
Checkout
K
K1
Load cell wiring is
complete and
correct?
1) Does the mV signal increase in a positive direction.
2) If you receive a negative results, check if load cell is
mounted correctly.
a)
The arrow goes with the direction of force.
b) If there isn't an arrow, you must manually verify
the correct direction. A negative reading
indicates the load cell is upside down.
c) Load cells in tension will not reflect a negative
reading if install upside down. If upside down,
only the force applied by the cable would be
included in the weight readings.
d) If you are still receiving a negative signal, verify
load cell wire color code
K 2
Multiple load cells?
MAP the mV reading.
Balance the load
Monitor system for proper
operation.
Check out complete
1) Verify a positive reading from each load cell, using
Intergrated Technician's DVMTST, DVM MV.
2) Record the mV reading and compare each corner for
proper load sharing.
a) Proper load sharing should see only a difference
of +/- .5 mV.
b) Larger differences due to motors and piping,
should not exceed +/- 2 mV.
c) If there isn't any motors, valves, or piping to
explain the mV difference, adjust the
corners and balance the mV readings.
d) Use shims, or if equipped adjusting bolts on the
load cell mounting hardware.
e) Drawing a load cell map will help determine the
correct leg to adjust and in which direction.
Three load cells balance like a three legged chair.
1)
Using a sprit level, verify the vessel is vertically and
horizontally correct.
2) Verify if any height change will effect the attitude of adjacent
vessels or piping.
3) Adjust each legs to dynamically match mV outputs
4) Verify the mV readings and physical level when complete.
Four load cells or more present a challenge.
1)
Use Integrated Technician DVMTST, DVM MV
Determine the sum of the load cell signals and your target
mV setting for each load cell.
2) Read the output of individual load cells.
3) Adjust the load cell with the lowest reading to dynamically
match the target mV readings obtained in step 1.
4) Read the mV readings from each load cell to verify a proper
correction.
5) Repeat step 3 and 4 to achieve a proper load sharing vessel.
6) Verify the mV readings and vessel level when complete.