---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 06/17/16: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:31 AM - Wrong email address - Re-send pls (Franz Fux) 2. 01:46 PM - Problem with starting (Alec Myers) 3. 01:58 PM - Re: Problem with starting (Kelly McMullen) 4. 02:19 PM - Re: Problem with starting (Alec Myers) 5. 02:33 PM - Re: Problem with starting (Justin Jones) 6. 02:36 PM - Re: Problem with starting (Justin Jones) 7. 02:53 PM - Re: Problem with starting () 8. 03:07 PM - Re: Problem with starting (Alec Myers) 9. 03:53 PM - Re: Problem with starting (David Lloyd) ________________________________ Message 1 _____________________________________ Time: 12:31:35 AM PST US From: "Franz Fux" Subject: AeroElectric-List: Wrong email address - Re-send pls I will no longer be checking franz@lastfrontierheli.com due to excessive and uncontrollable spam. Please re-send your email to my new address: franz.fux@lastfrontierheli.com and make a note of it for the future. Apologies for the inconvenience, Franz Fux Last Frontier Heliskiing - Go Beyond www.lastfrontierheli.com --- Head Office: PO Box 1237, Vernon, BC V1T 6N6, CANADA Tel: 250 558 7980 Fax: 250 558 7981 Reservations: 1-888-655-5566 ________________________________ Message 2 _____________________________________ Time: 01:46:22 PM PST US From: Alec Myers Subject: AeroElectric-List: Problem with starting Fresh on the heels of asking for help with the low bus voltage with the engine running in my C182, I now have an issue with intermittent cranking on start. Symptoms: About 5 times out of 10 turning the key switch to start elicits no prop movement. Not even a tiny bit. The other times the cranking is healthy. During a no-turn start, I can hear the starter contactor oscillate on/off at about 5Hz, the bus voltage drops to 6 volts or below, and after a few seconds the earth braid from the battery to the fuselage gets warm/hot to touch. Yesterday I had the alternator overhauled, and replaced: no change in behaviour. Sometimes it cranks well 10 times in a row, sometimes it fails to turn, 10 times in a row. After a few trial starts today the battery was dead. So I gave it an external charge 20A for an hour. The next start failed. The one after that was fine, then it went sulky and failed a few times. Twice in maybe 40 trial starts (been working on this at various times over two days now) the main (battery) contactor has remained shut and I have been unable to shut off the power by turning off the master switch. The second time this happened I gently tapped the battery contactor with a rubber tool and the contact was successfully broken. I have now replaced this contactor. I imagine this stuck-on behaviour is because the contact has tried to open due to low coil voltage and welded itself shut because of an overcurrent condition. Twice overall I have seen it enter this failure mode during cranking and while the prop is turning: the prop stops and bounces back against the cylinder compression, the bus voltage drops out and the contactor starts to buzz. This is all consistent with a dead short either in, or downstream of the starter contactor. I would be looking very hard at the starter motor, but I've already had this overhauled, new springs, brushes etc., just yesterday. Has anyone seen a failure like this in their experience? Anywhere else I could look? It's really a very simple circuit and it must be drawing several hundred amps somewhere... ________________________________ Message 3 _____________________________________ Time: 01:58:04 PM PST US Subject: Re: AeroElectric-List: Problem with starting From: Kelly McMullen Most likely your battery is on its last legs, or it has not achieved a full charge. After being charged, and sitting overnight, the battery resting voltage should be at least 12.7. If it is closer to 12.5, the battery is either weak or didn't get fully charged. You could do, or have done a capacity check. On 6/17/2016 1:44 PM, Alec Myers wrote: > > Fresh on the heels of asking for help with the low bus voltage with the engine running in my C182, I now have an issue with intermittent cranking on start. > > Symptoms: > > About 5 times out of 10 turning the key switch to start elicits no prop movement. Not even a tiny bit. The other times the cranking is healthy. > > During a no-turn start, I can hear the starter contactor oscillate on/off at about 5Hz, the bus voltage drops to 6 volts or below, and after a few seconds the earth braid from the battery to the fuselage gets warm/hot to touch. > > Yesterday I had the alternator overhauled, and replaced: no change in behaviour. Sometimes it cranks well 10 times in a row, sometimes it fails to turn, 10 times in a row. > > After a few trial starts today the battery was dead. So I gave it an external charge 20A for an hour. The next start failed. The one after that was fine, then it went sulky and failed a few times. > > Twice in maybe 40 trial starts (been working on this at various times over two days now) the main (battery) contactor has remained shut and I have been unable to shut off the power