A PLC and a washing machine

Hi yall,
I am very new at the PLC. I am working on a project that involves controlling a commercial front loading washing machine with a PLC. I have been looking at the Allen Bradley SLC 500 series, and I was wondering what modules do I need to get.

The components in the machine that need to be controlled are the following:

3 water valves (220V ac)
1 drain value (220V ac)
1 pressure switch
1 door lock solenoid (220V ac)
1 door switch
1 power incidator light (220V ac)
1 Variable Frequency Drive (220V ac 3phase)
1 1HP 230\460 V ac 3 ph motor

I also have an Allen Bradley PanelView 600 with RS-232 and DEVICENET, in which the user would use to change cycle settings. The Variable Frequency Drive has analog voltage and current inputs to change the direction and speed of the motor.
My plans are to use the PLC and operator panel to drive the washing machine. I would like the PLC to control the speed and direction of the motor by suppling the VFD with the proper voltage or current, and for the PLC to react when the door is open and when the water level is not high enough. Any help or suggestions would be GREATLY APPRECIATED!!!

Thanks!

Just to be sure: this is a school, educational project, not a real thing to be sold for profit, right? I don't think it is a good idea to use an SLC500 for a commercially sold washing machine, for many different reasons...

Correct, this is not to be sold. This is for educational purposes only.

I would say using a SLC is a bit overkill - of course if that is all you have then what choice do you have?

You would be able to do it with a "brick" PLC eg Micrologix. I did in my class project.
HOWEVER I did not use a VFD.
Have seen commercial washers use PLC and VFD - worked well - so your setup is a realistic copy of real world.

You may be able to do it with out PLC control of VFD speed - let the ramps handle that just do PLC control motor direction.

Dan Bentler

AAHHH!!! Have a look at an Omron CP1L (shoebox/brick) - it will do the job at 1/4 the price and the HMI (5" colour LCD?) would also be inepensive.

There are also plenty of other options such as DL, Red Lion screens etc etc. SLC would cost you a bomb and heaps of space by comparison and be way over the top.

Bob you old pfart!

Saw your chance to advertice your Omrons did you?

See here for help on the program http://www.plctalk.net/qanda/showthread.php?t=12490

Just about any SLC will work, just use isolation relays, then you don't need to worry about the current and power of the I/O's, just match the relays up to your specification and match the coils up to your PLC

I think its a good project to show a school.. I would also include a e-stop relay circuit and SHOW the wiring so they will get the knowledge of that as well

If/when you do the project take some pictures and post them, I would like to see what you came up with...

Hope that helps....
Mark

HI

3 DO for 3 water valves (220V ac)
1 DO for 1 drain value (220V ac)
1 DI for 1 pressure switch
1 DO for 1 door lock solenoid (220V ac)
1 DI for 1 door switch
1 DO for 1 power incidator light (220V ac)
2 DO for 1 Variable Frequency Drive (220V ac 3phase)
(Assuming 1 DO for Start 1 DO for Stop and speed through POT)

Total 8 DO, 2DI needed.Go for potential free DO output and check the ampere rating of the DO card.
Regards

The discrete I/O are self explanatory. As for the speed to the VFD, I would not use analog, instead I would use set speed for each range triggered by a discrete input to the VFD.

Is that JesperMP in disguise?

The washing machine is a great idea. I teach machine troubleshooting and I use a washing machine as an example. Almost everyone has used one and knows what to expect of it.
Like above, please post your results.
Good luck

Thanks everyone for the input. The reason why I was looking at the SLC 500 series is because they seem to be plentyful on Ebay for very low prices. I am a computer engineering and electrical engineering major, so I don't have a lot of money to spend on a PLC (~ $300). Also, can a PLC be triggered from a Panelview 600 using the RS-232 port, in the event that the PLC I get does not have DEVICENET?

Here is a picture of the original machine. That is before the BIG modification.

Do you have the parts? or what parts do you have?

I can help, I have some old parts that I can not sell, the cosmetics are not the best, but they work just fine

I have a couple of pallets coming tomorrow and I know it has a lot of SLC parts on it

If you have the software (RSLogix 500) and a PC with a real serial port I have a 5/02 or maybe a 5/03 and the input/output cards that I can give you... the cable, power supply and rack you would need to buy (I have them also) if you can't find any cheaper then me I can put them all together for you... or just send you the other parts for free

You can do the inverter with digital out and just set up the drive with several different set points? depending on the drive you have

Send me a email if you are interested

Mark [email protected]

BobB said:

Is that JesperMP in disguise?

Click to expand...

No sorry mate, Jesper is a very common name in Denmark.

I've been trolling this forum and mrplc every day for some years now so I know that you like Omron (so do I).

I just laughed when I saw your post