Today's Message Index:
----------------------
1. 04:14 AM - Re: electric gyros (Richard V. Reynolds)
2. 05:58 AM - Re: Re: Mixing Z13 and Z14 (John Schroeder)
3. 07:03 AM - Re: Re: Mixing Z13 and Z14 (Vern W.)
4. 09:37 AM - Re: Re: Mixing Z13 and Z14 (John Schroeder)
5. 09:58 AM - Intercom Problems in my RV-4 (Dean Pichon)
6. 10:26 AM - Re: Intercom Problems in my RV-4 (Scott Bilinski)
7. 11:26 AM - What is this device? (Hal Kempthorne)
8. 11:28 AM - Re: electric gyros (John Swartout)
9. 11:36 AM - Re: What is this device? (Michael D Crowe)
10. 11:46 AM - Re: electric gyros (Matt Prather)
11. 12:25 PM - Voice annunciation (Glen Matejcek)
12. 01:08 PM - Re: What is this device? (rv-9a-online)
13. 01:11 PM - Re: Intercom Problems in my RV-4 (Earl_Schroeder)
14. 03:27 PM - Re: electric gyros (Robert McCallum)
15. 06:44 PM - Re: electric gyros (Jeff Dowling)
16. 08:20 PM - Re: electric gyros (Jim Stone)
17. 08:30 PM - Re: electric gyros (Matt Prather)
18. 09:38 PM - Re: electric gyros (Robert McCallum)
Message 1
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| Subject: | Re: electric gyros |
--> AeroElectric-List message posted by: "Richard V. Reynolds" <rvreynolds@macs.net>
My RCA-26 draws .76 A at 14 V.
The fuse protects the wire. Fuses do not protect the equipment. If you decide
to use 10 AWG, then use a 30A fuse.
22 AWG typically calls for a 5 A fuse/CB. If you use a smaller fuse, the fuse
will blow before the wire burns, That's GOOD.
Richard Reynolds
RV-6A
"Jones, Michael" wrote:
> --> AeroElectric-List message posted by: "Jones, Michael" <MJones@hatch.ca>
>
> hi all
>
> i have following gyros for my kit plane rc allen dg model rca-15 and horizon
> model rca-26
> i am wondering what the current draw on them is so i dont have to hook up
> and measure
> i seem to have written down that the horizon has written on its case 14 vdc
> and 1.0 amp, if this is true and using say 4ft of wire and figure 11-30 from
> ac 43.13 the wire size is off the chart, so how do you size an item like
> this, perhaps my amps are wrong, if not can someone explain the example i
> see of 22 awg wire and 2 amp cb's
>
> thanx
>
> mike
> murphy rebel#007
>
> NOTICE - This message is the property of HATCH. It may also be
> confidential and/or privileged. If you are not the intended recipient
> of this message you are hereby notified that you must not disseminate,
> copy or take any action with respect to it.
>
> If you have received this message in error please notify
> HATCH immediately via mailto:MailAdmin@hatch.ca.
>
Message 2
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| Subject: | Re: Mixing Z13 and Z14 |
--> AeroElectric-List message posted by: "John Schroeder" <jschroeder@perigee.net>
Vern -
We did a solution similar to Dan's. We are using the basic Z-14 &
installing the SD-20 on an IO-550. We are not crossfeeding for start. So
we are installing 2 20 AH batteries. The #1 battery holder is large enough
to go to a 25AH battery if necessary for cranking. The original design was
to accommodate two items that may have brown-out problems. One was the
aerosance FADEC; which would not function if the busses went below a
certain voltage due to cranking. We also wanted to have a separate buss
arrangement for each of the two fadec channels. The other was because of
Blue Mountain's design of the EFIS ONE. Once the FADEC solution was
decided it made sense to put the EFIS on the # 2 buss and not worry about
cranking effects on the EFIS or fadec. Since then, we canned the fadec,
but are keeping the same architecture. Eventually we will add electronic
ignition and separate channels would work for that.
I have a .pdf of the Z-14 power layout if you would like to look at it.
