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 MintJulep 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. crisleon

    Does it Exist--Need a Battery to output 10A/18V over Long Time

    Maybe there is the method to recharge the battery - let's say the solar panel installed on the buoy anchored over this underwater system (wire connection probably is not to avoid however). It depends how deeply is to be sunken. Probably there are lighting buoys with independent supplying...
  2. crisleon

    Ckt Bkr is Tripping: Feeder for 40 HP Elevator.

    Sspeare: "Electrician has now adjusted the instantaneous trip on both CBs to 7X the breaker rating. We will see what happens". I am not sure if I understand you, however I can't abstain from the caution: it may be a mistake. To "see what happens" may be not proper strategy. Look: 7x rating = 7...
  3. crisleon

    Ckt Bkr is Tripping: Feeder for 40 HP Elevator.

    Do you know now which breaker was tripping first? I have no idea how to help you. CB#2 is crucial for the safety of your motor. CB#1 should trip later than CB#2, so the time setting here would have the desirable effect (if possible anyway to set anything on it). In my opinion the...
  4. crisleon

    Ckt Bkr is Tripping: Feeder for 40 HP Elevator.

    Well, "MOTOR CIRCUIT PROTECTOR" sounds quite good, similarly as SOLID STATE SOFT-START CONTROLLER. If this MCP is equipped with real protection of the motor, I may withdraw some my previous claims and reservations referring to the CB #2 (after getting your scheme and parameters maybe I'll be...
  5. crisleon

    Ckt Bkr is Tripping: Feeder for 40 HP Elevator.

    Well, I am not sure if I understand your note. However as far as I can understand I just try to advice you in your 3 questions and others. 1) You have to know which CB tripped, it is absolutely necessary for going farther. I can't understand this electrician who don't know which one tripped...
  6. crisleon

    the magnetising current

    No problem. I found that in my text above the last-but-one sentence should be correctly in such a way: "In addition I stated the similar question referring to the 2-nd harmonic and I answered "yes". A mistake may be a fatigue symptom. Regards CL
  7. crisleon

    the magnetising current

    Gunnar: "The first three answers to the OP were very much tongue-in-cheek". I can't agree with your opinion. My very first answer was absolutely serious. Question was "yes or no?" and my answer was "no". In addition I stated the similar question referring to the 3-rd harmonic and I answered...
  8. crisleon

    the magnetising current

    1. The magnetising current inrush in a transformer is "rich" in 3rd harmonic? yes or no? NO 2. The magnetising current inrush in a transformer is "rich" in 2nd harmonic? yes or no? YES
  9. crisleon

    11/33kv Line Route Design

    Do you think about geodesic measurements? I am not the surveyor, I can't help you. You may try with the www: http://en.wikipedia.org/wiki/Surveying and other professional sites, companies or persons. Regards
  10. crisleon

    Power consumption in the office building

    I thank everybody for your advice and information. Rafiq, don't hesitate to talk about such things as I consider. I am an experienced designer and I won't do such mistakes as you mentioned. I am in contact with people from the utility company and I know some data. I want to verify this...
  11. crisleon

    Power consumption in the office building

    If you suggest that 60-70 W/m2 is not bad I may say that I think just also about such a coefficient. Bluntly speaking I am afraid that I may make the mistake to undervalueting the toatal demanding power (the risk of the discredit). Regards.
  12. crisleon

    Power consumption in the office building

    RBulsara, thank you for your advice. Haven't you any own experience in this topic? I have some data, of course. Designers are likely here to do prior estimation at the higher level than it is in the real life (similarly, some guides and publications). However this is not so stupid because the...
  13. crisleon

    Calculations for cable size

    RBulsara, well, you are absolutely right. However please have a look at this case - you have cable-core-CSA=16mm2 and the current load 2*2A=4A in total. Are you really likely to check dimensioning of this cable on the condition of the withstanding of the total load? By the way, you should...
  14. crisleon

    Power consumption in the office building

    I would like to ask you about the real power consumption for the A-class office building. The problem is that we designers have to prepare the application to the grid operator here in Warsaw, Poland, for technical conditions for supply for such a high-rise tower of about 70,000 sq. meters...
  15. crisleon

    Calculations for cable size

    Are you asking for the formula for voltage drop? deltaU% = 200 * l * L * cos? / (gamma * A * U) [%] deltaU = 2 * l * L * cos? / (gamma * A ) [V] You have U=230V, I=4A, cos?=0,8 or 1,0 or something else (you probably know it) L=800m, gamma =57 [m/Ohm*mm2] for Cu or 33 for Al A=16mm2 For your...
  16. crisleon

    The mysterious tripping during transformer's energizing

    Gentelmen, 2,5MVA trafo (dry type Trihal) is protected by Sepam. It is completely new and was tested by the producer's representative (Schneider) and seems to be OK. We can't test it onece more now because it is still working (after the energizing problematic start we have no troubles with it)...
  17. crisleon

    The mysterious tripping during transformer's energizing

    Wcarter - certainly, these are 2 cables with 3 * single 150mm2-Alu cores, each one in XLPE insulation longitudinally sealed, with the copper 35mm2-shielding cores grounded on both ends of the line (and the common copper shielding core going back through the window of the Ferranti I0 transformer...
  18. crisleon

    Heat losses from large switchboards

    What total result have you obtained after your re-calculating? First calulations gave you about 170kW, how much have you got in the second estimation?
  19. crisleon

    The mysterious tripping during transformer's energizing

    Thank you for your suggestions, I have to investigate this case once more. Regards
  20. crisleon

    The mysterious tripping during transformer's energizing

    Hello, please consider and help me to solve my puzzle. All went well during first NO-load energizing of the 15kV/6kV 2,5MVA transformer via cable line (of L=400m, 3x150mm2 Alu, probably with inrush-current about 10*FLA, Sepam protection). However we got problem with the other loaded cable line...

Part and Inventory Search

Back
Top