Gram GSV185 Vi control priciple

Hi all,

Please advise me, I am changing Gram controller for GSV185 to PLC S7 because I cannot find spare part.
This compressor model has 2 solenoid valves for capacity adjust and 2 for volume ratio adjust.
Problem is I can calculate Vi setpoint but I do not khow what I have to think about if I want to increase or decrease Vi solenoid valve. For example, do I have to wait until temperature setpoint reach then adjust Vi?

Thank you,
Keerati

Hi Keerati,
What you can not find the spare part?

Hi, keerati :)

Quote:

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Originally Posted by keerati

Hi all,

Please advise me, I am changing Gram controller for GSV185 to PLC S7 because I cannot find spare part.
This compressor model has 2 solenoid valves for capacity adjust and 2 for volume ratio adjust.
Problem is I can calculate Vi setpoint but I do not khow what I have to think about if I want to increase or decrease Vi solenoid valve. For example, do I have to wait until temperature setpoint reach then adjust Vi?

Thank you,
Keerati

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... why not change/replace with UNISAB II ... there you have all you need ....

Best regards, Josip :)

Hi Josip,

I cannot find new controller, I am already changed controller to PLC.
But I am not sure about Vi control concept.

You can use cheaper Grammatic 1502

Hi Keerati, contact me at the e-mail

Hi, keerati :)

Quote:

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Originally Posted by keerati

Hi Josip,

I cannot find new controller, I am already changed controller to PLC.
But I am not sure about Vi control concept.

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...hm... not sure but will try to find something to help you .... cannot understand:confused: why you did not ask immediately after damage of your controller ..... btw is that one Grammatic 1502 or 2502 .... or something else....

we had broken one G1502 and replace it with UNISAB II client is more then satisfied...

Best regards, Josip :)

Hi Josef,

What's the email address please??

Best regards,
Keerati

Hi Josip,

Many thanks for suggestion.
That's 1502. I am not the one who decide to use PLC control. My customer select this way because they cannot find spare part in Thailand. I am control engineer who make PLC program for them.

Best regards,
Keerati

If you have to ask this question, your employer should question your ability to solve his problem! There are many places that you could find information on the fundementals of VI control, Try the OEM manual for the compressor. Not a flame, just an observation!

Thank for observation ,even you have no sufficient knowledge.

Hi, keerati :)

Quote:

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Originally Posted by keerati

Thank for observation ,even you have no sufficient knowledge.

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this above is not nice:off topic:

.....unfortunately I do not know the exact algorithm used in 1502 controller.. for Gram185

please check attachments ;)

....as you can see Vi depends on pressure ratio .. i.e. when you change capacity then you change Vi...


.... of course when Vi is automatic ... otherwise we change it 2 times per year ... summer and winter..;)

hope that will help a little..

Best regards, Josip :)

Hi, I'm looking for the Digital Input Module used on standart compressor control packages for 240 VAC

It made by CRYDOM Mexico, yellow modules . Help me please