Cheers,
John
> --> AeroElectric-List message posted by: "Dan O'Brien"
> <danobrien@cox.net>
>
>
> Vern,
>
> I had the same question a couple years ago. The following exchange with
> Bob helped me. I decided to go with Z-14.
>
> >I am planning on using the SD-20 so I can have a little
> >more juice in the event of main alternator
> >failure (to cover pitot heat, for example.)
> >How should Z-13 be modified to wire in the SD-20 instead
> >of the SD-8?
>
> Bob wrote:
> How about a variation on Z-14. Use S704-1 relays for
> a low current (30A) cross-feed, and as the battery
> relay for a small (6 a.h. or so) battery to stabilize
> the SD-20 when the cross-feed is open. Use the Aux
> Bus as you would the E-bus and put all the main-alt-out
> en route loads on the Aux Bus. You wouldn't close the
> cross-feed during cranking in this case so a single
> pole, single throw cross-feed switch would suffice.
Message 3
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| Subject: | Re: Mixing Z13 and Z14 |
--> AeroElectric-List message posted by: "Vern W." <vernw@ev1.net>
Thanks to John and the others who have had some good comments on this
subject, and I'm still listening if others have something to add. I hope
discussing this publicly also helps others in the middle of planning their
electrical systems.
The reason I like the Z13 design so much is that it's really a very
simple system that can overcome either an in-air primary alternator failure
or a battery failure (or both, for that matter).
What I'm building is a "cross country" RV7-A with all electric IFR panel
plus Electronic ignition so I definitely want to make my electrical system
bullet proof. At the same time, being an RV, I'd rather not carry an extra
battery if I don't have to as long as I get the backup power I can count on.
Plus, I would be in a less puckerable situation if the backup alternator was
able to supply 20 amps rather than just 8 amps.
In my mind, and thinking through various failure scenarios, the Z13
design with the SD20 (instead of the SD8) is really as reliable as the Z14
and without the extra weight of an additional battery.
If both alternators AND a single battery (Z13 design) were to fail at
the same moment, then considering the odds against a failure of that nature,
I'm thinking that perhaps that would mean that I just got a direct
invitation to have a personal conversation with God. :-|
So you see my quandry. I'm not considering so much to save money because
either way costs lots of $$. I'm more concerned with not needing to add
another battery on a light aircraft, but still end up with enough dependable
power so that the flight can end uneventfully and with almost all electrics
humming along nicely on just the SD20 if need be.
Even though Bob (hisownself) says that just replacing the SD8 with the
SD20 "wouldn't be (his) choice of architectures", I still want to explore
that possibility. He doesn't argue against it from a dependability
standpoint, he just seems to think that (probably) for the money, you might
as well install a second battery (which I don't want to do).
From what's been said so far, and someone correct me if I'm wrong, it
looks like all I would need to do is to simply use the SD20 in the Z13
schematic instead of the SD8, and still use ALL of the rest of the original
Z13 parts including the regulator shown and the OV Crowbar setup and wire
everything up exactly the same? In other words, just plug in an SD20 instead
of the SD8?
Vern
----- Original Message -----
From: "John Schroeder" <jschroeder@perigee.net>
Subject: Re: AeroElectric-List: Re: Mixing Z13 and Z14
> --> AeroElectric-List message posted by: "John Schroeder"
<jschroeder@perigee.net>
>
> Vern -
>
> We did a solution similar to Dan's. We are using the basic Z-14 &
> installing the SD-20 on an IO-550. We are not crossfeeding for start. So
> we are installing 2 20 AH batteries. The #1 battery holder is large enough
> to go to a 25AH battery if necessary for cranking. The original design was
> to accommodate two items that may have brown-out problems. One was the
> aerosance FADEC; which would not function if the busses went below a
> certain voltage due to cranking. We also wanted to have a separate buss
> arrangement for each of the two fadec channels. The other was because of
> Blue Mountain's design of the EFIS ONE. Once the FADEC solution was
> decided it made sense to put the EFIS on the # 2 buss and not worry about
> cranking effects on the EFIS or fadec. Since then, we canned the fadec,
> but are keeping the same architecture. Eventually we will add electronic
> ignition and separate channels would work for that.
>
> I have a .pdf of the Z-14 power layout if you would like to look at it.
