BDPetersen Posted June 22, 2016 Report Posted June 22, 2016 Raring back to install an Interav/Alcor alternator conversion. It references a placard to be installed near the field switch by part # (OCR-12A-6) but not having said placard, I am wondering what the exact verbiage might be. Anyone? (I know, Plane Power is better, but you work with what you have.) Quote
N601RX Posted June 22, 2016 Report Posted June 22, 2016 I can look and see later this week. The interav alternator seems to be a good unit, if you have problems with the regulator or overvoltage relay the planepower regulator is a legal replacement if you have the interav STC and much cheaper also. Quote
BDPetersen Posted June 22, 2016 Author Report Posted June 22, 2016 Thanks. I suppose the placard is on (or supposed to be) similar installations on other aircraft on the field. I'll stay tuned. Quote
BDPetersen Posted June 22, 2016 Author Report Posted June 22, 2016 I'm also curious how the field switch is handled in other installations. On the original generator setup, the field is switched by the master switch rather than a separate switch. I think the STC install instructions ok using the existing switch setup, but I would think a separate switch would be advantageous. I recall on older types that an over voltage trip was reset by turning the master switch off then on, in lieu of having an alternator switch to accomplish this. Quote
Andy95W Posted June 22, 2016 Report Posted June 22, 2016 The original switch can be used if it is a double-pole switch. I agree with you, BD, that having the two seperated is a better idea. Both of my M20Cs had the Interav conversion (great mod, BTW IMO- even better with the the PlanePower voltage regulator). My first one had the combined switch. I had an over voltage relay problem so to reset it I had to switch off the master switch- not fun to do in flight. My current C has a separate switch and I like the ability to control the alternator myself. Additionally, the VR does draw a small amount of current when it is on, so if I need to have the master switch on for any period of time, I know my current draw is as low as it can be. Quote
carusoam Posted June 22, 2016 Report Posted June 22, 2016 Having the independent switch allows the alternator to come online after engine start-up and before electronic instruments are turned on... Two good reasons... Best regards, -a- Quote
mike20papa Posted June 22, 2016 Report Posted June 22, 2016 I have this conversion too and with two separate switches on the "split master" one controls the alt field, the other the battery master contactor. The STC lists a "don't" that says never to open the battery switch when the alternator is running. I don't have this "placard" on my panel, but rather in my head..like don't engage the starter when the engine is running, don't confuse engine controls while operating & don't imagine there's fuel in the tank when there isn't. 1 Quote
BDPetersen Posted June 24, 2016 Author Report Posted June 24, 2016 Sigh. A new wrinkle in this conversion. Pulley/belt width mismatch. Pulley and belt on the flywheel which drove the generator is like a 1/2" width while the alternator pulley is on the order of 3/8". Looking for a pulley swap for the alternator, but so far have stymied everyone from local shops to Aerotech in Louisville. Plane Power uses a pulley capable of using either belt width. Anybody have a solution? Quote
carusoam Posted June 25, 2016 Report Posted June 25, 2016 Had this problem with a car once. Ended up walking some distance... In That case the alternator had the wrong pulley size and the belt broke. The remnants snagged and broke the water pump's belt.... The day just got longer... too wide risks the belt shredding. too narrow risks the belt slipping. wrong diameter risks over or under voltage...(?) and the ability to adjust belt tension may be limited... Definitely get the right pulley to match the belt exactly... Best regards, -a- Quote
BDPetersen Posted June 25, 2016 Author Report Posted June 25, 2016 Inasmuch as my bottom cowl is off and the generator is removed and much of my Mooney is strewn across the hangar floor, it is summer and no time to go tilt at windmills on a parts quest. So I ordered a Plane Power conversion. (I should teach a class on rationalization skills.) So if anyone has need for an Interav setup, it's available. 1 Quote
1524J Posted June 25, 2016 Report Posted June 25, 2016 10 hours ago, BDPetersen said: Inasmuch as my bottom cowl is off and the generator is removed and much of my Mooney is strewn across the hangar floor, it is summer and no time to go tilt at windmills on a parts quest. So I ordered a Plane Power conversion. (I should teach a class on rationalization skills.) So if anyone has need for an Interav setup, it's available. I think most of us who own an airplane could teach a class on rationalization skills....or we could face reality and realize we might be a bit irrational....at least when it comes to planes. Quote
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