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-   -   Alternator and belt (https://vansairforce.net/community/showthread.php?t=157178)

Plummit 01-24-2018 08:44 AM

Alternator and belt
 
BPE IO540. I've got the prop off so I will replace the alternator and belt. The alternator spontaneously trips the 5 amp breaker for the field, usually when things like landing lights or other electrical switches are turned OFF. Any opinion on where to buy a replacement? I want new not rebuilt.

Also, the belt has 15375 and 422 stamped on it. There is little wear but I have 400 hours on the engine so I will replace it too. Is there a brand that is preferred?

-Marc

Mike S 01-24-2018 08:55 AM

Before spending the $$ for a new alternator, check the regulator-------assuming you have an external regulator.

B and C is a good source for these parts.

I used a belt from NAPA when I changed mine.

Also, thinking about the breaker tripping when you turn off a high load--------ground issues come to mind, also if you have a "crowbar" circuit it may be part of the problem, they are extremely sensitive.

airguy 01-24-2018 09:41 AM

Also - a 5 amp breaker for the field may be a bit light - many builders use a 7.5 amp to avoid nuisance trips. That doesn't explain it tripping when loads are turned OFF however. Do you have a crowbar overvoltage device installed? If so, then I would start to suspect the regulator as mentioned above.

Plummit 01-24-2018 11:51 AM

Built-in regulator and the Plane Power web site says my model, the AL12-E170C uses the "crowbar" device. I changed the breaker to rule out a weak unit. 5 Amp is the recommended size, but I thought about going to a larger breaker. The only thing that scares me is it sure looks like light wire going to the breaker. The $500 AS charges is nothing compared to the prop! :eek:

-Marc

alpinelakespilot2000 01-24-2018 12:10 PM

Your issues sound like the very common Plane Power failure modes that have been well documented here. You might consider an alternative. Lots of reading here on VAF, but here's one:
http://www.vansairforce.com/communit...liability+poll

Gates brand belts from your autoparts store are generally appropriate and, if I recall correctly, are what Van's recommended in their FWF kits.

Plummit 01-24-2018 01:58 PM

Interesting poll. I noted that several respondents indicated no problem with Plane Power, but it does seem that B&C is regarded as "better".

So here's a little more info: When I bought my RV with 150 hours on the hobbs, the builder told me (and I experienced) that if the engine kicked back during starts, the circuit breaker would trip if the engine turned "backwards". I timed the mags, which were a a little off and eliminated the kickback. Still, the breaker would trip on occasion. At some point I realized that it was tripping when things were shut off. I would flip the flap switch up to retract the flaps and as soon as the motor stopped the breaker would sometimes, but not always, trip. Other times I would clear the runway and do my post landing check. Sometimes, but not always, the breaker would trip when I turned the landing lights off. Lately it seems that it is more frequent, but again, not always.

I've tried different things like have the rpm up a little higher when I turned stuff off, but nothing seemed repeatable. One day the breaker tripped when I did a mag check! I have 2 Bendix mags, there is no way they should make the Alt. breaker trip!

I'll see what the new alternator does and post the results, but it will probable be 3 weeks before my prop is back.

~Marc

lr172 01-25-2018 10:19 AM

My first step would be to replace the breaker with a 7.5A. I started with a 5A breaker and it would trip whenever the alternator was putting out more than 30+ amps. Breakers can also be defective and trip at lower than rated amperage. The CB or the voltage regulator is more likely than the alternator, given the symptoms you describe. Do you have an external VR? If so, I would replace that as well.

I am not a fan of the planepower alternator. I have read about way too many problems with it. I use an ND alternator ($25) and it has been without issue for 500 hours.

Larry

bret 01-25-2018 03:53 PM

I could be wrong, but isn't the design of the crowbar to trip that 5 amp CB that feeds the field if there is an overvoltage problem? regulator wacko? :rolleyes:

BobTurner 01-25-2018 05:43 PM

You said the engine kicked back, more than once.These events have been known to break gear teeth, so I can?t imagine they?re good for the alternator either. I find it hard to believe a small timing error was the cause; more likely a non-retarded mag is hot.

Plummit 01-25-2018 08:07 PM

So I called Plane Power and spoke with a guy named Allen about the CB tripping when I turn stuff off. Allen thinks that there may indeed be a voltage spike when I shed load. He recommended that I try a slo-blow CB.

I called Stein and tried to order one and he doesn't carry such a thing. Moreover, he thinks that would probably be masking the real problem. He suggested I go back to Plane Power and try to get them to repair the alternator.

I called Allen back and hes says no dice, it's out of warranty. Fair enough, I ask him how much to overhaul it. They don't do that, The fix is to buy a new unit. Spruce is out of stock but A.E.R.O. will sell me one for $531.54. A few credit card numbers later and it's on the way. It's been an interesting morning.

-Marc


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