PROALL P Series, Service Manual, Page: 32 / 118

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5.4.10 BELT BYPASS

The belt bypass valve is energized automatically when
any of the downstream functions are set to “unload”. This
includes functions such as cement, AUX1 and color.

If any one of these unload functions are activated and the
belt is turning, then the belt bypass valve is not being
shifted.

A simple check is to look at the belt bypass valve coil /
connector and see if the indicator light goes on when an
unload function is activated. The technician can also
disconnect the cable and use a multimeter to check voltage
at the connector pins.

If the light does not go on, then it is likely that the cable
connection to the valve is loose or broken. Inspect the
cable for damage and replace if necessary.
5.5 FLOW METERS
WARNING!
The Sika VMZ flow meter is maintenance-free and cannot be repaired by the user. In case of a defect, the device
must be replaced or sent back the manufacturer for repair.

Check to ensure there is power to the flow meter itself by
looking at the indicator LED’s on the top of the meter.
o
The red LED is constantly lit to indicate that the
flow meter is operational.
o
The green LED blinks according to the frequency
of the output signal.
o
This blinking is not perceptible to the human eye at
frequencies above 30 to 40 Hz, so the green LED
appears to be constantly lit.

If there is no power to the flow meters check fuse F19
on the circuit board. If the fuse is replaced and blows again
then one of the flow meters is likely to have a short circuit.

Disconnect all the flow meters and connect one at a time to
find out which one is faulty.

If there appears to be power to the flow meter, but still not
working then it is possible the flow meter needs to be
cleaned (see cleaning instructions in maintenance section).

If the flow meter still does not read after checking power, K-
factor settings and cleaning then replace it.
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