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  1. cctdiag

    Turbine power - theory?

    Hi, Can anyone help and explain in 'laymans terms' why the power delivered to a turbine is proportional to: - i) the density of a fluid, and ii) the cube of the speed of a fluid. My question application is related to hydro-electric power generation. Many thanks cctdiag
  2. cctdiag

    ABB SACE E6 - racking out issue

    Zogzog, Thanks for that, I'll be back onto ABB tomorrow morning, not too impressed as they were told the breaker was still charged. Jeff
  3. cctdiag

    ABB SACE E6 - racking out issue

    Hi, Can anybody advise on a racking out issue that I have with two SACE E6 breakers? To insert the racking out handle a shutter has to be dropped to allow the handle to be engaged; a standard arrangement in many switches. According to the SACE manual this is achieved by pulling down on a small...
  4. cctdiag

    Incinerator noise control

    Hi Hiebs, At the moment this is a hypothetical question, with no sound levels to work to, I have to just accept the stack is noisy and needs silencing. I am being asked to specify any appropriate noise control method - the hypothetical stack is from an energy from waste incinerator. Thanks for...
  5. cctdiag

    Incinerator noise control

    Hi, I have been asked to investigate noise control methods for waste incinerator stacks. As this is not my field of speciality can anybody give me some ideas or know of any existing solutions to get me started. Thanks
  6. cctdiag

    Incinerator noise

    Hi, I have been asked to investigate noise control methods for waste incinerator stacks. As this is not my field of speciality can anybody give me some ideas or know of any existing solutions to get me started. Thanks Cctdiag.
  7. cctdiag

    Stack characteristics?

    Thanks 25362 for the much appreciated confirmation on velocity and expected m3 of flue gas. However is there a ideal flue gas temperature I should be looking for. This is for a hypothetical problem I have been set, I am comparing the pollution effects of an energy from waste plant (70m stack...
  8. cctdiag

    Stack characteristics?

    Hi, Knowing virtually nothing about combustion hopefull you guys maybe able to help? I am working on a dispersion model for NOx emission but I need to work out an effective stack height by using a Briggs equation. But I have no info' on flue gas temperature, gas volume being discharged or flue...
  9. cctdiag

    Low resistance??

    Hi, Many thanks for the input, I recently performed a 5min discharge test to the battery string, the suspect battery held up OK with no real drop off in voltage in comparison to the other cells? On checking the cell resistance a couple of days later, it had returned to around the expected...
  10. cctdiag

    Low resistance??

    Hi Can anybody advise on what would cause the internal resistance of a lead/acid 6V 3-cell battery to suddenly drop. The value has gone from 4 ohms down to 0.3 ohms over a period of 2 weeks. The voltage of the cell has remained constant at 6.58 volts. This is one battery of 64, all other...
  11. cctdiag

    Switch off A/C at altitude

    Hi Could anybody please explain why there is a sign at the top of Yosimite Pass which asks drivers to switch off their cars air conditioning. I am presuming it has something to do with the effect of air prssure at altitude which could damge the A/C unit - but not being fridge minded can...
  12. cctdiag

    Switch off A/C at altitude?

    Hi Could anybody please explain why there is a sign at the top of Yosimite Pass which asks drivers to switch off their cars air conditioning. I am presuming it has something to do with the effect of air prssure at altitude which could damge the A/C unit - but not being fridge minded can...
  13. cctdiag

    Icing under pressure?

    Gents I have a watermist fire extinguishing system which states 'Protect from freezing'. It has a water filled sensing line charged at about 50 psi, this in turn fires a bank of water filled cylinders at 200 psi. The installation is in an unheated generator room, so what I would like to know...
  14. cctdiag

    Transformer room ventilation

    Thanks for your responses, Stevenal thanks for your concern, Installation of gas extinguishing systems which discharge into a sealed area should also incorporate pressure relief dampers. The damper will open on initial discharge and close according to its closing design weight, this should...
  15. cctdiag

    Transformer room ventilation

    Hi Does anybody know if there is a requirement or guide (in UK)for ventilating transformer rooms? We have 2 x 1MW 11kv/415v ONAN tansformers in their own dedicated rooms, both have ventilation grilles in the entrance doors. I have been asked if they could be boarded up so to create a 'sealed'...
  16. cctdiag

    Tap changing?

    Gents Many thanks for the confirmation, i have passed this onto the the person who carried out the change. He did mention the Transformer did not like the switching action by the noise it made. I think the comment 'catastrophic' has hit home and a lesson been learned, he will not do this again...
  17. cctdiag

    Tap changing?

    Normally we tap change our 11000/415v transformers isolated (as recommended), however due to a high authority supply voltage we had to do a change on a transformer energised but with no load.(load supported via generators) Can anybody advise if this could of had a detrimental affect on the...
  18. cctdiag

    Battery Cell Oil?

    Hi Could any body explain the reason for the addition of cell oil found in Ni-Cad batteries. Thanks cctdiag
  19. cctdiag

    Condenser freezing up?

    Thank you all for yuor contributions, i will digest DeltaCascade's post before I go any further. But in the meantime I will get the gas charge checked again and carryout cleaning of the coils, as these seems to be common points made by most. cctdiag
  20. cctdiag

    Condenser freezing up?

    The unit in question is nearly 3 years old and has been giving us problems over the last two winters. The unit has been checked for low gas levels but is ok Jeff
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