values are computed and displayed. This process is repeated continuously while the unit is in operation.
Computer Function Switch:
The computer function switch is used to turn the system power ON/OFF and to control the functional operation of the horsepower computer. The function switch has four positions ( “OFF”, “ZERO”, “CHECK”, and “RUN”).
In the “OFF” position, the power to the horsepower computer (and the load cell, etc.) is turned “OFF”. The power is turned “ON” in the other three positions of the computer function switch.
The horsepower computer has two user controllable self test modes (“ZERO” and “CHECK”). These can be used to test much of the horsepower computer’s internal circuits for proper operation. In the ZERO position, internal test signals are fed into the RPM and TORQUE measurement circuits. In the ZERO position of the function switch, these signals should result in readings of zero on all four displays. If the reading of any display remains substantially different from zero (more than +/- 1 or 2 counts) when in the zero mode, some type of malfunction of the unit is indicated.
The second user controllable test mode is the CHECK mode. In this mode, internal test signals are fed to the RPM and TORQUE measuring circuits to simulate normal operation of the unit at about 37.5 % of full scale torque. The actual readings shown on the displays of the unit depend on internal factory set optional settings – principally the full scale torque value (which corresponds to the size of the load cell being used with the unit). The RPM display should read about 4000 RPM (+/- 1 or 2 counts) on all units. The Torque display should read about 37.5 % of the load cell rating. Refer to the tables below for the proper readings of the Torque and Power displays for your unit. The Power reading should agree with the power you compute from the actual RPM and TORQUE readings (within +/- 1 or 2 counts) using the above formulae for the horsepower or kilowatts.
Load Cell Rating | Torque | Power (HP) |
100 | 37.50 | 28.56 |
200 | 75.00 | 57.10 |
500 | 187.5 | 142.8 |
1,000 | 375.0 | 285.6 |
2,000 | 750.0 | 571.0 |
5,000 | 1875 | 1428 |
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