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  1. #1
    Join Date
    Jul 2007
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    New Jersey
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    3,031

    Do you think its the heat?

    I do hvac in a steel mill. Our caster section has a torch pulpit. There are 2 package 3 ton Trane units on the roof of the pulpit. Its a new pulpit and the units are less than a year old. the engineer of this project never bothered to ask for our opinion on anything regarding the sizing or location etc of the system to use. The roof of the booth is about 30' from the billet cooling bed. Even on a cool day, the ambient temp in that area reaches 140°f atleast. Inside the booth, when the a/cs arent on, you cant even touch the walls. The plastic covering on the ceiling lights all melts off...THAT HOT.

    In less than 6 months we went through 3 blower motors, and 5 run caps.

    All from wires melting.

    When they ask me why this keeps happening??

    Is it feasable to simply say..."Thats easy, just like I said from the start when you didnt ask me my opinion..Because ITS TOO F***** HOT UP THERE"
    “If I have seen further than others, it is by standing upon the shoulders of giants.” ~ Sir Isaac Newton


    I'm learning all the time, the tombstone will be my diploma!!!


    Did you ever stop to think, and forget to start again?

  2. #2
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    145

    yup

    We had one in a refinery same issues had to install water packs on condensor
    problem went away (btw 140 was a cool day) and amazing enough a compressor lasted more than 2yrs go figure
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  3. #3
    Join Date
    Jul 2007
    Location
    New Jersey
    Posts
    3,031
    Sorry i didnt mention. its a water cooled package unit. Its the indoor blower motor that burns up.
    “If I have seen further than others, it is by standing upon the shoulders of giants.” ~ Sir Isaac Newton


    I'm learning all the time, the tombstone will be my diploma!!!


    Did you ever stop to think, and forget to start again?

  4. #4
    Join Date
    Jul 2011
    Location
    East coast USA
    Posts
    1,000
    Quote Originally Posted by Tommy1010 View Post
    I do hvac in a steel mill. Our caster section has a torch pulpit. There are 2 package 3 ton Trane units on the roof of the pulpit. Its a new pulpit and the units are less than a year old. the engineer of this project never bothered to ask for our opinion on anything regarding the sizing or location etc of the system to use. The roof of the booth is about 30' from the billet cooling bed. Even on a cool day, the ambient temp in that area reaches 140°f atleast. Inside the booth, when the a/cs arent on, you cant even touch the walls. The plastic covering on the ceiling lights all melts off...THAT HOT.

    In less than 6 months we went through 3 blower motors, and 5 run caps.

    All from wires melting.

    When they ask me why this keeps happening??

    Is it feasable to simply say..."Thats easy, just like I said from the start when you didnt ask me my opinion..Because ITS TOO F***** HOT UP THERE"
    YUP...its hot..it amazes me when no one ask the onsite personal their opinion,
    and that's what you get. did they duct the supply and return down? the other issue is they may have created stratification. I would hand it back over to the engineer who designed it and tell them it not working and make them deal with it. I hope they did their home work before they pop those up there!

  5. #5
    Join Date
    Jul 2007
    Location
    New Jersey
    Posts
    3,031
    When I did a quick version of load calc for that room.....without even taking into account the people and equipment inside the room...just off the ambient temp outside in the mill...its asking for a 10ton system. Instead they put 2 seperate 3 ton units and ran it as a lead/lag set up.....??? and the duct work forget about it....

    I told'em right from the start when i saw it...they shouldve put an indoor upright water cooled unit inside the room. The dirt in the air combined with the heat....is gonna be a nightmare....

    Oh yeah this is the kicker....as hot as it is up there....the 2 units are friggin heat pumps AND back up electric heat?????? WUT THE F****

    Motors are burning out and from the heat on units that you purchased with more heating than cooling BTUs....

    NICE
    “If I have seen further than others, it is by standing upon the shoulders of giants.” ~ Sir Isaac Newton


    I'm learning all the time, the tombstone will be my diploma!!!


    Did you ever stop to think, and forget to start again?