>
> Cheers,
>
> John
>
>
> > --> AeroElectric-List message posted by: "Dan O'Brien"
> > <danobrien@cox.net>
> >
> >
> > Vern,
> >
> > I had the same question a couple years ago. The following exchange with
> > Bob helped me. I decided to go with Z-14.
> >
> > >I am planning on using the SD-20 so I can have a little
> > >more juice in the event of main alternator
> > >failure (to cover pitot heat, for example.)
> > >How should Z-13 be modified to wire in the SD-20 instead
> > >of the SD-8?
> >
> > Bob wrote:
> > How about a variation on Z-14. Use S704-1 relays for
> > a low current (30A) cross-feed, and as the battery
> > relay for a small (6 a.h. or so) battery to stabilize
> > the SD-20 when the cross-feed is open. Use the Aux
> > Bus as you would the E-bus and put all the main-alt-out
> > en route loads on the Aux Bus. You wouldn't close the
> > cross-feed during cranking in this case so a single
> > pole, single throw cross-feed switch would suffice.
>
>
Message 4
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| Subject: | Re: Mixing Z13 and Z14 |
--> AeroElectric-List message posted by: "John Schroeder" <jschroeder@perigee.net>
Vern -
I don't have the Z-13 in front of me , but you will have to have an
external regulator for the SD-20. I would put in the LR3 from B&C. It has
a crobaw overvoltage built in.
John
> From what's been said so far, and someone correct me if I'm wrong, it
> looks like all I would need to do is to simply use the SD20 in the Z13
> schematic instead of the SD8, and still use ALL of the rest of the
> original Z13 parts including the regulator shown and the OV Crowbar
> setup and wire
> everything up exa
--
Message 5
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| Subject: | Intercom Problems in my RV-4 |
--> AeroElectric-List message posted by: "Dean Pichon" <deanpichon@msn.com>
I have found, recently, that on cold days my intercom does not work well.
This problem seems to coincide with a "weakened" battery condition caused by
not flying for a couple of weeks. With this combination of cold weather and
weak battery, my intercom generates a lot of static. My transmissions are
difficult to understand due to the static levels, but reception remains
fine. After 30-40 minutes of flying, performance improves dramatically.
The plane has no heat, so I don't believe it is an ambient temperature issue
as the cockpit remains cold. PS Engineering, the manufacturer of my
intercom, has told me that the intercom performance is sensitive to supply
voltage, but once the engine is running, the alternator supplies an
indicated 14.2 volts to the system.
After the airplane sits for a couple of weeks, the battery voltage is about
12.0-12.1 volts (with the instrument panel powered up) Priming with the
electric fuel pump momentarily drops the voltage to 11 volts. Cranking the
engine momentarily drops the voltage to 9+ volts.
Is it likely or possible that my panel is not receiving sufficient voltage
or current to satisfy the needs of the intercom? All other instruments
appear to work properly.
Dean Pichon
Bolton, MA
RV-4
Message 6
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| Subject: | Re: Intercom Problems in my RV-4 |
--> AeroElectric-List message posted by: Scott Bilinski <bilinski@kyocera-wireless.com>
I am no electrical expert but when ever I have run across strange problems
the first thing I check for is a bad ground. Bad or partial grounding of
equipment creates some of the strangest problems. For example a partial
ground on the fire wall may improve after everything heats up and expands.
At 12:56 PM 2/23/2005 -0500, you wrote:
>--> AeroElectric-List message posted by: "Dean Pichon" <deanpichon@msn.com>
>
>I have found, recently, that on cold days my intercom does not work well.
>This problem seems to coincide with a "weakened" battery condition caused by
>not flying for a couple of weeks. With this combination of cold weather and
>weak battery, my intercom generates a lot of static. My transmissions are
>difficult to understand due to the static levels, but reception remains
>fine. After 30-40 minutes of flying, performance improves dramatically.
>
>The plane has no heat, so I don't believe it is an ambient temperature issue
>as the cockpit remains cold. PS Engineering, the manufacturer of my
>intercom, has told me that the intercom performance is sensitive to supply
>voltage, but once the engine is running, the alternator supplies an
>indicated 14.2 volts to the system.
