Ummm Help

[Unimatic1140]

I received the following email tonight:

Dear Sirs,

I am writing in regard to a thread posted in an italian site named "plcforum".
I am trying to create the automation for a today's dishwasher as the original
logical card is broken. As the user in my post said, a user connected to
" automaticwasher.org" should have found some help about this topic.

I know it is expensive to create the automation, especially if I consider
the time I need to do it, but it is something which I would enjoy to do because
of the automation itself more than the dishwasher.

So I have already created the all drivers PCB completed with power card to
let me get the inputs from the machine and drive the outputs to the machine
and all this using Visual Basic on my pc.

I just do not know the times and the process properly to avoid the machine
to leave the limestone on the dishes or/and avoid waste of water and electricity.

I am asking you, please, if you could give me some help or good directions to
find some solutions.

Thank you in advance,

yours faithfully,
Federico DIMITRI

Obviously there is a slight language barrier, but I believe Federico is asking about designing a dishwasher cycle to run off of a computer like I designed my Super Unimatic. Any suggestions as to a cycle for him?

 

[bobbyd32l]

I would say for a "Power" Cycle you could program something like this:

10 minute prewash with pump at high pressure
Drain/Filter flush
15 minute Hi Temp scrub with detergent with pump at high pressure (160° degree water temp)
Drain/Filter flush
10 minute low pressure high temp rinse (165° degree water temp)
Drain/Filter flush
15 minute High pressure Sanitizing rinse (165° degree water temp)
Drain/Filter Flush
10 Minute low pressure rinse with rinse aid (155° degree water temp)
Drain/Filter Flush
Heated or Non heated (selectable) Dry with fan assist

This cycle would be for heavy duty, no fine glass as the temps are too high, if he wants to use it for crystal or china, lower the temps by 15° and pressure to medium

What would really be cool is the pump was sophisticated enough it could alternate washing top to bottom rack, or a sensor system that would automatically adjust time and pressure according to the sediments in the water

 

[thor]

All European dishwashers have a salt container which reverse flushes twice during a normal cycle, to regenerate the resins which soften incoming water (just like the Mieles). Normally, these flushes happen just before the main wash and the last rinse. This is achieved through a two solenoid water valve. One of them is activated during the standard water fills, the other one is activated during the reverse flushes. These reverse flushes should be added to phases of the cycle.
Emilio

 

[thor]

Forgot...

Plus, a short (1 minute?) electrical signal to the detergent dispenser to open at the start of the main wash and another short electrical signal to the rinse aid dispenser to open and dispense a determined amount at the beginning of the last rinse.
Emilio

 

[toggleswitch]

I'd have a rinse first, before a wash. This would necessitate a double closed detergent cup.

1- This purges the lines of cool water (asuming a hot water connection).

2- Gets rid of the most junk possible without using detergent. This leaves it avaiable to wash machine pre-rinsed dishes, perhaps offering greater effectiveness. Then the next phase would be a wash. Could also be used to sense conditions present and adjust the wash and rinse time, temp, action, etc.