by turning off the master switch. The second time this happened I gently tapped the battery contactor with a rubber tool and the contact was successfully broken. I have now replaced this contactor. I imagine this stuck-on behaviour is because the contact has tried to open due to low coil voltage and welded itself shut because of an overcurrent condition. > > Twice overall I have seen it enter this failure mode during cranking and while the prop is turning: the prop stops and bounces back against the cylinder compression, the bus voltage drops out and the contactor starts to buzz. > > This is all consistent with a dead short either in, or downstream of the starter contactor. I would be looking very hard at the starter motor, but I've already had this overhauled, new springs, brushes etc., just yesterday. > > Has anyone seen a failure like this in their experience? Anywhere else I could look? It's really a very simple circuit and it must be drawing several hundred amps somewhere... > > ________________________________ Message 4 _____________________________________ Time: 02:19:22 PM PST US Subject: Re: AeroElectric-List: Problem with starting From: Alec Myers I did do a capacity check with a hand held device (basically it had a big heating element in it) that runs for ten seconds and gives a go/no-go result - it said the battery was "go". The bit that confuses me about a failing battery being responsible is that on one start the battery will produce enough current to pull the bus voltage down to 6 volts and significantly heat the battery grounding strap (but in this scenario not turn the prop), and on the very next try the bus voltage only drops to 10 volts while the prop spins freely. On 17Jun2016, at 4:56 PM, Kelly McMullen wrote: Most likely your battery is on its last legs, or it has not achieved a full charge. After being charged, and sitting overnight, the battery resting voltage should be at least 12.7. If it is closer to 12.5, the battery is either weak or didn't get fully charged. You could do, or have done a capacity check. On 6/17/2016 1:44 PM, Alec Myers wrote: > > Fresh on the heels of asking for help with the low bus voltage with the engine running in my C182, I now have an issue with intermittent cranking on start. > > Symptoms: > > About 5 times out of 10 turning the key switch to start elicits no prop movement. Not even a tiny bit. The other times the cranking is healthy. > > During a no-turn start, I can hear the starter contactor oscillate on/off at about 5Hz, the bus voltage drops to 6 volts or below, and after a few seconds the earth braid from the battery to the fuselage gets warm/hot to touch. > > Yesterday I had the alternator overhauled, and replaced: no change in behaviour. Sometimes it cranks well 10 times in a row, sometimes it fails to turn, 10 times in a row. > > After a few trial starts today the battery was dead. So I gave it an external charge 20A for an hour. The next start failed. The one after that was fine, then it went sulky and failed a few times. > > Twice in maybe 40 trial starts (been working on this at various times over two days now) the main (battery) contactor has remained shut and I have been unable to shut off the power by turning off the master switch. The second time this happened I gently tapped the battery contactor with a rubber tool and the contact was successfully broken. I have now replaced this contactor. I imagine this stuck-on behaviour is because the contact has tried to open due to low coil voltage and welded itself shut because of an overcurrent condition. > > Twice overall I have seen it enter this failure mode during cranking and while the prop is turning: the prop stops and bounces back against the cylinder compression, the bus voltage drops out and the contactor starts to buzz. > > This is all consistent with a dead short either in, or downstream of the starter contactor. I would be looking very hard at the starter motor, but I've already had this overhauled, new springs, brushes etc., just yesterday. > > Has anyone seen a failure like this in their experience? Anywhere else I could look? It's really a very simple circuit and it must be drawing several hundred amps somewhere... > > > > > > > ________________________________ Message 5 _____________________________________ Time: 02:33:50 PM PST US From: Justin Jones Subject: Re: AeroElectric-List: Problem with starting This sounds like an internal problem inside the starter or possibly a chaffing wire (insulation rubbing thin or thru and grounding out) on the starter side on the main contactor. The problem with high current draws is that it can harm the components in the system. The battery, wires, and both contactors can be destroyed. Begin at the starter and trace the big wire all the way back to the battery looking for any signs of chaffing or shorts. Do a continuity check between ground and the main wire on the starter side of the contactors with the battery switch off and battery disconnected from the airframe. If you can't find an issue with the wire, try trying to disconnect the main wire