harv-t2 Posted July 4, 2011 Share Posted July 4, 2011 we have a problemon an ac-130h that we have been unable to solve for a while. when you have any power source on but our atm generator the aux pump will come online fine, if the aux is already running the atm will run with no problem but if you have ATM online when you turn on aux pump it drops down to 350 htz and goes off line we have changed almost all components that apply. currently we are changing our aux pump relay due to our supervision the only thing that is strange is that we are getting 30 ampres higher than our other aircraft if anyone has any tricks that would help us please let me know Quote Link to comment Share on other sites More sharing options...
NATOPS1 Posted July 5, 2011 Share Posted July 5, 2011 "we are getting 30 ampres higher" Please explain your statement... 30 amps higher (draw) when you trun on the AUX pump? Do you "hear" the ATM (Gen) wind down? (or just see the frequency drop on the meter?) How long does the Gen take to "drop off line" once the freqs drop? (instant or does it take a few seconds?) Does this happen if you use both or just one of the AUX pump switches to turn on the AUX pump? Quote Link to comment Share on other sites More sharing options...
Ben Legere Posted July 5, 2011 Share Posted July 5, 2011 If your ATM drops down to 350hz you are not having an electrical problem. Run an engine and use that bleed air to run your ATM and see if the problem persists. If your ATM continues to go off line with bleed air from an engine the problem lies in your ATM itself(not the generator), if it goes away with an engine running you have a sticky load control valve that is allowing the ATM to drop off-line because it can't get enough bleed air to sustain full RPM. Good luck. If you can't run an engine at the time just watch the bleed air gage by the nav's table to see if it drops off when you turn the Aux pump on. It should stay steady and not move at all but if it moves even the slightest bit your load control valve is not opening up fast enough to keep up with your ATM. One more thing: We also had a problem with the ATM dropping off line with a load applied a few years back and found the ATM plug lodged in the cooling fan. Quote Link to comment Share on other sites More sharing options...
bischoffm Posted July 5, 2011 Share Posted July 5, 2011 You have changed the ATM right?? Quote Link to comment Share on other sites More sharing options...
crizeg721 Posted July 7, 2011 Share Posted July 7, 2011 R2 E&E troop Quote Link to comment Share on other sites More sharing options...
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