Tri-Stepper Input Voltage
electrical
Description
The stepper input voltage is out of the 9V to 17V range for three seconds, and the steppers on that board are powered off until good power is reported.
Activation Conditions
The stepper input voltage is reported out of valid range (9V to 17V) by MSM for three seconds as timed at stepper board.
Unit Behavior
Engine and Electric Operation: Alarm only. Steppers on board with problem disabled (Powered OFF) until good power reported from Stepper Board at which point they are re-enabled.
Reset Conditions
10 Seconds of good voltage reported from all steppers.
Corrective Actions
1. Check voltages - Check input voltage at 1-2MSM-22. 2. Check Fuse F5 a. Visually check fuse Verify correct fuse, and check fuse holder for damage, see Figure 2.5. Replace fuse as required. Clear alarms, restart and check for repeat alarm(s). b. Check voltage through the fuse. If fuse is blown, replace it. c. Check wiring from PM-13 to 1-2MSM-22. Verify there is no physical damage to harness, and no damage, moisture, or corrosion in connectors. 3. Disconnect Stepper Valve(s), if alarm goes away: Check operation of suspected valve. Refer to Section 8.8.7.