from the starter, insulate it (electricity isolating it) and attempt to crank the starter as you would on a normal start (battery connected). If the battery grounding braid gets hot, the starter isn't the issue and you have a short to ground. If nothing happens, try a different starter. Let us know. Justin > On Jun 17, 2016, at 16:56, Kelly McMullen wrote: > > > Most likely your battery is on its last legs, or it has not achieved a full charge. After being charged, and sitting overnight, the battery resting voltage should be at least 12.7. If it is closer to 12.5, the battery is either weak or didn't get fully charged. You could do, or have done a capacity check. > >> On 6/17/2016 1:44 PM, Alec Myers wrote: >> >> Fresh on the heels of asking for help with the low bus voltage with the engine running in my C182, I now have an issue with intermittent cranking on start. >> >> Symptoms: >> >> About 5 times out of 10 turning the key switch to start elicits no prop movement. Not even a tiny bit. The other times the cranking is healthy. >> >> During a no-turn start, I can hear the starter contactor oscillate on/off at about 5Hz, the bus voltage drops to 6 volts or below, and after a few seconds the earth braid from the battery to the fuselage gets warm/hot to touch. >> >> Yesterday I had the alternator overhauled, and replaced: no change in behaviour. Sometimes it cranks well 10 times in a row, sometimes it fails to turn, 10 times in a row. >> >> After a few trial starts today the battery was dead. So I gave it an external charge 20A for an hour. The next start failed. The one after that was fine, then it went sulky and failed a few times. >> >> Twice in maybe 40 trial starts (been working on this at various times over two days now) the main (battery) contactor has remained shut and I have been unable to shut off the power by turning off the master switch. The second time this happened I gently tapped the battery contactor with a rubber tool and the contact was successfully broken. I have now replaced this contactor. I imagine this stuck-on behaviour is because the contact has tried to open due to low coil voltage and welded itself shut because of an overcurrent condition. >> >> Twice overall I have seen it enter this failure mode during cranking and while the prop is turning: the prop stops and bounces back against the cylinder compression, the bus voltage drops out and the contactor starts to buzz. >> >> This is all consistent with a dead short either in, or downstream of the starter contactor. I would be looking very hard at the starter motor, but I've already had this overhauled, new springs, brushes etc., just yesterday. >> >> Has anyone seen a failure like this in their experience? Anywhere else I could look? It's really a very simple circuit and it must be drawing several hundred amps somewhere... > > > > ________________________________ Message 6 _____________________________________ Time: 02:36:55 PM PST US From: Justin Jones Subject: Re: AeroElectric-List: Problem with starting Alec, this is typical behavior of a short. See my last post to trouble shoot and find the issue. > On Jun 17, 2016, at 17:18, Alec Myers wrote: > > > I did do a capacity check with a hand held device (basically it had a big heating element in it) that runs for ten seconds and gives a go/no-go result - it said the battery was "go". > > The bit that confuses me about a failing battery being responsible is that on one start the battery will produce enough current to pull the bus voltage down to 6 volts and significantly heat the battery grounding strap (but in this scenario not turn the prop), and on the very next try the bus voltage only drops to 10 volts while the prop spins freely. > > > > > On 17Jun2016, at 4:56 PM, Kelly McMullen wrote: > > > Most likely your battery is on its last legs, or it has not achieved a full charge. After being charged, and sitting overnight, the battery resting voltage should be at least 12.7. If it is closer to 12.5, the battery is either weak or didn't get fully charged. You could do, or have done a capacity check. > >> On 6/17/2016 1:44 PM, Alec Myers wrote: >> >> Fresh on the heels of asking for help with the low bus voltage with the engine running in my C182, I now have an issue with intermittent cranking on start. >> >> Symptoms: >> >> About 5 times out of 10 turning the key switch to start elicits no prop movement. Not even a tiny bit. The other times the cranking is healthy. >> >> During a no-turn start, I can hear the starter contactor oscillate on/off at about 5Hz, the bus voltage drops to 6 volts or below, and after a few seconds the earth braid from the battery to the fuselage gets warm/hot to touch. >> >> Yesterday I had the alternator overhauled, and replaced: no change in behaviour. Sometimes it cranks well 10 times in a row, sometimes it fails to turn, 10 times in a row. >> >> After a few trial starts today the battery was dead. So I gave it an external charge 20A for an hour. The next start failed. The one after that was fine, then it went sulky and failed a few times. >> >> Twice in maybe 