Powerware Horsepower Computer System ST-2400S - Manual (Page 16)

The following table is useful for you to determine that cause of any problems that you
might be able to fix yourself.
Problem
Possible causes and remedies
No indication on displays.
Power LED is not lit. There is likely no power to the unit. Check the power supply
to be sure it is plugged in. Check the fuse on the front panel
of the unit. Replace ONLY with the correct ½ amp fuse. DO
NOT use a slow blow or higher value fuse as this can result
in severe damage to the unit.
Power LED comes ON
and OFF erratically Check to be sure the power supply is plugged in securely.
Try another outlet. Make sure the power connector is
fastened tightly to the front of the unit.
Power LED flashes ON
and OFF regularly Power supply voltage is too low. Check the power supply or
battery. The supply voltage must be at least 12 Volts with
low power supply “ripple” for the unit to operate properly.
Unit blows fuses Power supply voltage may be too high. The power supply
voltage should be less than 20 Volts DC or damage to the
unit will occur. Send the 2400S for repairs if the unit blows
fuses when the power supply voltage is less than 20 Volts
DC. Use only the correct size ( ½ amp) and type (fast blow)
fuse – or severe damage to the unit will likely occur.
RPM display reads zero
all the time, or is erratic Check the RPM pickup on the dynamometer. Be sure that it
is not loose. Check the wiring from the RPM pickup to the
horsepower computer. Make sure the RPM sensor connector
is tight. Have the horsepower computer checked.
Torque display reads –
EEE or some other value
all the time (or is erratic) Check the load cell on the dynamometer. Be sure that it is
not loose. Check the cable between the load cell and the
horsepower computer. Make sure the Torque Sensor
connector is tight. The load cell may be bad and need to be
replaced. Have the horsepower computer checked.
Printer doesn’t work (or
works erratically) Check the printer cable between the horsepower computer
and the printer. Be sure both ends are tight in their
respective connectors. Make sure the printer is plugged into
a proper power source. Perform a “self test” on the printer to
be sure it is working. Have the horsepower computer
checked.
Horsepower or Kilowatt
readings are low or not
correct Check the torque calibration. If Chassis dyno, the tires may
be slipping on the dynamometer rolls – increase chain
tension to obtain more “over center” action between tires
and rolls. Excess speed often causes power losses. If farm
tractor, the PTO clutch may be slipping (refer to the tractor
repair manual). Engine may not be performing properly.
Have the horsepower computer checked.
RPM readings are
inaccurate Operate the unit in the CHECK function. If the reading is
not 4000 RPM, have the horsepower computer repaired. If
the CHECK reading is 4000 RPM, check the RPM pickup
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