Jettech Metal Products F18-DP - Manual (Page 7)

Fill System & Rinse System
The dishwasher fill and rinse systems is practically the same system as they both used the same circuit.
The only difference is what is sending the signal to the water solenoid valve.
During the fill cycle, the water solenoid gets its signal from the pressostat. When the pressostat is
satisfied, it cuts the signal to the solenoid valve and sends power to the thermostats and the timer.
During the Rinse cycle, the water solenoid valve is getting its signal from the timer. When the time has
completed the rinse cycle than the solenoid is de-energized.
Because the detergent pump and the drain pump (if so equipped) are connected in parallel with the
water solenoid valve, they will all work at the same time. Why are they connected this way? Simple,
the detergent pump is connected this to inject detergent whenever new water comes into the
dishwasher. The detergent does not mix with the rinse system so it does not contaminate the rinsing
process with detergent.
The drain pump will
work whenever the
water solenoid
opens and this is to
avoid overflow
problem should the
pressostat becomes
defective and the
unit get stuck in a
fill cycle. Here it si
important to keep in
mind that this
scenario will only
work if the dynamic
(flow) water
pressure does not
exceed 25 PSI and the unit is capable of totally draining
within 1 minute. If any of those two factors exceeds the
limits then you can have an overflow situation.
The water solenoid valve will send water through the booster first and then water will travel to the
spray-arms as shown in the diagram below. The solenoid valve will fail under specific condition. High
pressure(>2.0 bar: >30 PSI) , high temperature(>60C:>140F), debris in water,
continuous work.
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