>
>After the airplane sits for a couple of weeks, the battery voltage is about
>12.0-12.1 volts (with the instrument panel powered up) Priming with the
>electric fuel pump momentarily drops the voltage to 11 volts. Cranking the
>engine momentarily drops the voltage to 9+ volts.
>
>Is it likely or possible that my panel is not receiving sufficient voltage
>or current to satisfy the needs of the intercom? All other instruments
>appear to work properly.
>
>Dean Pichon
>Bolton, MA
>RV-4
>
>
Scott Bilinski
Eng dept 305
Phone (858) 657-2536
Pager (858) 502-5190
Message 7
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| Subject: | What is this device? |
--> AeroElectric-List message posted by: Hal Kempthorne <hal_kempthorne@sbcglobal.net>
What the heck is this part? It is red, about half an inch square and about 1/16th
thick plastic with two leads .
Marked
ERIE
3.3 M
100V
Found connect from power bus to ground.
hal
Message 8
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--> AeroElectric-List message posted by: "John Swartout" <jgswartout@earthlink.net>
So, if you are protecting two circuits with one breaker, for instance,
dome light and intercom, does that mean that both must be wired with the
same size wire? Or at least neither wired with a bigger wire than the
c/b is adequate to protect?
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Richard V. Reynolds
Subject: Re: AeroElectric-List: electric gyros
--> AeroElectric-List message posted by: "Richard V. Reynolds"
<rvreynolds@macs.net>
My RCA-26 draws .76 A at 14 V.
The fuse protects the wire. Fuses do not protect the equipment. If you
decide
to use 10 AWG, then use a 30A fuse.
22 AWG typically calls for a 5 A fuse/CB. If you use a smaller fuse, the
fuse
will blow before the wire burns, That's GOOD.
Richard Reynolds
RV-6A
"Jones, Michael" wrote:
> --> AeroElectric-List message posted by: "Jones, Michael"
<MJones@hatch.ca>
>
> hi all
>
> i have following gyros for my kit plane rc allen dg model rca-15 and
horizon
> model rca-26
> i am wondering what the current draw on them is so i dont have to hook
up
> and measure
> i seem to have written down that the horizon has written on its case
14 vdc
> and 1.0 amp, if this is true and using say 4ft of wire and figure
11-30 from
> ac 43.13 the wire size is off the chart, so how do you size an item
like
> this, perhaps my amps are wrong, if not can someone explain the
example i
> see of 22 awg wire and 2 amp cb's
>
> thanx
>
> mike
> murphy rebel#007
>
> NOTICE - This message is the property of HATCH. It may also be
> confidential and/or privileged. If you are not the intended recipient
> of this message you are hereby notified that you must not disseminate,
> copy or take any action with respect to it.
>
> If you have received this message in error please notify
> HATCH immediately via mailto:MailAdmin@hatch.ca.
>
Message 9
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| Subject: | What is this device? |
--> AeroElectric-List message posted by: "Michael D Crowe" <rv8a@bellsouth.net>
Hal,
It is a capacitor. Used for noise filtering.
Mike Crowe
Subject: AeroElectric-List: What is this device?
--> AeroElectric-List message posted by: Hal Kempthorne
<hal_kempthorne@sbcglobal.net>
What the heck is this part? It is red, about half an inch square and about
1/16th thick plastic with two leads .
Marked
ERIE
3.3 M
100V
Found connect from power bus to ground.
hal
Message 10
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--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Errr.. Almost. Should be 'Or at least neither wired with a smaller
wire that the c/b is adequate to protect' Making wire bigger is always
safe. Making wire smaller needs to be done carefully. If you get
a fault to ground, the c/b needs to be small enough that it blows before
the wire gets hot enough to do anything dangerous.
Regards,
Matt-
VE N34RD
> --> AeroElectric-List message posted by: "John Swartout"
> <jgswartout@earthlink.net>
>
> So, if you are protecting two circuits with one breaker, for instance,
> dome light and intercom, does that mean that both must be wired with the
> same size wire? Or at least neither wired with a bigger wire than the
> c/b is adequate to protect?
