Powerware Horsepower Computer System ST-2400S - Manual (Page 17)

and the RPM sensor gear. Make sure that they are not loose
and that the runout of the RPM gear is not excessive. Check
the RPM sensor connector to be sure that it is tight. Check
the cable from the RPM pickup to the horsepower computer.
Check the power supply to the horsepower computer. Have
the horsepower computer checked.
Torque readings are
inaccurate Operate the unit using the ZERO and CHECK functions. If
the readings do not agree with the tables above, unit needs
to be repaired. Check the load cell mounting to be sure that
it is not loose. Check the dynamometer to be sure that it is
not in a bind. Check the torque calibration of the
horsepower computer. Check the power supply to the
horsepower computer. Have the horsepower computer
checked.
Residual Torque readings
are high when the
dynamometer is stopped. Pressure or force on the dynamometer absorption unit cradle
may be causing the residual readings. Remove the load cell
from the torque arm of the dyno to see if this removes the
excessive residual torque reading. Manually rock the torque
arm of the dyno. It should move freely and easily a
minimum of 0.5 inches (12.7 mm) up and down. The load
cell must be in a free floating position when not under load.
Re-adjust the torque cable and connectors if necessary.
Check the calibration zero of the horsepower computer.
The load cell may be damaged and need to be replaced.
Have the horsepower computer checked.
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