Purpose of Decouple Loop Flow Meter in a Chilled Water System

systemcontrolte... The purpose of a decouple loop in a chilled water system is to help the programming decide to stage up another chiller or stage down the chiller. This type of control is generally found on systems with multiple chillers.
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[@jarmenkell385]

I am looking for this type of video for a long time explaining decoupler loop, finally here it is... Thanks a lot...

[@Systemcontroltech]

+Jarmen Kell thanks for watching and please subscribe for more

[@gt4033133]

Thanks for this information about the decoupler loop Flow meter explanation

[@Systemcontroltech]

Thanks for watching

[@happycamper548]

Seems like this is a very accurate way to stage up/down chillers. Are there any other ways to accomplish the same outcome?

[@Systemcontroltech]

There are others but this one takes its staging directly from the demand on the air handlers. You could also do some programming that would look at chilled water valve position instead of flow.

[@isr.01]

the system in my project is different. decoupler is not used for staging up and down, instead the staging up will begin when the temp in the main supply line is 1.4deg higher than the setpoint. and the stage down will begin when return water temp minus the supply water temp is less than the delta T setpoint of 5.6deg C. is it correct or more accurate if the staging will be based on the decoupler parameters? thank you.

[@Systemcontroltech]

There are many ways to control the staging. Just depends on the system.

[@antonkorolev8059]

4:09 you’re saying that when the secondary pumps slow down, the flow through the decoupler will slow down as well .., but it should increase no? When there is a 100% demand in the secondary loop, then there should be 0 flow in the decoupler

[@Systemcontroltech]

Flow through this decoupler loop will actually flow backwards depending on the secondary pump speed. The flow is what's used to stage the chillers

[@charlessoler904]

on this system are the valves at the ahu's three way or two way valves? Would the type of valves used effect the reading of the DP, and therefor the PID loops controlling your secondary pumps?

[@Systemcontroltech]

They are a mixture of two way and three way. As two way valves open, the secondary loop DP drops and causes the pumps to ramp up.

[@FreshCutFrenchFries]

Thx for the vid. Plz keep em coming!

[@Systemcontroltech]

+Incitatus Glad to help

[@elvischavez8269]

Thanks for useful video. What does the flow unit?

[@Systemcontroltech]

+Elvis Chavez This system uses an onicon flow meter in the loop.

[@joshthomas1064]

Where are you based out of? I just worked in Owensboro today! Small world! Thanks, great info!

[@Systemcontroltech]

+Josh Thomas thanks for watching

[@SombraLocs]

I just subscribed to your channel.

[@Systemcontroltech]

Glad to have you

[@SombraLocs]

Do you work on other BAS controls? Like Distech.

[@Systemcontroltech]

We actually use mostly Johnson Controls

[@kaFreon18]

Hi sir may i know what is the correct setting of Delta P of the secondary system in order to run the VFD secondary pump in a correct flow as per the load condition

[@Systemcontroltech]

It's common to see anywhere from 5 and in some instances as high as 10 degrees. It really depends on your system. Monitor the discharge temperature of your air handlers and adjust the set point accordingly. If the discharge temperature climbs with the valve fully open you may need a lower delta. Hope that helps.

[@rocha9158]

can you get a video showing a step by step installation?

[@Systemcontroltech]

Check my channel

[@neloxcampo9520]

hi Where do i learn basic Building Management System ? learning chillers, boilers ,pumps , air handlers, primary secondary pumps, and controls and stuff from scratch? thank you, also what software are you using? is that a simulator? thanks

[@Systemcontroltech]

+Nel Oxcampo you can find many videos on my channel

[@harryharding2123]

Can you demonstrate how to create an interlock

[@Systemcontroltech]

I will see what I can do.

[@neloxcampo9520]

where i can download that simulator? i hdont have ip address for metsys

[@Systemcontroltech]

+Nel Oxcampo this is not a simulator. The Johnson controls website only offers demonstrations.