AmeriWater MRO3, Operation & Maintenance Manual

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MRO 3 & 4 MANUAL
44
98-0140
Rev. F
9.2 CONTROLLER TROUBLESHOOTING
CAUTION: Hazardous voltages are present when power is applied to the unit. Care
should be taken when troubleshooting any of the input power or output
circuits. When disconnecting or connecting any board or accessory, be
sure power is unplugged.
Before contacting AmeriWater for technical help, verify the programming of all Setpoints,
check the display and check the status of all lights and indicators. The more information
available when you contact us, the easier it will be to determine the source of the problem.
Standard setpoints and drawings of the controller and pc boards can be found in Section 6,
MRO Controller.
PROBLEM INVESTIGATION CORRECTIVE ACTION
System Inoperative Is the yellow CPU active
LED blinking?
If no, is the green power
LED, DS1 Lit?
If no, is the fuse OK?
If no, replace the fuse.
If yes, with a voltmeter, verify
power is applied to the
power terminals L1 and L2.
If power is applied to the
power terminals and the
other checks are OK, the pc
board is defective and
should be replaced.
If no power is applied to the
board, check the power
wiring to the system.
Display Blank Is the green power LED,
DS1 lit?
If yes, is the CPU active
LED, DS9 blinking?
If yes, adjust the display
contrast adjustment, R3. Is
the display still blank?
If no, refer to the system
inoperative section.
If no, replace the board.
If yes, replace the board.
Inlet Valve Will Not Operate Is the system in standby?
If no, are any shut down
conditions active?
If no, is the inlet LED, DS8
lit?
If yes, with a voltmeter, verify
if there is power on the inlet
terminals. Is there power?
If no, replace the board.
If no, replace the board.
If yes, check the valve and
wiring.