40 trial starts (been working on this at various times over two days now) the main (battery) contactor has remained shut and I have been unable to shut off the power by turning off the master switch. The second time this happened I gently tapped the battery contactor with a rubber tool and the contact was successfully broken. I have now replaced this contactor. I imagine this stuck-on behaviour is because the contact has tried to open due to low coil voltage and welded itself shut because of an overcurrent condition. >> >> Twice overall I have seen it enter this failure mode during cranking and while the prop is turning: the prop stops and bounces back against the cylinder compression, the bus voltage drops out and the contactor starts to buzz. >> >> This is all consistent with a dead short either in, or downstream of the starter contactor. I would be looking very hard at the starter motor, but I've already had this overhauled, new springs, brushes etc., just yesterday. >> >> Has anyone seen a failure like this in their experience? Anywhere else I could look? It's really a very simple circuit and it must be drawing several hundred amps somewhere... > > > > > > > > > > ________________________________ Message 7 _____________________________________ Time: 02:53:26 PM PST US From: Subject: Re: AeroElectric-List: Problem with starting ---- Alec Myers wrote: > > I did do a capacity check with a hand held device (basically it had a big heating element in it) that runs for ten seconds and gives a go/no-go result - it said the battery was "go". > > The bit that confuses me about a failing battery being responsible is that on one start the battery will produce enough current to pull the bus voltage down to 6 volts and significantly heat the battery grounding strap (but in this scenario not turn the prop), and on the very next try the bus voltage only drops to 10 volts while the prop spins freely. That the ground braid gets hot suggests a poor connection. I would disconnect the braid and clean or replace and try again. jrh ________________________________ Message 8 _____________________________________ Time: 03:07:05 PM PST US From: Alec Myers Subject: Re: AeroElectric-List: Problem with starting The wire between the contactor and the starter is only six inches long no chafing anywhere or even contact with anything else. I can be confident there's no short upstream of the starter contactor because the bus voltage dips out only when the starter contactor is energized. I have disconnected the starter from its contactor and hit the start switch. The contactor closes but there is no drop in bus voltage. As you would expect. The only thing that makes me hesitate from blaming the starter motor 100% is that the fault is intermittent so not seeing it on a few tests without the starter in the circuit isn't entirely dispositive that the starter is the problem. I could have just got lucky, and without the starter and engine turning there's no vibration to shake things up. Is it at all possible the contactor is intermittently shorting to the can? I am going to try to find a DC clamp-on current meter. If while stalled there's about 200+ amps in the contactor-starter wire then the motor has to be the issue. Unfortunately sourcing another starter just to try is infeasible. On Jun 17, 2016, at 17:32, Justin Jones wrote: This sounds like an internal problem inside the starter or possibly a chaffing wire (insulation rubbing thin or thru and grounding out) on the starter side on the main contactor. The problem with high current draws is that it can harm the components in the system. The battery, wires, and both contactors can be destroyed. Begin at the starter and trace the big wire all the way back to the battery looking for any signs of chaffing or shorts. Do a continuity check between ground and the main wire on the starter side of the contactors with the battery switch off and battery disconnected from the airframe. If you can't find an issue with the wire, try trying to disconnect the main wire from the starter, insulate it (electricity isolating it) and attempt to crank the starter as you would on a normal start (battery connected). If the battery grounding braid gets hot, the starter isn't the issue and you have a short to ground. If nothing happens, try a different starter. Let us know. Justin > On Jun 17, 2016, at 16:56, Kelly McMullen wrote: > > > Most likely your battery is on its last legs, or it has not achieved a full charge. After being charged, and sitting overnight, the battery resting voltage should be at least 12.7. If it is closer to 12.5, the battery is either weak or didn't get fully charged. You could do, or have done a capacity check. > >> On 6/17/2016 1:44 PM, Alec Myers wrote: >> >> Fresh on the heels of asking for help with the low bus voltage with the engine running in my C182, I now have an issue with intermittent cranking on start. >> >> Symptoms: >> >> About 5 times out of 10 turning the key switch to start elicits no prop movement. Not even a tiny bit. The other times the cranking is healthy. >> >> During