bonzo Posted October 2, 2009 Share Posted October 2, 2009 Guys, What is the pressure between the speed controller on the ATM and the modulating valve telling the valve to open and close to keep the 43.000 RPM. We know that the pressure between the inline filter and the ATM speed controller is 50-55 PSI. Thanks in advance Bonzo Quote Link to comment Share on other sites More sharing options...
ArcticFox Posted October 2, 2009 Share Posted October 2, 2009 (edited) Are you asking about the speed sensing butterfly valve in the turbine inlet that prevents the ATM from over speeding? -Also I thought the ATM spins at 8000 RPM (6 pole gen needing to provide 115/200 @ 20KvA (30vA)). Does the turbine that drives the Generator spin at 43k rpm?? Jeez if so I never knew that. (but then again, I'm just a young'n). Makes sense would be easier to get the motor spinning and probably less load on the bleed air system. Edited October 2, 2009 by ArcticFox Quote Link to comment Share on other sites More sharing options...
OEO Posted October 3, 2009 Share Posted October 3, 2009 (edited) bonzo, There is no set pressure coming from the oil pump and controller assembly to the opening side of the modulating valve actuator. The amount of pressure leaving the controller assembly to the modulating valve actuator is that is need to over come the 50+/-5 psi and the spring tension on the closing side of actuator, to maintain the ATM turbine speed at 43K rpm. If the ATM turbine rpm speed drops, the controller assembly will supply pressure above the 50-55 psi to open the modulating valve to speed the ATM turbine back up to 43k rpm. Or if the ATM turbine speed goes over 43K rpm, the controller assembly will deliver less pressure than 50-55 psi to close the modulating valve to slow down ATM turbine. And the amount of pressure the controller assembly will put out to get the turbine to 43K rpm depends on the rate accelleration or decelleration of the ATM turbine at that moment. So the pressure leaving the controller assembly is veriable and is always change to maintain the turbine speed. My reference is the (OMMS) T.O. 49 General System from 2002 time frame when I was tech school instructor at Sheppard AFB. I hope this helps you and I hope I did not dumb this down too much. Owen Edited October 3, 2009 by OEO Quote Link to comment Share on other sites More sharing options...
bonzo Posted October 3, 2009 Author Share Posted October 3, 2009 Guys, Thanks for the info this really helps alot. Owen (OEO) had the right info I was looking for. Thanks Bonzo Quote Link to comment Share on other sites More sharing options...
ArcticFox Posted October 3, 2009 Share Posted October 3, 2009 Learn something new everyday with these planes. Quote Link to comment Share on other sites More sharing options...
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