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Type: Posts; User: mccann

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  1. Replies
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    I hate those supply/return contraptions in 7-11s....

    I hate those supply/return contraptions in 7-11s. The return would be so cold, but the room where the customers were was warm. They should shoot whoever came up with that. Had to add freeze stats to...
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    If 5 sensors in an area read 71.0*f but one...

    If 5 sensors in an area read 71.0*f but one sensor reads 74.3*f and this has a trend average of measuring within 1.1* and the supply, return, building walls, refrigerant temperatures, static...
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    There would not be sweating big fat hogs because...

    There would not be sweating big fat hogs because there would be 10 or 20 sensors in the room. Supply and return of every vent and around desks and walls. It would tell you when the batteries are at...
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    Artificial Intelligence opinion

    Are you excited about the future of HVAC? I read about this HVAC control system that continues learning. http://www.vigilent.com/
    So far, they seem to specialize in computer rooms. It keeps years...
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    527

    Leak lock the male threads starting about 2...

    Leak lock the male threads starting about 2 threads up so not to get Leak Lock into the system . Make sure the threads are clean. If brass fittings are loose or it is steel pipe, I put teflon tape on...
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    Any good temperature alarms?

    Any opinions on a good little set of temp alarms for a restaurant. I hate the interface on most that I've seen over the years. There must be some decent ones now days with all the technology...
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    558

    One more, less likely possibility I've seen, was...

    One more, less likely possibility I've seen, was high superheat. As moisture hit the less cold, dryer parts of the coil, it no longer clings to the coil. One time, after cleaning the coil, it...
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    Someday I would like to experiment with a unit...

    Someday I would like to experiment with a unit and graph all the values that can be measured as I add refrigerant from 0% to way over charge, at standard indoor and outdoor. Then repeat the...
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    709

    No. It has R407c, two 10 ton txvs, a top coil...

    No.
    It has R407c, two 10 ton txvs, a top coil and bottom coil, 3 compressors in tandem, One big one and two smaller, hot gas bypass, hot gas reheat, electric heat. The control panel in the photo...
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    709

    Thanks; I'll know more after today when I have...

    Thanks; I'll know more after today when I have seen it myself. Navigation of the controller is usually my first confusion when deal with any new equipment.
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    580941580951580961

    580941580951580961
  12. Thread: Part changers

    by mccann
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    1,861

    Keep increasing the size of the breaker or fuse....

    Keep increasing the size of the breaker or fuse. The answer will come in a flash.
  13. Replies
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    709

    Military AC units

    Anybody know about these military units? I'm told I will be changing a compressor on a EEI (Engineered Environments, Inc.) It has tandem Trane 15 ton or so compressors. It sits on a trailer with flex...
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    908

    When measuring ohms and amps on a small 480 volt...

    When measuring ohms and amps on a small 480 volt crankcase heater; if you don't have a sensitive meter, you may think it's open.
  15. Replies
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    11,639

    Looks like a better design than the Sporlan one....

    Looks like a better design than the Sporlan one. Better price too. What will not be connected to our phone in the future?
  16. Replies
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    1,658

    If it saves money, we will be seeing this...

    If it saves money, we will be seeing this everywhere soon. Plumbers have been using it for years. Low bid gets the job. Good thing o-rings never fail, ha ha. I wonder how it will do with heat pump...
  17. I work on a bunch of Lieberts with 407c. All have...

    I work on a bunch of Lieberts with 407c. All have clear sight glasses.
  18. I work on a bunch of Lieberts with 407c. All have...

    I work on a bunch of Lieberts with 407c. All have clear sight glasses.
    I have seen some refrigeration systems that never clear the glass. When it's running nice, the refrigerant will "river" by the...
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    651

    It is a York,...

    It is a York, YCIV0177VA46VABBXTXXXXXLXXXX44XXXXX...........Typical giant model #.
    The sensor starts reading high by about 10*. It has happened on two different same model units which are right next...
  20. >Dual sensors everywhere: Subcooling, superheat,...

    >Dual sensors everywhere: Subcooling, superheat, ambient, motor temps, supply, return, amps. Differences in adjacent sensors will alarm a fault.
    >Artificial intelligence learns and controls...
  21. It's important to have a solid column of liquid...

    It's important to have a solid column of liquid at the TXV to have it function well. That's the idea of having some subcooling (indicating fully condensed liquid). I would try to get a clear glass...
  22. Replies
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    651

    Temp sensors fail on York chillers

    Is it common to see a lot of temperature sensor failures on a York chiller? This one chiller we do has had the chilled water sensors fail multiple times. Anybody else seen this?
  23. Replies
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    You are not wrong. I do not do such things...

    You are not wrong. I do not do such things lightly. I'm going to speak to our salesman and let him explain the cost risk analysis to the customer.
    This was one reason I was asking for some numbers...
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    What is the math formula you used?

    What is the math formula you used?
  25. Replies
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    1,010

    There are no taps or vents. Two 3" gate valves...

    There are no taps or vents. Two 3" gate valves isolate the chiller from the loop. In the winter they shut the gate valves and open a bypass valve so water is just pumped back to the tanks.
    I...
  26. Replies
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    It's fresh potable water. They circulate it...

