Milnor MWR09E5 Series General Operating And Troubleshooting page 48

Chapter 4. Testing and Troubleshooting
Figure 11: Level Switch Testing
.
Testing the Controller
4.2.2.3.
4.2.
that the microprocessor controller is receiving a signal from an external component, processing
the signal, and writing the results to the display. Further testing is required if a component is
actuated as described above, but the display does not indicate that it's actuated. By using the
information in Section 4.2.2.3.4.2 and the schematic manual, a qualified technician can determine
whether the problem lies with the component or the microprocessor controller.
Testing Outputs
4.2.2.3.
5.
devices in the machine by turning output relays on and off according to specific instructions. For
example, output relay K2 is dedicated to the machine drain. When this relay is energized, it
closes a circuit between pins 3 and 4 on MTA5 to provide power to the drain valve. Because a
spring in the drain valve opens the drain valve when power is not present, the drain is closed only
while output K2 is closed.
While all output relays can only be open or closed, two types of results can be achieved from any
output, depending on how it is used in the machine:
Direct outputs—These outputs, such as the drain output relay (K2) and the last rinse output
relay (K8), act as a switch in the circuit for the device to which they are assigned. Output K2
is described above. Output K8 closes when the last bath step of a formula begins, providing
power to the Last Rinse light on the control panel.
Indirect (signal) outputs—Indirect outputs signal other devices to operate. The most important
of these are the outputs that control how the motor inverter powers the motor to turn the
basket. When output K5 is closed, the inverter powers the motor to turn clockwise at wash
speed. Output K6 causes the inverter to run the motor counterclockwise, but still at wash
speed. When outputs K5 and K7 are on (contacts closed) at the same time, the basket runs
clockwise at extract speed. The chemical outputs (K13, K14, and K15) signal the chemical
supply system to provide chemical to the machine. Output K12 signals to flush the chemical
injection manifold.
CAUTION 17 : Avoid machine damage—This controller is designed to allow the
momentary actuation of outputs to verify proper operation. Continuous manual operation of
outputs may cause machine damage, especially if chemicals are actuated and not flushed
completely from the machine after testing.
• If chemicals are connected to the machine when outputs are tested, always activate the
flush output to dilute and flush out any chemical in the manifold and the machine.
PELLERIN MILNOR CORPORATION
Typical Level Switch
—The input testing procedures described in Section 4.2.2.3.4.1 verify
®
—The E-P OneTouch
A.
B.
C.
controller operates the chemical system and all other
Legend
Power and ground
terminals
Level adjusting screw
Mounting bracket