---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 02/10/09: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:35 AM - Re: Measuring actual system current (Jim McBurney) 2. 09:40 AM - Re: Measuring actual system current (The Kuffels) 3. 01:23 PM - Re: Measuring actual system current (Dale Rogers) 4. 02:03 PM - Re: Measuring actual system current (Allen Fulmer) 5. 03:51 PM - Engine ground on RV 10 (Vernon Smith) 6. 05:49 PM - Comic Book for Crimping TNC Connectors (Bret Smith) 7. 07:37 PM - Re: Measuring actual system current (Robert L. Nuckolls, III) 8. 07:38 PM - Re: Engine ground on RV 10 (Robert L. Nuckolls, III) 9. 07:47 PM - Re: Comic Book for Crimping TNC Connectors (Robert L. Nuckolls, III) 10. 08:30 PM - z-14 ? (TimRhod@aol.com) 11. 09:05 PM - Re: Engine ground on RV 10 (Vernon Smith) ________________________________ Message 1 _____________________________________ Time: 08:35:13 AM PST US From: "Jim McBurney" Subject: Re: AeroElectric-List: Measuring actual system current Sam (and List), Frank is right -- the Fluke meters Jon referenced won't work on DC. Fluke (Cadillac of meters) does sell DC clamp meters, for MANY hundreds of dollars! However, here's a reference to a Craftsman AC/DC clamp meter that works well, for about 60 bucks: http://www.sears.com/shc/s/p_10153_12605_03482369000P?mv=rr Blue skies and tailwinds Jim CH-801 DeltaHawk diesel Augusta GA 90% done, 90% left ________________________________ Message 2 _____________________________________ Time: 09:40:46 AM PST US From: "The Kuffels" Subject: Re: AeroElectric-List: Measuring actual system current Sam, << Is there a way to measure the actual current draw of a system? .. Dynon D180 EFIS/EMS. >> The D180 comes with an accurate current shunt. If you installed your shunt as an alternator load meter (Position B of page 3-12 of the current [Rev E] D180 Installation Manual, between the alternator output and everything else) then temporarily install it in Position A (between the output of the Master Relay and everything else but the Starter Relay) or Position C (between the junction of the Master Relay - Alternator Output and the aircraft buss) whichever is mechanically easier. Start your engine, charge up the battery and then turn off the alternator if your shunt is in Position A. The Dynon will now give you detailed readout of current draw (and difference in draw) with various pieces turned on or off. The one item missing is the current draw for the Master Relay. My B&C 4-terminal style Master Relay uses 0.70 amps. Tom Kuffel ________________________________ Message 3 _____________________________________ Time: 01:23:12 PM PST US From: Dale Rogers Subject: Re: AeroElectric-List: Measuring actual system current Sam Hoskins wrote: > The reason I can't use the ammeter, I think, is that the readings > would be clouded by charging/discharging of the battery. Nope. An ammeter measures current passing through it - period. ~The~ airplane ammeter is just placed between the battery and ~everything else~. To measure current in a branch circuit, you need another ammeter. Open the circuit you want to check and insert the ammeter (or ammeter/shunt combo). Run the device(s) you want verified; measure the current draw. When testing is complete remove ammeter and restore original circuit configuration. Dale R. ________________________________ Message 4 _____________________________________ Time: 02:03:24 PM PST US From: "Allen Fulmer" Subject: RE: AeroElectric-List: Measuring actual system current I bought one of these recommended by someone else. Seems to work fine and nice addition to toolbox. http://www.extech.com/instrument/products/alpha/MA220.html Allen Fulmer ________________________________ Message 5 _____________________________________ Time: 03:51:21 PM PST US From: Vernon Smith Subject: AeroElectric-List: Engine ground on RV 10 Hi All=2C I'm building an RV 10 with the 12v battery locally grounded and mounted in the tail. Where is a good place to locally ground the engine on the airfram e? Possible engine grounding options are: 1. To a ground forest mounted on the stainless firewall. Q: Will the thin s tainless handle the current during the starting of an IO 540? 2. To one of the engine mount/airframe bolts. 3. To the engine mount (Yes=2C I've read Bob's article against using this b ut through it in anyway.) 3. Other options? I really don't want to run a negative cable back to the battery (~12 foot o f #2 cable.) I have looked through the archives and this subject has been n ibbled around both here and on the RV 10 list=2C but not hit square on the head. I look forward to you comments. Thanks=2C Vernon Smith (#324 RV 10 finishing) _________________________________________________________________ Windows Live=99: Keep your life in sync. http://windowslive.com/howitworks?ocid=TXT_TAGLM_WL_t1_allup_howitworks_0 22009 ________________________________ Message 6 _____________________________________ Time: 05:49:02 PM PST US From: "Bret Smith" Subject: AeroElectric-List: Comic Book for Crimping TNC Connectors Bob, anyone, does anyone have any idea of the lengths to trim the RG-400 coax for an AMP TNC connector? This connector is required to install the GPS antenna for the Garmin 430W. Bret Smith RV-9A N16BL Blue Ridge, Ga www.FlightInnovations.com ________________________________ Message 7 _____________________________________ Time: 07:37:26 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Measuring actual system current At 08:31 AM 2/9/2009, you wrote: >Is there a way to measure the actual current draw of a system? I >finally got my electrically dependent engine started >(www.samhoskins.blogspot.com) >yesterday and I am using a version of Z-19/RB with a B&C 30A >permemant magnet alternator. I have the primary battery installed >and a Dynon D180 EFIS/EMS. > >I would like to be able to determine the real (not estimated) >current draw of the system. Once I know that, I will select the >appropriate back-up battery, trying to keep it as light as possible. > >There is an ammeter installed, but I don't think that would help for >this data collection. Does anyone have any suggestions how I might >go about this? If you