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  1. Replies
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    I think this goes back to the comparing of gate...

    I think this goes back to the comparing of gate valves and globe valves where gate valves were designed to be full open or full shut to prevent wire draw at the bottom of the valve gate while a...
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    That seems to be a typical complaint of ceiling...

    That seems to be a typical complaint of ceiling mounted diffusers. A few people get cold since the air is blowing right over thier desk.

    Cheapest option might be to have your HVAC contractor look...
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    I aggree that globe valves may often allow for a...

    I aggree that globe valves may often allow for a higher Cv rating, but I would disagree on the linear aspect. I would rather have a ball valve such as a Belimo CCV. If you are in the 4"+ sizes,...
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    The theory is you will exhaust more air than you...

    The theory is you will exhaust more air than you are bringing in. Thus you get the negative pressure. You should be able to download some resource information at Phoenix Controls as they are known...
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    Well, FYI - Rechecked the heat exchanger, looked...

    Well, FYI - Rechecked the heat exchanger, looked for soot, didn't find anything. Replaced the board - it has now been running for 3 days w/o a callback (used to trip within 24 hours) so I think that...
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    The other system with the 20 heat pumps may have...

    The other system with the 20 heat pumps may have a warmer loop just because with more heat pumps, there is a stronger possibility that some heat pumps are cooling while others are heating. The...
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    However, you can also buy a VAV box damper...

    However, you can also buy a VAV box damper actuator with a 3-5 psi operating range and a large damper actuator that has the same 3-5 psi operating range. 2 different torque ratings, but spring range...
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    The spring range has little to do with the actual...

    The spring range has little to do with the actual stem force. Instead it is usually used for varying the control range. Example... you want to control both a chilled water valve and a hot water...
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    I do control work at a local jail. One thing...

    I do control work at a local jail. One thing that we noticed right away is that the control room where the jailers monitored everything was on the same AHU as the jail cells. They ended up changing...
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    This website has some free education online...

    This website has some free education online classes. Not sure how good they are as I haven't found the time to check into it yet.

    http://aboutlightingcontrols.org/Education_Express/welcome.php
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    Could calculate approximate tonnage based on temp...

    Could calculate approximate tonnage based on temp drop across chiller. If design TD is 14 deg, 7 deg = 50%. We do something similair with a chiller plant w/ 3-950 ton Yorks. There we calculate...
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    I've had MUA burners that had the burner orfices...

    I've had MUA burners that had the burner orfices rust over. I would have to take a drill bit and run them into the burner to clean them out again. If they did light up, I would notice that all of...
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    Yeah, I thought of that. I couldn't see any...

    Yeah, I thought of that. I couldn't see any damage to the wires. I did lots of wiggling and such on all the wires and terminals to see if I could get it to act up.
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    No, not really. just the normal 5-10 mph. We've...

    No, not really. just the normal 5-10 mph. We've certainly had much more wind in the past and so I don't think that is the issue.
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    tubes look good. Motor was the same one I pulled...

    tubes look good. Motor was the same one I pulled out - combustion wheel looks good. I didn't actually put a probe up there by the roll-out switch, but after running for 15 min, it still felt like...
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    Carrier RTU Rool-out Switch Lockouts

    Hi All.
    I have a customer that has a carrier unit that has got me confused. Unit is a Carrier RTU, model 48TFE012 series 611. Serial # 1809G650436. I go out there because it isn't heating. When...
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    Thank you!

    Thank you!
  18. Replies
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    We have 2 boilers at a hospital with them. If...

    We have 2 boilers at a hospital with them. If they are set up correctly, they will help your fuel efficiency and if you switch from gas-oil, you can set different parameters for each fuel so no more...
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    could be the combustion blower blades are rusted...

    could be the combustion blower blades are rusted and it is falling apart once you turn it on. I am not sure about the trane furnace but I have had Carrier units that sound like that when they rust...
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    Trane Model Number question

    I was looking at a Trane BTR724E100AO condensing unit. I believe this is a 2 ton unit but can anyone verify that for me?
  21. Once you get access to the ALC website, use the...

    Once you get access to the ALC website, use the discussion forums and don't be afraid to ask questions. Several guys on there are very knowledgable and are usually very helpful. No question is...
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    Discussed this with Trane Tech support. He said...

    Discussed this with Trane Tech support. He said the check valve in the compressor that is shutting off is the problem. Said the check valve is leaking and that is causing the compressor to rotate...
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    Were you checking the blower amps with the blower...

    Were you checking the blower amps with the blower door open or closed? If open, blower would be pulling more amps than with closed.
    I've never worked on a Bryant RTU so I assume it is a direct...
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    maybe the power browned out for a while and the...

    maybe the power browned out for a while and the 24V dropped and so they sat and tried to pull the contactors in but couldn't and just burned up?

    Just guessing though.
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    Head pressure bouncing, causes loud noise

    Had a call on an A/C unit at a library today. About every 10 minutes, a loud noise is heard for about 5-10 seconds. Sounds like a condenser fan motor that has the bearings going out and squealing...
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