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  1. #66
    Join Date
    Dec 2010
    Location
    west virginia
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    15
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    I think most issues begin right there....noone works there way up anymore, out of college and right to a supervisor postion. no hands on.. In other countries part of the education process is hands on work in the field working on yours and others designs, Why that cannot be done here is beyond me

  2. #67
    Join Date
    Aug 2009
    Location
    Prattville, Alabama
    Posts
    2,562
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    Is "ucp4" street slang for the AdaptiView panel?

  3. #68
    Join Date
    Jun 2010
    Location
    Miami
    Posts
    258
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    I don't think you will have near the problems you anticapate.

    Back in the late 90's I had some engineers show up for my new chiller plant. They wanted variable speed chillers with variable speed pumping through the evaporator. No 3 -way valves...no decoulping loop....nothing to maintain minimum flow through chillers......just one huge chill water pump on a VFD and nothing else.

    Made me more than a little nervous....even made York real nervous. I was used to Tranes, primary/secondary pumping, decoupling loops, 3-way valves, and all of that stuff. We argued, we fought, we even flew around the country together looking at equipment.

    Now that plant design has become the norm. I do things I never thought I could have before. Under the right conditons I run entering condenser water within a few degrees of leaving chill water.....I run several towers off one condenser water pump....and I can get an easy 1,500-2,000 tons out of a 750 ton machine at kw/ton rates that would make me feel like a liar if I quoted them.

    You need a team you can work with and you need to pick chiller barrels and cooling tower designs that work with your climates and loads. IMHO ragging on engineers cuts both ways. I don't think an operating engineer can look himself in the mirror and feel pride if they are still advocating constant volume, 3-way valve, chill water systems. Sure such systems are easy to keep operating but they are wasteful of natural resources to the point of being negligent.

    And yes, expect to become more proficent at BAS programming than your vendor....just no way around it.

  4. #69
    Join Date
    May 2010
    Posts
    1,295
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    Sorry that was my mistake, we run the Tracer™ CH530 on the chillers and they use the UCP3 board. We also have a comm4 board in them for communication with the Tracer Summit BCU.

    Russ, you state you run several towers/chillers off one condenser pump. If I am reading what you are saying correctly, you run one big pump for the chilled water and one big pump for the condenser water, and these two pumps can accomodate several chillers?

    Our setup is a bit different if that is in fact what you are stating, we run individual pumps for each of our chillers. I will post a print of our plant setup here in a few.

  5. #70
    Join Date
    May 2010
    Posts
    1,295
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    The proposed chiller is in the bold outline on the plans and will have VFD's on both pumps and compressor:
    You can right-click the image and save it to your computer, so that you can rotate it clockwise 90° for easier reading/viewing.


  6. #71
    Join Date
    Aug 2009
    Location
    Jurupa Valley, CA
    Posts
    1,877
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    Somthing that piping diagram doesn't show is valving. Where are the isolation valves located for the chillers?

  7. #72
    Join Date
    May 2010
    Posts
    1,295
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    The Bray Automatic Valves are located on each chillers, chilled water supply and condenser water return right at the chiller. There are no automatic valves yet on the chiller in the bold outline, but will be once it is replaced with the new chiller

  8. #73
    Join Date
    Aug 2009
    Location
    Jurupa Valley, CA
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    Are there no valves on the pumps for service? It would be more appropriate if the isolation boundary included the chiller and associated pumps (this would aid in implementing my above shown example system, also).

  9. #74
    Join Date
    May 2010
    Posts
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    Yes, there are manual valves on each side of each of the pumps. There are so many manual valves, it would be hard for me to identify them all lol.

  10. #75
    Join Date
    Aug 2009
    Location
    Jurupa Valley, CA
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    Quote Originally Posted by ZeroTolerance View Post
    Yes, there are manual valves on each side of each of the pumps. There are so many manual valves, it would be hard for me to identify them all lol.
    Luckily, Manual valves can become automatic valves rather easily.