  6. #6
    Join Date
    Nov 2006
    Location
    Athens, Ohio
    Posts
    2,072
    When the revolution comes the engineers will be the first ones up against the wall.

    Wait, the lawyers are first, then the politicians, THEN the engineers.

  7. #7
    Join Date
    Jul 2011
    Location
    East coast USA
    Posts
    1,000
    Quote Originally Posted by Tommy1010 View Post
    When I did a quick version of load calc for that room.....without even taking into account the people and equipment inside the room...just off the ambient temp outside in the mill...its asking for a 10ton system. Instead they put 2 seperate 3 ton units and ran it as a lead/lag set up.....??? and the duct work forget about it....

    I told'em right from the start when i saw it...they shouldve put an indoor upright water cooled unit inside the room. The dirt in the air combined with the heat....is gonna be a nightmare....

    Oh yeah this is the kicker....as hot as it is up there....the 2 units are friggin heat pumps AND back up electric heat?????? WUT THE F****

    Motors are burning out and from the heat on units that you purchased with more heating than cooling BTUs....

    NICE
    I hear ya but I cant imagine why they chose RTUs to cool or ventilate this area. There is no easy way to maintain comfort levels in the whole place under those conditions. Not knowing your set up, but spot exhausting where the most heat is produced would help, good rooftop exhaust with gravity intake dampers would help during the colder months. and when its hot outside a floor mounted unit water cooled or even a swamp cooler would of been better than what you have. good luck on this one

  8. #8
    Join Date
    Jul 2007
    Location
    New Jersey
    Posts
    3,031
    Well how bout that..check the 1st post date of this thread...another cap just blew up.
    Its 115°f on the rooftop!!!!!. Supply voltage 479v thats fine. Started blower motor back up with new cap, its rated at 1.7...drawing 3A ..???? Dam near double

    On the last motor we changed out...you couldnt turn the shaft and it was hot as hell. As it cooled down it began to spin again,

    Im goin with the heat and expansion theory on this as the culprit for all these cap and motor issues

    . Any yays or nays?
    “If I have seen further than others, it is by standing upon the shoulders of giants.” ~ Sir Isaac Newton


    I'm learning all the time, the tombstone will be my diploma!!!


    Did you ever stop to think, and forget to start again?

  9. #9
    Join Date
    Feb 2010
    Location
    In a boiler room
    Posts
    7,223
    100% outdoor air units would be better than returning all that hot air!

    Like someone said, exhaust the hot air, don't try to condition it.

  10. #10
    Join Date
    Jul 2007
    Location
    New Jersey
    Posts
    3,031
    Quote Originally Posted by chuckcrj View Post
    100% outdoor air units would be better than returning all that hot air!

    Like someone said, exhaust the hot air, don't try to condition it.
    or just simply put an indoor upright unit in the room like i said from day 1
    “If I have seen further than others, it is by standing upon the shoulders of giants.” ~ Sir Isaac Newton


    I'm learning all the time, the tombstone will be my diploma!!!


    Did you ever stop to think, and forget to start again?

  11. #11
    Join Date
    May 2007
    Location
    Wildomar Ca
    Posts
    221
    Quote Originally Posted by chuckcrj View Post
    100% outdoor air units would be better than returning all that hot air!

    Like someone said, exhaust the hot air, don't try to condition it.
    I have to agree there is know way you are going to condition that space.
    I think a hydronic system would have been better for this situation.
    A chilled water system would be much more forgiving.
    Also an air handler with the motor externally mounted so it would not be xposed to those high. Temps.
    Why were heat pumps used.?
    Seems like you would never need heat.
    Some of these engineers just don't get it they have never worked in the field and and every thing looks good on paper.but in real life it does not work.
    Joe

  12. #12
    Join Date
    Apr 2012
    Location
    So. Fl.
    Posts
    57
    I've heard that in Europe, b4 you can apply for license asan engineer. You must work in the field for one or two years, that is with a recommendation from the employer, then you can take the certification(license). Seems like that's what we should here in the united states.

  13. #13
    Join Date
    Apr 2012
    Posts
    15
    Engineers are like teenagers you don't have to tell them anything cause they already know it all.

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