a no-turn start, I can hear the starter contactor oscillate on/off at about 5Hz, the bus voltage drops to 6 volts or below, and after a few seconds the earth braid from the battery to the fuselage gets warm/hot to touch. >> >> Yesterday I had the alternator overhauled, and replaced: no change in behaviour. Sometimes it cranks well 10 times in a row, sometimes it fails to turn, 10 times in a row. >> >> After a few trial starts today the battery was dead. So I gave it an external charge 20A for an hour. The next start failed. The one after that was fine, then it went sulky and failed a few times. >> >> Twice in maybe 40 trial starts (been working on this at various times over two days now) the main (battery) contactor has remained shut and I have been unable to shut off the power by turning off the master switch. The second time this happened I gently tapped the battery contactor with a rubber tool and the contact was successfully broken. I have now replaced this contactor. I imagine this stuck-on behaviour is because the contact has tried to open due to low coil voltage and welded itself shut because of an overcurrent condition. >> >> Twice overall I have seen it enter this failure mode during cranking and while the prop is turning: the prop stops and bounces back against the cylinder compression, the bus voltage drops out and the contactor starts to buzz. >> >> This is all consistent with a dead short either in, or downstream of the starter contactor. I would be looking very hard at the starter motor, but I've already had this overhauled, new springs, brushes etc., just yesterday. >> >> Has anyone seen a failure like this in their experience? Anywhere else I could look? It's really a very simple circuit and it must be drawing several hundred amps somewhere... ________________________________ Message 9 _____________________________________ Time: 03:53:51 PM PST US From: "David Lloyd" Subject: Re: AeroElectric-List: Problem with starting It is unusual but, a contactor can go bad. Usually if it is mounted the wrong orientation and gets moisture inside causing fungus or electrolysis corrosion on the contact surfaces that carry the heavy current. Since you state that the contactor and lead cable get warm/hot then, this does not point to a failing ignition start switch usually. The starting circuit to activate the contactor is fairly low current; about 5 amps or less. Another unusual failure is in the starter motor windings. The winding could have a cracked armature heavy wire that makes or un-makes at random times. Usually when heat is involved. I have seen this failure in alternators also. Very difficult to chase down.. . . ------------------------------------------------------------------------------------ ----- Original Message ----- From: "Alec Myers" Sent: Friday, June 17, 2016 1:44 PM Subject: AeroElectric-List: Problem with starting > > Fresh on the heels of asking for help with the low bus voltage with the > engine running in my C182, I now have an issue with intermittent cranking > on start. > > Symptoms: > > About 5 times out of 10 turning the key switch to start elicits no prop > movement. Not even a tiny bit. The other times the cranking is healthy. > > During a no-turn start, I can hear the starter contactor oscillate on/off > at about 5Hz, the bus voltage drops to 6 volts or below, and after a few > seconds the earth braid from the battery to the fuselage gets warm/hot to > touch. > > Yesterday I had the alternator overhauled, and replaced: no change in > behaviour. Sometimes it cranks well 10 times in a row, sometimes it fails > to turn, 10 times in a row. > > After a few trial starts today the battery was dead. So I gave it an > external charge 20A for an hour. The next start failed. The one after that > was fine, then it went sulky and failed a few times. > > Twice in maybe 40 trial starts (been working on this at various times over > two days now) the main (battery) contactor has remained shut and I have > been unable to shut off the power by turning off the master switch. The > second time this happened I gently tapped the battery contactor with a > rubber tool and the contact was successfully broken. I have now replaced > this contactor. I imagine this stuck-on behaviour is because the contact > has tried to open due to low coil voltage and welded itself shut because > of an overcurrent condition. > > Twice overall I have seen it enter this failure mode during cranking and > while the prop is turning: the prop stops and bounces back against the > cylinder compression, the bus voltage drops out and the contactor starts > to buzz. > > This is all consistent with a dead short either in, or downstream of the > starter contactor. I would be looking very hard at the starter motor, but > I've already had this overhauled, new springs, brushes etc., just > yesterday. > > Has anyone seen a failure like this in their experience? Anywhere else I > could look? It's really a very simple circuit and it must be drawing > several hundred amps somewhere... > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.