have breakers, then open the breaker that supplies the load of interest and clip an ammeter across the open breaker. If you have fuses, pull the fuse and clip the meter between the fat power stud at the end of the fuseholder and the other end to the output tab for that fuse. Even the cheapest multimeter you can find will do for this task. http://aeroelectric.com/Pictures/Tools/Test_Equipment/tenma1.jpg Harbor Freight sells something like this for about $3 on sale . . . regularly $9 I think. For your task, I recommend you cut the probes off of the test leads and install alligator clips with rubber booties over them so that you can do "clip on" connections that will stay in place while you manipulate ship's accessories taking measurements. If you're interested in e-bus loads, clip the mulitmeter across an open e-bus alternate feed switch with the battery master OFF. This will get you the total e-bus load which is quite useful for adjusting battery size. Remember that a battery's useful capacity goes DOWN as load increases. A 17 a.h. battery is good for that amount with a 20 hour discharge rate. When you hang say a 4A e-bus load on it, you won't get the full 17 a.h. . . . it will be more like 13-14 a.h. Bob . . . ________________________________ Message 8 _____________________________________ Time: 07:38:25 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Engine ground on RV 10 At 05:49 PM 2/10/2009, you wrote: >Hi All, > >I'm building an RV 10 with the 12v battery locally grounded and >mounted in the tail. Where is a good place to locally ground the >engine on the airframe? > >Possible engine grounding options are: > >1. To a ground forest mounted on the stainless firewall. Q: Will the >thin stainless handle the current during the starting of an IO 540? > >2. To one of the engine mount/airframe bolts. > >3. To the engine mount (Yes, I've read Bob's article against using >this but through it in anyway.) > >3. Other options? > >I really don't want to run a negative cable back to the battery (~12 >foot of #2 cable.) I have looked through the archives and this >subject has been nibbled around both here and on the RV 10 list, but >not hit square on the head. I look forward to you comments. The big guys have been using airframes for cranking current grounds for many, many moons. In this case, ground crankcase to forest-of-tabs bolt with a braid strap -AND- it wouldn't hurt to add the jumper straps around the shock mounts like the big guys too . . . Bob . . . ________________________________ Message 9 _____________________________________ Time: 07:47:21 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Comic Book for Crimping TNC Connectors At 07:47 PM 2/10/2009, you wrote: >Bob, anyone, does anyone have any idea of the lengths to trim the >RG-400 coax for an AMP TNC connector? This connector is required to >install the GPS antenna for the Garmin 430W. > It's the same as the BNC. See: http://aeroelectric.com/Mfgr_Data/Connectors/AMP_Tyco/TNC_Installation.pdf Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 10 ____________________________________ Time: 08:30:40 PM PST US From: TimRhod@aol.com Subject: AeroElectric-List: z-14 ? To Bob Nuckols I have a Velocity with a Z-14 wire configuration. I have duel light speed electronic ignitions wired directly to the two respective batteries . In the event of a dead battery how do you get the dead battery contactor closed with the other system so you can charge the dead battery which keeps its respective electric ignition going. I know there is a solution because you gave it to me a few years ago and I was able to do the following . Recently I had a dead auxillary battery due to leaving on the pitot heat. I started the engine with main battery and was able to close the auxillary contactor with power from the main system. I believe this was from a modification you had suggested to me when I wired the system. I can't remember what the modification was. Could you repeat it for me? I love this system because I was facing a long X-country flight and I was able to still go due to still having one good battery and two alternators. Love the redundancy!!! Fantastic!!! Thanks Tim **************A Good Credit Score is 700 or Above. See yours in just 2 easy steps! bemailfooterNO62) ________________________________ Message 11 ____________________________________ Time: 09:05:56 PM PST US From: Vernon Smith Subject: RE: AeroElectric-List: Engine ground on RV 10 Bob=2C Thanks for the response. Got it=2C two braided jumper straps. That's one le ss thing to obsess over! Vern do not archive > Date: Tue=2C 10 Feb 2009 21:37:44 -0600 > To: aeroelectric-list@matronics.com > From: nuckolls.bob@aeroelectric.com > Subject: Re: AeroElectric-List: Engine ground on RV 10 > kolls.bob@aeroelectric.com> > > At 05:49 PM 2/10/2009=2C you wrote: > >Hi All=2C > > > >I'm building an RV 10 with the 12v battery locally grounded and > >mounted in the tail. Where is a good place to locally ground the > >engine on the airframe? > > > >Possible engine grounding options are: > > > >1. To a ground forest mounted on the stainless firewall. Q: Will the > >thin stainless handle the current during the starting of an IO 540? > > > >2. To one of the engine mount/airframe bolts. > > > >3. To the engine mount (Yes=2C I've read Bob's article against using > >this but through it in anyway.) > > > >3. Other options? > > > >I really don't want to run a negative cable back to the battery (~12 > >foot of #2 cable.) I have looked through the archives and this > >subject has been nibbled around both here and on the RV 10 list=2C but > >not hit square on the head. I look forward to you comments. > > The big guys have been using airframes for cranking > current grounds for many=2C many moons. In this case=2C > ground crankcase to forest-of-tabs bolt with a braid > strap -AND- it wouldn't hurt to add the jumper straps > around the shock mounts like the big guys too . . . > > Bob . . . > > =========== =========== =========== =========== > > > _________________________________________________________________ Windows Live=99: E-mail. Chat. Share. 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