10.0
TROUBLESHOOTING
www.maxcessintl.com
MAGPOWR Spyder-Plus
MI 850A320 1 M
Page 40 of 60
10.4
Load Cell Calibration Problems
Problem
Possible Cause
Solution or Diagnostic
Cannot calibrate load cells.
Load cells wired
incorrectly.
Table 1 below gives voltages for various
wiring errors. All voltages are measured
with respect to Term.21.
Opens on Term.23 and Term.24 cannot be
found by measuring voltages. Remove
power from the Spyder and measure
resistance between (Term.23 and Term.25)
and again between (Term.24 and Term.25).
For one load cell both readings should be
about 260 ohms. For two load cells both
readings should be about 130 ohms.
Message “Sensing roll too
heavy”
The roll supported by the load cells must
weigh less than ½ of the total load cell
rating (the sum of the two).
This message also appears when there are
load cell wiring errors. See “Cannot
calibrate load cells” above.
Message “Out of range at Max
Tension”
The Spyder has calculated that the load
cell will be overloaded if the Maximum
Tension specified is applied to the sensing
roll. The Spyder will recommend a lower
Maximum Tension to avoid this problem.
Message “Signal too small at
Max Tension”
The Spyder has calculated that the load
cell will have very light loading even when
Maximum Tension is applied. The Spyder
will recommend a higher Maximum
Tension to avoid this problem. However,
there is a strong possibility that a load cell
was chosen with too high of a rating.
Spyder will not calibrate if the force applied
to the load cell at Maximum Tension is less
than 1/8 of the total load cell rating.
Message “Load cells are
overl
oaded.”
The load applied to the sensing roll during
calibration has exceeded the rating of the
load cell.
Message “Load very small.
Maybe shorted.”
The signal read by the Spyder after load
was applied is very small. There may be a
short between Term.23 and Term.24.
This message also appears if the
calibration load was never applied to the
sensing roll.
