Refrigeration Frequency inverter control

[Vedran0909]

Dear All,

Can somebody tell me where can i download some literature where it is explained the technology of working refrigeration system with example: 3 compressors, one is with frequency inverter, other direct with contactor, 6fans, PLC, 2 pressure sensors 4-20mA(LP and HP), temperature sensors(room and outside), etc.
It is for freezing meat for example.
There is one controller Eliwell EWCM9100 witch we would like to replace.

PLS if somebody can send me the link or by email the litterature explaining the ligic and control theory so we could write the program in PLC?

Any help is hugely appreciated!
Best Regards
Stanislas

[NoNickName]

Basicly you are asking us how to replicate, better yet to forge, a similar product to Eliwell EWCM9100, without the effort of developing it, trial-and-error and bugfixing it?

[Magoo]

Hi Vedran.
contact elliwell they may have a later version of controller with improvements that suits your application. Alternatively Carel have a range of controllers applicable as well. Off the shelf type systems.

[ NNN, that chip on your shoulder is fully grown to a pine tree ready for milling. ]

[chilliwilly]

Do you actually have any knowledge of PLCs or designing basic controls for refrigeration or any other plant or machinery?

It can take quite sometime to study the programming methods and the basic logic functions of PLCs, such as ladder, boolean, and subroutine. Which make of PLC are you planning on using? Basically they're all the same, but with subtle differences.

Klockner Moeller brought out a really basic PLC some years ago, but I tended not to use on anything major as its logic function and capability was too limited for the kit that I worked on at the time. However I did use it as a modification to certain machines such as palletizers and conveyor end take off box fillers. There should be enough logic function for what you are trying to do, and they can be expanded for more inputs and outputs, and the beauty of them is they can be programmed from the PLC without the need of a hand held programmer or a laptop.

Maybe better to stick with tried and tested control methods like what's already on there, it will be a quicker install or uprade. Theres no real advantage with using PLCs on walkins or aircon unless a process is being used such as cutting the beasts up and weighing them into portions. And in the case of the aircon, a small building services management system could be designed to control maybe four or more independently piped splits. Or a central packaged unit thats ducted to control the zoned grills/registers.

[Vedran0909]

Yes.

pls.

We need the technology, it does not have to be eliwell.

[Vedran0909]

i am very good at programming Omron plcs, that is our business, machine automation.

[Vedran0909]

Do you actually have any knowledge of PLCs or designing basic controls for refrigeration or any other plant or machinery?

It can take quite sometime to study the programming methods and the basic logic functions of PLCs, such as ladder, boolean, and subroutine. Which make of PLC are you planning on using? Basically they're all the same, but with subtle differences.

Klockner Moeller brought out a really basic PLC some years ago, but I tended not to use on anything major as its logic function and capability was too limited for the kit that I worked on at the time. However I did use it as a modification to certain machines such as palletizers and conveyor end take off box fillers. There should be enough logic function for what you are trying to do, and they can be expanded for more inputs and outputs, and the beauty of them is they can be programmed from the PLC without the need of a hand held programmer or a laptop.

Maybe better to stick with tried and tested control methods like what's already on there, it will be a quicker install or uprade. Theres no real advantage with using PLCs on walkins or aircon unless a process is being used such as cutting the beasts up and weighing them into portions. And in the case of the aircon, a small building services management system could be designed to control maybe four or more independently piped splits. Or a central packaged unit thats ducted to control the zoned grills/registers.

Can somebody tell us the technology, for example, compressor 1 works by LP sensor ovar PID. Fans work with HP sensor. Power works by room sensor, etc....

[Vedran0909]

Basicly you are asking us how to replicate, better yet to forge, a similar product to Eliwell EWCM9100, without the effort of developing it, trial-and-error and bugfixing it?

No, just the technology we need, does not have to be eliwell.

Just step by step how the system should work.

1. Power regulation over room temp sensor
2. Compressor1 inverter PID control LP probe, 2-3 steps
3. Fans step control over HP probe

Etc....

[Segei]

I think that to program PLC we need 2 different area of expertise:refrigeration and programming. You need to find somebody with refrigeration knowledge. Unfortunately, you can't download this knowledge from internet.

[NoNickName]

I'm ready to help you out, as long as I get payed for my work.

[RCassist]

There's a ready system produced in Germany by PSC-Systec, that is also controlling that the compressor stays within his functioning envelope. The system is already developped and is running on several installations.

[persim]

Is this industrial og commersial ref? In other words small compressors.
I'm used to working with Howden and Vilter screwcompressor but this is industrial and requires
a lot more of sensors to monitor any situation which is critical for running the compressors.
Have done what you are looking for but we are speaking of compressorunits where the electrical
motor is 400V 550kW

[D.D.KORANNE]

You need the rack controller to operate sequentially compressors ( to switch on & off ). And depending upon the load on compressor you can time out te compressors via sensors .Such controllers are available with DIXCELL, DANFOSS, CAREL to name a few .......