Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. chunia

    Rope light and NEC

    Thanks, will look for UL lable
  2. chunia

    Rope light and NEC

    Hi, Is NEC considers plug-in rope light ( LEDs in clear tubing 50 ft long) as temporary installation? Rope installed inside, above drop-in ceiling. TIA
  3. chunia

    Liquid nitrogen to gas

    Quark, Thank you for spending your time to explain all details of the process to me. I do not want spend any more of everybody’s time on the issue. The answer is : To convert one gallon of liquid nitrogen to the gas at 70F and 100 psi takes 1235.5 Btus Again, thanks to everybody who helped me...
  4. chunia

    Liquid nitrogen to gas

    Thanks to everybody for the inputs. Warming the gas: Q= 1.08 X CFM X (t1-t2) 1 gal of liquid nitrogen = 93.11 cubic feet Q= 1.08 X 93.11 X (319+70) = 39117 Btu/gal of liquid or Btu/ 93.11 cfm of gas Latent heat of vaporization 86.6 Btu/lb = 583.5 Btu/gal Total: 39700 Btu/gal According to...
  5. chunia

    Liquid nitrogen to gas

    Yes, you are absolutely correct. Thanks. I saw the formula somewhere ( Btu for warming gas) just need to find it.
  6. chunia

    Liquid nitrogen to gas

    Unotec, It just for converging from liquid to gas. Now I need to warm up the gas from -319F to +70F at 100psi.
  7. chunia

    Liquid nitrogen to gas

    According to the table out of NIST webbook it takes 85 Btu to convert pound of liquid Nitrogen to gas (1 deg. delta) Am I correct?
  8. chunia

    Liquid nitrogen to gas

    Guys, Sorry for not getting back here sooner, just was busy with electrical problems. Thank you for pointing me to the right direction, Google is really good source of information, but I did not find an answer to my question. I will keep looking.
  9. chunia

    Liquid nitrogen to gas

    No, where I can find it? Thanks
  10. chunia

    Liquid nitrogen to gas

    95 to 100 psi Thanks
  11. chunia

    Liquid nitrogen to gas

    Hi, How to calculate how many BTUs it takes to convert one gallon of liquid nitrogen (LN2) into gas? We use heat exchanger with 280F hot water. Output gas temperature 70F TIA
  12. chunia

    Fluorescent ballast efficiency

    davidbeach, you are right. Light photon emitted by the bulb has energy, and this energy transfers to heat, when object absorbs light. For heat load calculation amount of heat produced by lamp-ballast combination equal to ballast wattage (IMHO).
  13. chunia

    Fluorescent ballast efficiency

    Gentlemen, thank you for answers I called tech.support at Universal ballasts (http://www.universalballast.com/productLines/ballast/line_fluor_elec.html) and they told me to calculate loses on the ballast use formula: Loses = Watts in – Total lamp wattage X Ballast factor If we will take...
  14. chunia

    Fluorescent ballast efficiency

    Senselessticker, Ballast Efficacy Factor (BEF) useed to compare two ballasts (AFAIK). Is it any way to get to efficiency from BEF?
  15. chunia

    Fluorescent ballast efficiency

    Hi, Does anybody know how to calculate efficiency for fluorescent ballast? I need it for room heat load calculations. TIA
  16. chunia

    15 kV J-box

    Gentlemen, Thank you for replies. Yes, I know about all problems associated with J-box configuration. I will be happy to install S&C Vista line-up, but money is an issue (and physical size of equipment). Original system (with 3 J-boxes 1in-3out)worked for last 35 years (indoor installation, no...
  17. chunia

    15 kV J-box

    Sorry, HighPotter... first time poster....:-) I am looking for metal J-box with copper buss work to distribute 15 kV within the building. J-box will be installed in HV room in the building. 3 phase 600A max. One incoming feed from switchgear will be distributed to 6 substations.
  18. chunia

    15 kV J-box

    Hi, I am looking for 15kV J-box on the net and coudn't locate any manufacturer. Please help if you know who makes them. TIA

Part and Inventory Search

Back
Top