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DIESEL MOTORS STARTING SYSTEMS

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Engels

Electrical
May 19, 2002
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I need buy a 850 HP water pump drived by diesel motor, my client prefer electric DC motors to starts the motor, but my experience indicates, in this case, pneumatic starting is more usual, safety, economical and realiable. I don't find suggestions about it, on ANSI ou IEC etc. What is better?
 
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I assume that this diesel driven pump is installed at a remote location where there is no electric power supply from a grid.

I think electric starting with larger diesel gen sets is used mostly on packaged gen sets or stand by ones and seldom on big stationary gen sets.Whichever, the electric mode of starting comes in handy and ecomomic as it doesn't need the various air piping required to interconnect the engine/the air bottle and the controls.You also need a small diesel generator and a compressor (to fill up the tanks on lowering of the bottle pressure)which calls for some type of fuel storage facility and a regular flow of fuel.You may also need to take care the maintenance needs of this generator. You may also need this generator along with a charger for charging the starting battery if you opt for electric starting.Don't forget in your comparisons that your batteries need to be changed every 3-5 years.
 
depending on the installation... the diesel manufacturer should be able to recommend a suitable solution...
the DC starting motor is usually used in these small engines compared to the pneumatic start used in large (slow) marine engines.
the advantage of the dc start is that it allows a quick re-start in case the 1st fails... while the pneumatic requires recharging the accumulator.
if the pump is in a remote location the batteries required for the DC start require less maintenance than the pneumatic start... but they also require that the environment is controlled to avoid damage during long stand-by periods.
HTH

saludos.
a.
 
Electric and pneumatic starting systems are both potentially good choices depending on the particular needs of the application. If you would provide more information, better advice could be available to you.

In general, I would be most inclined to favor an electric starting system for an engine in this size range for practicality and cost, but site conditions must weigh very heavily in the actual selection.
 
Unless you are going to use this pump in a location where there is a dependable source of compressed air, I would recommend the electric start. Electric starting systems have their own peculiarities, and problems, but the electric systems are easier to recover and bring back up to starting voltage. Hauling a new battery to start the pump is easier than hauling a compressor. Batteries are affected by temperature, but so are compressed air systems.

I have seen both air hoses and electrical lines strung out long distances across expansive parking areas for air start vehicles which would not "bust right off" in sub zero weather, while merely a jump start from a pick up truck would have sufficed for an electric start vehicle.

I have seen air started, "black start" (air started diesel engine cranked) gas turbine black start Frame 5 size peaking units which could not be "black started" until a portable compressor was located (from the water department, in the case of this municipal electric utility,) and hauled to the unit, and jury rigged, because the air system at the plant went down when the system went "black". (I put it in the black, while running tests, unfortunately)

rmw
 
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