Pump Location?
10-08-2004 | 10:16 AM
#1
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From: Jackson,
MS
Pump Location?
About how far away from the engine should you locate your pump?
I scratch built a turbine trainer. My pump is located about four inches from the engine. Is this too close to the engine? I am getting erratic rpm readings causing my engine to overheat and flame out. I think the pump is interferring with the hall sensor.
Thanks for any help.
Hal
I scratch built a turbine trainer. My pump is located about four inches from the engine. Is this too close to the engine? I am getting erratic rpm readings causing my engine to overheat and flame out. I think the pump is interferring with the hall sensor.
Thanks for any help.
Hal
10-08-2004 | 01:11 PM
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From: aberdeen, UNITED KINGDOM
RE: Pump Location?
HI,
YOUR PUMP SHOULD HAVE SUPRESSION CAPACITORS FITTED TO IT, (STANDARD PRACTICE) TO REDUCE "NOISE" AND IT SHOULD BE PLACED CLOSE TO YOUR FUEL TANK AND THE DISTANCE FROM THE PUMP TO YOUR TURBINE WILL NOT MATTER. IF YOUR TURBINE IS FLAMING OUT, THEN YOU MUST ENSURE YOU ARE NOT GETTING AIR INTO THE FUEL FEED LINE GOING TO THE TURBINE - THIS CAN BE PREVENTED BY FITTING A UAT OR A HOPPER TANK.
IF YOU ARE GETTING ERRATIC RUNNING, THEN YOU MUST ALSO REMEMBER TO KEEP THE TURBINE ECU SEPERATED FROM YOUR RADIO RECEIVER TO AVOID INTERFERENCE - THIS APPLIES TO THE RX AND ECU BATTERY PACKS.
I THINK A HALL SENSOR RELIES ON MAGNETIC FEILD CHANGES, TO DETERMINE SHAFT SPEED, SO YOUR PUMP COULD BE INTERFERING WITH IT AS A PUMP DOES HAVE MAGNETS INSIDE IT BUT I AM JUST GUESSING.
duthie.
YOUR PUMP SHOULD HAVE SUPRESSION CAPACITORS FITTED TO IT, (STANDARD PRACTICE) TO REDUCE "NOISE" AND IT SHOULD BE PLACED CLOSE TO YOUR FUEL TANK AND THE DISTANCE FROM THE PUMP TO YOUR TURBINE WILL NOT MATTER. IF YOUR TURBINE IS FLAMING OUT, THEN YOU MUST ENSURE YOU ARE NOT GETTING AIR INTO THE FUEL FEED LINE GOING TO THE TURBINE - THIS CAN BE PREVENTED BY FITTING A UAT OR A HOPPER TANK.
IF YOU ARE GETTING ERRATIC RUNNING, THEN YOU MUST ALSO REMEMBER TO KEEP THE TURBINE ECU SEPERATED FROM YOUR RADIO RECEIVER TO AVOID INTERFERENCE - THIS APPLIES TO THE RX AND ECU BATTERY PACKS.
I THINK A HALL SENSOR RELIES ON MAGNETIC FEILD CHANGES, TO DETERMINE SHAFT SPEED, SO YOUR PUMP COULD BE INTERFERING WITH IT AS A PUMP DOES HAVE MAGNETS INSIDE IT BUT I AM JUST GUESSING.
duthie.
10-08-2004 | 01:13 PM
#3
RE: Pump Location?
Hal,
Whilst I would not rule out the pump being the cause of this, I have never heard of it. Hall sensor are suseptible to interference if cables from servos etc are laid close to the hall sensor lead and this is a common source of trouble. Of course if the pump cables come close to the sensor cables, or if the sensor cable come close to the pump itself, then problems will ensue.
Planning the installation so that all the elements fit, with due cogniscience of the necessary seperations required, and ending up with the model balancing on the CG is the hardest part of building jets.
One more thing, sensor have been known to crack if the bolts are overtightened. A friend had about a 100 30 second flights untl we found this was the cause. He had changed just about everything else in the model over a period of some months, without success.
I hope this helps,
Regards,
John.
Whilst I would not rule out the pump being the cause of this, I have never heard of it. Hall sensor are suseptible to interference if cables from servos etc are laid close to the hall sensor lead and this is a common source of trouble. Of course if the pump cables come close to the sensor cables, or if the sensor cable come close to the pump itself, then problems will ensue.
Planning the installation so that all the elements fit, with due cogniscience of the necessary seperations required, and ending up with the model balancing on the CG is the hardest part of building jets.
One more thing, sensor have been known to crack if the bolts are overtightened. A friend had about a 100 30 second flights untl we found this was the cause. He had changed just about everything else in the model over a period of some months, without success.
I hope this helps,
Regards,
John.