    It's fresh potable water. They circulate it through the chiller and feed off the tank to mix cement in their trucks. They must have some make up water to keep the tank full.
  27. Replies
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    Yes it is cooling the actual water that is used...

    Yes it is cooling the actual water that is used for the cement. Yes, it does have a strainer. I should open that the first thing when i get back there. I will.
    Question: As a strainer plugs; what...
  28. Replies
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    Jayguy: Why do you say "that explains the...

    Jayguy: Why do you say "that explains the approach?"
    I was hoping to get some numbers in my head to go back with. That approach is high for these brazed plate heat exchangers from my reading, but...
  29. Replies
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    Trane chiller low suction.

    Trane, 60 ton, CGAFC604A10000E000... Both circuits go off on low pressure as the water temperature gets closer to set-point.
    This chillers cools a 20,000 gal tank of water that is used for making...
  30. Thread: Liebert System4

    by mccann
    Replies
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    825

    What is a system 4? I have all the training...

    What is a system 4? I have all the training manuals for Liebert and I don't see it. Do you have a model #?
  31. Replies
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    @hvac69. I think you are right. Alas, I was...

    @hvac69. I think you are right. Alas, I was hoping I could change the output to analog. I do not see clear instructions on the web anywhere. I have already called in the "control company" to come...
  32. Replies
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    Belimo to controller change output

    I am looking for instructions on how to change the output of a controller.
    I have a Automated Logic controller ZN341v+ connected to a Belimo TR24-SR-T US for a reheat valve on a VAV. On a call...
  33. Thread: Hot loop

    by mccann
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    Thanks. Wow, just water going around and around...

    Thanks. Wow, just water going around and around in the pipe makes so much heat. Fascinating.
    Yes, the pump should be off, but apparently some nimrod bypassed the bad contactor and never followed...
  34. Thread: Hot loop

    by mccann
    Replies
    8
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    721

    Hot loop

    A small chilled water loop is 130*f.
    The chiller is off. The 3-way valve by the one air handler is in bypass; so no water is going through the air handler. The chilled water pump is jumped out and...
  35. Replies
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    369

    They look like standard temperature probes that...

    They look like standard temperature probes that you might strap to a pipe or hang in a duct. They do not have mounting hardware, just the little probe. We would have to replace them all. The plans...
  36. Replies
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    369

    Room sensor location

    I have a building with 2 Carrier boxcar units and about 12 VAV boxes each. The room sensors are in the return air registers. It does not control well, constant complaints. Different guys have tried...
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    Thanks, I think you are right. I will keep...

    Thanks, I think you are right.
    I will keep doing what I do and wait for the Singularity.
  38. Replies
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    I don't disagree with you. (Rant) I came from...

    I don't disagree with you.
    (Rant) I came from the supermarket world (20+ years). We worked with the high level control guys all the time and I have great respect for them. I don't want to mess with...
  39. Replies
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    That looks nice. Things are advancing...

    That looks nice. Things are advancing exponentially. I hate to spend a 10,000 hours and dollars to learn all the old junk. I think I will leave that to the specialist. Everything will eventually be...
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    yep, I'm not a controls guy

    yep, I'm not a controls guy
  41. Replies
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    1,009

    Not a controls guy, but

    I will never be a "controls guy." If you read the Controls section on HVAV-TALK, it looks like they're speaking Greek. I have respect for their ability and type of mind. However, we in the commercial...
  42. Replies
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    2,785

    Wow. Some systems are so bad. Get some pictures....

    Wow. Some systems are so bad. Get some pictures. Years later you'll look and say, oh yes, that POS; found a beer can in the oil separator.
  43. Replies
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    2,785

    The large oil separator should be fine. It is the...

    The large oil separator should be fine. It is the drop in velocity of the hot gas the drops out most of the oil from the refrigerant, so big is better. The helical style work great. The problem with...
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    New Carrier tripping VFD

    The VFD to the indoor blower has tripped a few times on over-current fault. It would run a couple days then be tripped.
    The unit is running in high speed fan, 60 Hz, because it is in economizer...
  45. Thread: Noisy duct

    by mccann
    Replies
    20
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    1,208

    Balancing damper screw loose?

    Balancing damper screw loose?
  46. Thread: Liebert AC4

    by mccann
    Replies
    2
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    619

    On Lieberts, you need to always shut the unit off...

    On Lieberts, you need to always shut the unit off with the off switch before killing power or it creates a power fail alarm. To reset it you need to power it off correctly again with the off switch...
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    Why don't vacuum pumps have a check valve?

    Why don't vacuum pumps have a check valve?
  48. Replies
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    3,452

    The solid wires should be pre-twisted together...

    The solid wires should be pre-twisted together with linemen's pliers before putting the stranded to it.
    If putting stranded to a solid or group or solids, strip the stranded longer so the end sticks...
  49. Thread: A/C Renew

    by mccann
    Replies
    31
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    4,272

    We just had the same thing happen on a new...

    We just had the same thing happen on a new Liebert Minimate. After 24 hours it started running great. Suction went from 20# to 65#.
  50. Replies
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    Lieberts now come with 407c in them. Many with...

    Lieberts now come with 407c in them. Many with the same R-22 compressors they always had. There's a small difference in settings but no big deal. I do not know if Liebert did a bunch of research and...
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