Page 1 of 2 12 LastLast
Results 1 to 13 of 15
  1. #1
    Join Date
    Apr 2011
    Posts
    10

    Cool Cooling tower control through a Tridium system

    We are currently looking to update the controls in our buildings to bring everything into one system. What I would like to do is move away from separate cooling tower controllers and have the chemistry controlled straight from the BAS. I think the only real challenge is the scaling of the inputs. Has anyone done this yet?

    I've seen controllers that will tie into your system but from what I've read it looks like these are just re-transmitted signals and the the tower controller is still doing the thinking. Any thoughts?

  2. #2
    Join Date
    Mar 2005
    Location
    Pacific Time Zone
    Posts
    4,198
    How much redundancy do you want? I'd want more.

    How often do you/your people check the towers, especially the water conditions? What happens if your BMS input starts reading incorrectly, saying all is fine, but your conductivity is through the roof?

    Having a tower go out of proper range creates way too much work. We have separate control on our towers but simply use the BMS to monitor the value(s) and alarm if the value gets too high/low. On ours we monitor the separator pump status and the conductivity. We alarm the pumps and alarm hi/low conductivity. We could control all this through the BMS, but I like as much local control as possible. Besides it minimizes the 'complexity' to a certain extent - "How do I force the blowdown open?" "Whoops forgot to put a local override switch near the blowdown valve, have to jumper it out/go thru the BMS."
    "How it can be considered "Open" is beyond me. Calling it "voyeur-ed" would be more accurate." pka LeroyMac, SkyIsBlue, fka Freddy-B, Mongo, IndyBlue
    BIG Government = More Dependents
    "Any 'standard' would be great if it didn't get bastardised by corporate self interest." MatrixTransform
    http://threedevilskennel.com/ - not my website.
    Versatile Hunting Dog Federation - www.vhdf.org/


  3. #3
    Join Date
    Nov 2008
    Location
    Colorado
    Posts
    6
    NCVTX:

    From your original post it is hard to determine if you want to control the water treatment chemicals or the towers themselves. Everything can be controlled by the BAS, but you have to ask yourself. Is it prudent to do so!

    What would propmt you to want to clutter your BAS with the task of controlling water chemistry?

  4. #4
    Join Date
    Feb 2008
    Location
    Purcellville Va.
    Posts
    715
    What would propmt you to want to clutter your BAS with the task of controlling water chemistry?
    I've also been thinking about controlling feed and bleed with the BAS. If you have the available inputs and outputs at a nearby controller then I'd think the program wouldn't be that hard to write.

    Crab
    Do you have a recommendation for a conductivity sensor? I'd at least like to add a sensor to the BAS.

  5. #5
    Join Date
    Sep 2008
    Location
    Cedar Rapids, IA
    Posts
    486
    Quote Originally Posted by 381engineer View Post
    I've also been thinking about controlling feed and bleed with the BAS. If you have the available inputs and outputs at a nearby controller then I'd think the program wouldn't be that hard to write.

    Crab
    Do you have a recommendation for a conductivity sensor? I'd at least like to add a sensor to the BAS.
    I agree that this is not a task you want the BAS doing. By all means monitor the conductivity and the run time of the chemical feed pumps and bleed, but leave them on local control. There is too much damage that can occur from improper management of chemical and bleed. Redundant conductivity sensors 1 on the BAS and 1 on the local control is best. But you must still check your chemistry manually frequently enough to catch problems.

  6. #6
    Join Date
    May 2002
    Posts
    9,564
    Quote Originally Posted by bob_scheel View Post
    ...this is not a task you want the BAS doing. By all means monitor the conductivity and the run time of the chemical feed pumps and bleed, but leave them on local control. There is too much damage that can occur from improper management of chemical and bleed....
    So, those automated chemical feeders are junk?

  7. #7
    Join Date
    Apr 2011
    Posts
    10
    Thanks for the response crab master. Good points. I am a BIG fan of redundancy,but I'm trying to determine the best choices on a tight budget. Any suggestions on a tower controller? I am looking at one from Aquatrac that seems promising. I can run up to 4 towers on 1 controller.
    Appreciate the advise.

  8. #8

  9. #9
    Join Date
    Apr 2011
    Posts
    10
    I was looking at the possibility of eliminating the cost of four new chemical controllers, while adding the ability to monitor the chemistry remotely. I am on a tight budget and every dollar counts. I think the point that crab master made about redundancy is a good one though and that is probably the way I'll go.
    Did you have a different idea?

  10. #10
    Quote Originally Posted by NCVTX View Post
    I was looking at the possibility of eliminating the cost of four new chemical controllers, while adding the ability to monitor the chemistry remotely. I am on a tight budget and every dollar counts. I think the point that crab master made about redundancy is a good one though and that is probably the way I'll go.
    Did you have a different idea?
    Dont reinvent the wheel man. integrate it via lon. By the time you are done "plink"ing with it..... this will be cheaper.

  11. #11
    Join Date
    Apr 2011
    Posts
    10
    Another good point. Thanks.

  12. #12
    Join Date
    Mar 2005
    Location
    Pacific Time Zone
    Posts
    4,198
    http://www.walchem.com/products/cont...ec_WDEC410.htm

    Is the brand we use, but not sure if that is the same model. We also added a monthly requirement to check the actual conductivity vs the controller value and then zero out the sensor as well. We had one that was taking care of 3 towers and we think it was out of cal for about 3 months, but the it was reading just above the low alarm value, but the actual value was 6000 us! Let's just say we were too reliant on the sensor reading correctly.

  13. #13
    Join Date
    Mar 2005
    Location
    Pacific Time Zone
    Posts
    4,198
    There may be something better than those but overall we've had pretty good luck. We have like 20 of them. All now have the accessory output card so we can get the 4-20mA value into the BMS.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event