  11. #76
    Join Date
    Oct 2014
    Location
    Northern Michigan
    Posts
    11
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    I'm going to jump in on this thread, from an on going personal experience. I have two 1000 ton Trane Centra-Vac's. (lead lag/weekly rotation) My building just completed it's 8th year of operation. My chilled pumps have always been on VFD's and my Chillers have VFD's. For the life of me, I didn't understand why my tower pumps were soft start using auto-transformers tapped at 80% then to 100% about 10 to 15 seconds later. So here we go, 125 hp vertical pump, slamming into a 40% open triple duty (instant head). Pumps were within temp specs but extremely warm to the touch and running full load of (going from memory) about 139 amps. This was all done at start up to maintain Chiller Condenser Delta P. (Chiller VFD's and Vanes taking care of Load)
    My background is residential. I only have 8 years in building plant management. Back to my pumps......
    We installed VFD's on our tower pumps. Working with my programmer, we installed pressure differential transmitters on the chiller condensers. (no more changing failed paddle flow switches for me) Opened the triple duty's to 100% open and now controlling the pumps to maintain condenser delta P. (demand option referenced of course)
    This is the result. My pumps are running somewhere around 68 amps. My pumps are cool to the touch. We're saving in the neighborhood of $24,000.00 a years in operating cost.
    This again is my experience in one building. We have added VFD's to supply and relief blowers and have seen a 12 to 14% reduction in operating cost even running at 100%. Our resident master electrician was so baffled, he contacted the VFD mfg and talked to their engineering department. Their explanation seems quite simple. The difference is going from utility to "conditioned" power. I can testify that what I've been told in VFD seminars has become reality. If you can reduce your motor to 80% with a VFD, you reduce your operating cost by 50%. I'm not an engineer and I can't explain all the why's and what for's but I can tell you that it works. The proof is in the electric bills.
    I'm a firm believer in VFD's. Installing them are a plus in my book even if you run at 100%. Work with your programmer, work with the engineers and I'm confident that you won't regret installing the VFD's. It opens the doors to a lot more opportunity to meet demand and save energy/money at the same time.
    Just my humble opinion.

  12. #77
    Join Date
    Aug 2009
    Location
    Jurupa Valley, CA
    Posts
    1,877
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    Quote Originally Posted by rgatlin View Post
    I'm going to jump in on this thread, from an on going personal experience. I have two 1000 ton Trane Centra-Vac's. (lead lag/weekly rotation) My building just completed it's 8th year of operation. My chilled pumps have always been on VFD's and my Chillers have VFD's. For the life of me, I didn't understand why my tower pumps were soft start using auto-transformers tapped at 80% then to 100% about 10 to 15 seconds later. So here we go, 125 hp vertical pump, slamming into a 40% open triple duty (instant head). Pumps were within temp specs but extremely warm to the touch and running full load of (going from memory) about 139 amps. This was all done at start up to maintain Chiller Condenser Delta P. (Chiller VFD's and Vanes taking care of Load)
    My background is residential. I only have 8 years in building plant management. Back to my pumps......
    We installed VFD's on our tower pumps. Working with my programmer, we installed pressure differential transmitters on the chiller condensers. (no more changing failed paddle flow switches for me) Opened the triple duty's to 100% open and now controlling the pumps to maintain condenser delta P. (demand option referenced of course)
    This is the result. My pumps are running somewhere around 68 amps. My pumps are cool to the touch. We're saving in the neighborhood of $24,000.00 a years in operating cost.
    This again is my experience in one building. We have added VFD's to supply and relief blowers and have seen a 12 to 14% reduction in operating cost even running at 100%. Our resident master electrician was so baffled, he contacted the VFD mfg and talked to their engineering department. Their explanation seems quite simple. The difference is going from utility to "conditioned" power. I can testify that what I've been told in VFD seminars has become reality. If you can reduce your motor to 80% with a VFD, you reduce your operating cost by 50%. I'm not an engineer and I can't explain all the why's and what for's but I can tell you that it works. The proof is in the electric bills.
    I'm a firm believer in VFD's. Installing them are a plus in my book even if you run at 100%. Work with your programmer, work with the engineers and I'm confident that you won't regret installing the VFD's. It opens the doors to a lot more opportunity to meet demand and save energy/money at the same time.
    Just my humble opinion.
    It is more a function of simply running the system itself more efficiently, than it is any electrical magic. In the case of your condensers, it is far less efficient running a pump that is too big for the flow, then throttling the flow down with the triple duty valve, than to simply only run the pump at the capacity you need. The same can be said for air handlers, where running a fan at full speed, and then controlling duct static with dampers is far less efficient than running the fan at just the right speed and letting dampers be full open.

    In either case, and especially in the condenser case, if you've got a fixed load (in the condenser case, a fixed condenser water flow), then the MOST efficient option is to have the pump sized exactly right for your system load. An exactly correct sized pump, running across the line, is still going to be more efficient than the wrong sized pump, running through a VFD. However, because it is often near impossible to accurately predict system losses, most times engineers simply design pumps a bit oversized, and count on throttling to balance things. This is why vfd's still save on single load systems, because the single load systems were never designed right from the beginning.

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