---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 10/08/10: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:33 AM - Re: Z8 Ground Power test switch (user9253) 2. 12:49 PM - 3300 alternator fuse (bob noffs) 3. 01:41 PM - Re: Z8 Ground Power test switch (jonlaury) 4. 01:48 PM - Re: Z8 Ground Power test switch (jonlaury) 5. 04:28 PM - Re: Re: Z8 Ground Power test switch (Bob McCallum) 6. 04:44 PM - Re: Re: Z8 Ground Power test switch (Bob McCallum) 7. 10:22 PM - Re: Z8 Ground Power test switch (jonlaury) ________________________________ Message 1 _____________________________________ Time: 07:33:07 AM PST US Subject: AeroElectric-List: Re: Z8 Ground Power test switch From: "user9253" John, How about this circuit? http://lh4.ggpht.com/_9Rmupq9lpCs/TK8pD8j5DCI/AAAAAAAAAFA/CwjWt8-Vr8o/s640/Gnd%20Pwr001.jpg Move the switch up between the diode and the contactor coil. The OV protection will always pop the breaker regardless of switch position. The switch will enable the contactor coil or the lamp. The other half of the switch can control the aux alternator as in your original circuit. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=315100#315100 ________________________________ Message 2 _____________________________________ Time: 12:49:38 PM PST US Subject: AeroElectric-List: 3300 alternator fuse From: bob noffs thank you bob for the reply to my question. bob noffs ________________________________ Message 3 _____________________________________ Time: 01:41:50 PM PST US Subject: AeroElectric-List: Re: Z8 Ground Power test switch From: "jonlaury" Joe, That's great! I incorporated it in the attached. I'm still a bit unclear about why the diode is located where it is, but as long as it's correct, I'll read up on that later. Thanks a bunch, John Read this topic online here: http://forums.matronics.com/viewtopic.php?p=315140#315140 Attachments: http://forums.matronics.com//files/z8_w_sb_alt_gpj_conceptual_rev_a__114.pdf ________________________________ Message 4 _____________________________________ Time: 01:48:49 PM PST US Subject: AeroElectric-List: Re: Z8 Ground Power test switch From: "jonlaury" Positive Ground Power correction and drawing cleanup Read this topic online here: http://forums.matronics.com/viewtopic.php?p=315145#315145 Attachments: http://forums.matronics.com//files/z8_w_sb_alt_gpj_conceptual_rev_a__188.pdf ________________________________ Message 5 _____________________________________ Time: 04:28:23 PM PST US From: Bob McCallum Subject: RE: AeroElectric-List: Re: Z8 Ground Power test switch Jon; You're showing a jumper between the starter push button and the starter warning light. This means that as soon as you engage the starter with the push button it will latch itself on via this jumper. Probably not a good idea. Bob McC > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list- > server@matronics.com] On Behalf Of jonlaury > Sent: Friday, October 08, 2010 4:46 PM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Re: Z8 Ground Power test switch > > > Positive Ground Power correction and drawing cleanup > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=315145#315145 > > > > > Attachments: > > http://forums.matronics.com//files/z8_w_sb_alt_gpj_conceptual_rev_a__188.pdf > > > > > _- > ==================================================== > ====== > _- > ==================================================== > ====== > _- > ==================================================== > ====== > _- > ==================================================== > ====== > > ________________________________ Message 6 _____________________________________ Time: 04:44:31 PM PST US From: Bob McCallum Subject: RE: AeroElectric-List: Re: Z8 Ground Power test switch Jon; I thought I remembered earlier in this thread that the lamp and diode in your ground power connector wiring was to warn of reverse polarity?? You have in the drawings just submitted, however, connected the external power supply (battery) directly across your auxiliary alternator. Should this be reversed polarity the alternator will be seen as a direct short and most probably its internal rectifiers will instantly fry long before the 40 amp ANL can protect it. To provide reverse polarity protection the external battery should not be connected to anything aboard the aircraft unless the polarity is proven to be correct first. The diode location you're querying causes the lamp to light only if the ground power is correct polarity and only allows you to close the contactor if the polarity is correct, but please note the issue above. Bob McC > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list- > server@matronics.com] On Behalf Of jonlaury > Sent: Friday, October 08, 2010 4:46 PM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Re: Z8 Ground Power test switch > > > Positive Ground Power correction and drawing cleanup > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=315145#315145 > > > > > Attachments: > > http://forums.matronics.com//files/z8_w_sb_alt_gpj_conceptual_rev_a__188.pdf > > > > > _- > ==================================================== > ====== > _- > ==================================================== > ====== > _- > ==================================================== > ====== > _- > ==================================================== > ====== > > ________________________________ Message 7 _____________________________________ Time: 10:22:08 PM PST US Subject: AeroElectric-List: Re: Z8 Ground Power test switch From: "jonlaury" Bob, Thanks for looking this over. The starter jumper was an errant line that was left over after moving some things around. I removed it and connected the warning lamp circuit to the 'I' terminal of the contactor that receives bus voltage when the contactor is closed. > The diode location you're querying causes the lamp to light only if the > ground power is correct polarity and only allows you to close the contactor > if the polarity is correct, but please note the issue above. So wouldn't that provide the needed protection for the alternator? The way I see it is that, if GP polarity is reversed, it only becomes a problem if the Stby Alt switch is closed. I confess that I'm at the ragged end of understanding the circuit and the problems that you foresee. Do you see a solution? John Read this topic online here: http://forums.matronics.com/viewtopic.php?p=315186#315186 ------------------------------------------------------------------------------------- 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.