Thread: Variable Primary Flow

1. Not sure how I screwed the conversion up. But what I thought I did was multiply 8.6 x 4.33. Now I get the same answer as Chiller Freak when he divides 8.6 by 2.31. Thanks for straightening me out.

2. that looks a little different than the one I'm used to....as ours come right on the chiller...they look almost like a solenoid valve coil....but they do have a lighted bar across the top,,,red means no flow...green means flow....you will need relay board.....I had the info once and lost it....I know you can call them and they will tell you what you need....If you have problems let me know and I can find the info....Looks like your on the right track.

3. Originally Posted by mallron
Not sure how I screwed the conversion up. But what I thought I did was multiply 8.6 x 4.33. Now I get the same answer as Chiller Freak when he divides 8.6 by 2.31. Thanks for straightening me out.
1 foot of water = .43 psig Do you know the formula to figure actual gpm if you know the design GPM?
Last edited by chillerfreak; 04-05-2008 at 10:28 AM.

4. If you're talkin' square root(New delta P/ Design Delta P) x Design GPM = actual GPM, then I have it available to me, but I don't know it as in "know it by heart" and use it frequently.

5. Originally Posted by mallron
If you're talkin' square root(New delta P/ Design Delta P) x Design GPM = actual GPM, then I have it available to me, but I don't know it as in "know it by heart" and use it frequently.
...LOL....I hear you...the only reason I know it by heart is I've been using it just about everyday for the last 20 years....I'm no math wizard...I have a few formulas that I use written in sharpie on my service order binder so I don't forget....comes in pretty handy when trying to diagnose a problem...again I'm not trying to come across as a know it all.....I'm just a dumb fitter...do you know what's long and hard for a fitter?

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[QUOTE=mallron;1820265]Is this the switch you guys are talkin' about? If so, then I guess I'll need the model with AC relay output to prove flow to the machine.

Flow sensors with rugged stainless steel housing, easy setup and bar graph display - Series SI5

DC switching output

AC relay output

Flow transmitter with easy setup and bar graph display - Series SI

That one on the website is different than the one that comes on our chillers the carrier p/n is HR81LG015 the IFm p/n is a STO570 I didn`t see it on the website though. Ours is 24 vac then sends out 24vac to close a isolation relay.Which the chiller flow switch contacts are tied to.

7. Thanks guys, I knew the conversion, I just didn't read his statement carefully enough Very nice sensors though, I wish I'd heard about them a few years ago.

8. Originally Posted by ZZZRSC
Thanks guys, I knew the conversion, I just didn't read his statement carefully enough Very nice sensors though, I wish I'd heard about them a few years ago.
No worries. I type answers before I read the entire post all the time. Maybe too often.

9. [QUOTE=thegoodlistener;1820430]
Originally Posted by mallron
Is this the switch you guys are talkin' about? If so, then I guess I'll need the model with AC relay output to prove flow to the machine.

Flow sensors with rugged stainless steel housing, easy setup and bar graph display - Series SI5

DC switching output

AC relay output

Flow transmitter with easy setup and bar graph display - Series SI

That one on the website is different than the one that comes on our chillers the carrier p/n is HR81LG015 the IFm p/n is a STO570 I didn`t see it on the website though. Ours is 24 vac then sends out 24vac to close a isolation relay.Which the chiller flow switch contacts are tied to.

I sent them an e-mail explaining the application and what I wanted to do so hopefully I'll have an answer next week.

Thanks for all the help.

10. Originally Posted by chillerfreak
Mallron 8.6 feet= 3.7 psig

1 psig = 2.31 ft water column....not trying to be a no it all.....I just can't understand why Engineers can't use PSIG instead of feet???? my feet are what are tired at the end of the day!

I think you will be happy with the IFM....Good Luck!
FWIW,
From a balancing point of view, I'm thinking the manufacturer of the device, whether it be a chiller barrel or a flow station determines the units of measure that will produce the best resolution and accuracy. Whenever I'm doing any hydronic balancing, I follow the manufacturers units of measure.
Anyways, my hydronic manometer allows me to switch between units of measure with a touch of the keypad.
jogas

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