AC Voltage Output Testing

[gs11ezrydr]

I need a little assistance in getting my head around testing AC voltage from a stator properly.I have the same resistance between all 3 of my stator output wires, (.4) And none of them are shorted to ground,My AC voltage output testing between each lead is about 30 VAC at idle and goes up to about 65 VAC or so when revved up (approx 4-5k).Should I get any AC voltage testing each lead to ground? I placed the +positive tester lead to each of the stator output wires and the -negative tester lead to the engine ground and I get about 13 VAC at idle and it goes up to about 28 VAC revved up. From what I understand I should get no AC voltage testing to ground as I did.I have read the stator papers etc. and every thing else I could find and I don't see this test mentioned any where.From what I understand or possibly confirm is that the insulation has broken down in my stator windings but not shorted to ground yet therefore bleeding some of the AC voltage to the ground and that is why I get this reading and it is also why my AC voltage is low 65 instead of 80 plus. Can any one confirm this test? I would greatly appreciate any and all input.

 

[posplayr]

That is a fail; consider yourself lucky you caught it now rather than going through repeated teardowns with a temperature dependent insulation break down.


You should read the GS Charging Health more closely especially the revised versions of the stator pages (Phase A and Phase B). See Phase B tests below that mention this test you stumbled into.

And here are some updates with background to the Phase B tests that focus on the stator alone.

A revised test is at this link; The actual test is on Page 6 of 9. We added the leg to ground AC voltage test as this helps isolate insulation breakdowns to ground using the relatively high 60-80 VAC stator voltage when it is open loop.

Link to Revised PHASE B of Stator Pages with discussion of testing methods:
http://www.keepandshare.com/doc/3977567/dummy-load-scanned-pdf-may-14-2012-8-24-pm-649k?da=y

original link with a lot of discussion

http://www.thegsresources.com/_forum/showthread.php?t=174130&highlight=revised+phase

 

[gs11ezrydr]

Thank You big time :dancing: I have read this before some where on here a while back but wasn't really sure and I could not find it to save my life. I got a unit in today with this charging problem and probally spent and hour or so testing and retesting and finally decieded to ask the masters at GSresources and wala you saved my A**.So now I have book marked and downloaded this info for future use. Thanks again

 

[posplayr]

Thank You big time :dancing: I have read this before some where on here a while back but wasn't really sure and I could not find it to save my life. I got a unit in today with this charging problem and probally spent and hour or so testing and retesting and finally decieded to ask the masters at GSresources and wala you saved my A**.So now I have book marked and downloaded this info for future use. Thanks again

If this is for someone else (paying customer) either get a SH-775 or pop for the Compufire to avoid any further issues. Both are SERIES R/R's

 

[gs11ezrydr]

Thanks again and yes I have reccommended that to the customer but they have already replaced the R/R before bringing it in to me today. But it was getting really hot to the touch within 10 -20 seconds or so when testing. So I unhooked it and proceded to check the stator.With any luck it may be ok. But if not and its fried again and we will go back with one of the R/R units you have described.I still need to go through the wiring harness,positive lead,grounds,etc. before I call this one fixed and burn up any of the new parts being installed since the R/R was getting so hot so fast.Or maybe the stator being partially shorted could have caused the overheating issue. ????

 

[posplayr]

Thanks again and yes I have reccommended that to the customer but they have already replaced the R/R before bringing it in to me today. But it was getting really hot to the touch within 10 -20 seconds or so when testing. So I unhooked it and proceded to check the stator.With any luck it may be ok. But if not and its fried again and we will go back with one of the R/R units you have described.I still need to go through the wiring harness,positive lead,grounds,etc. before I call this one fixed and burn up any of the new parts being installed since the R/R was getting so hot so fast.Or maybe the stator being partially shorted could have caused the overheating issue. ????

If it is getting hot it is probably still OK.

I bought a brand new Electrosport R/R once and had plugged it into my harness. I was happy as it used the OEM plug in my brand new harness. After running the engine about 1 minute the R/R was very hot to the touch. It turned out there were some crappy crimps on the positive lead which allowed the wires to virtually just slide out. So even though it was bright and shiny copper, it was a lousy connection.

The lousy connection looks like high resistance and as soon as the R/R pushes current there is a big voltage drop between R/R and battery making the battery voltage look much higher than it is. The SHUNT R/R immediately shorts the stator and it just stays that way giving the stator and the R/R a stress test. The stator is shorted getting hot and the R/R is holding the short on making it hot

So when people post about disconnect their R/R from the battery and running the engine I shake my head.

I pulled the unit and cut the connector off of it.