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
> Richard V. Reynolds
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: electric gyros
>
> --> AeroElectric-List message posted by: "Richard V. Reynolds"
> <rvreynolds@macs.net>
>
> My RCA-26 draws .76 A at 14 V.
>
> The fuse protects the wire. Fuses do not protect the equipment. If you
> decide
> to use 10 AWG, then use a 30A fuse.
>
> 22 AWG typically calls for a 5 A fuse/CB. If you use a smaller fuse, the
> fuse
> will blow before the wire burns, That's GOOD.
>
> Richard Reynolds
> RV-6A
>
> "Jones, Michael" wrote:
>
>> --> AeroElectric-List message posted by: "Jones, Michael"
> <MJones@hatch.ca>
>>
>> hi all
>>
>> i have following gyros for my kit plane rc allen dg model rca-15 and
> horizon
>> model rca-26
>> i am wondering what the current draw on them is so i dont have to hook
> up
>> and measure
>> i seem to have written down that the horizon has written on its case
> 14 vdc
>> and 1.0 amp, if this is true and using say 4ft of wire and figure
> 11-30 from
>> ac 43.13 the wire size is off the chart, so how do you size an item
> like
>> this, perhaps my amps are wrong, if not can someone explain the
> example i
>> see of 22 awg wire and 2 amp cb's
>>
>> thanx
>>
>> mike
>> murphy rebel#007
>>
>> NOTICE - This message is the property of HATCH. It may also be
>> confidential and/or privileged. If you are not the intended recipient
>> of this message you are hereby notified that you must not disseminate,
>> copy or take any action with respect to it.
>>
>> If you have received this message in error please notify
>> HATCH immediately via mailto:MailAdmin@hatch.ca.
>>
>
>
Message 11
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| Subject: | Voice annunciation |
--> AeroElectric-List message posted by: "Glen Matejcek" <aerobubba@earthlink.net>
Hi Gordon-
Funny you should mention 73's- that's my rather tenuous source of income
at the moment. Of course, I've only ever read about the clacker and not
actually heard it....
BTW, there was a certain British turbo prop whose overspeed warning sounds
precisely like a McDonalds 'the french fries are done' warning... or so
I'm told...
Do Not Archive Under Any Circumstances!
Glen Matejcek
aerobubba@earthlink.net
Message 12
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| Subject: | Re: What is this device? |
--> AeroElectric-List message posted by: rv-9a-online <rv-9a-online@telus.net>
It appears to be a high frequency decoupling capacitor, used to reduce
conducted interferece. Was it near an instrument?
Vern Little
Hal Kempthorne wrote:
>--> AeroElectric-List message posted by: Hal Kempthorne <hal_kempthorne@sbcglobal.net>
>
>
>What the heck is this part? It is red, about half an inch square and about 1/16th
thick plastic with two leads .
>
>Marked
>
>ERIE
>
>3.3 M
>
>100V
>
>
>Found connect from power bus to ground.
>
>hal
>
>
>
>
Message 13
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| Subject: | Re: Intercom Problems in my RV-4 |
--> AeroElectric-List message posted by: Earl_Schroeder <Earl_Schroeder@juno.com>
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Message 14
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| Subject: | Re: electric gyros |
--> AeroElectric-List message posted by: Robert McCallum <robert.mccallum2@sympatico.ca>
No, it means that neither must be wired with a wire SMALLER than the
fuse or breaker is capable of protecting. You can use a wire as large
as you wish. It would be rather silly and heavy but if you found some
way to achieve the connections you could theoretically wire your dome
light with #2 wire, your intercom with #20 and protect both with a
single 5 amp fuse. As long as the smallest wire connected in the group
is properly protected by the fuse you are fine.
Bob McC
John Swartout wrote:
>--> AeroElectric-List message posted by: "John Swartout" <jgswartout@earthlink.net>
>
>So, if you are protecting two circuits with one breaker, for instance,
>dome light and intercom, does that mean that both must be wired with the
>same size wire? Or at least neither wired with a bigger wire than the
>c/b is adequate to protect?
>
>
Message 15
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| Subject: | Re: electric gyros |
--> AeroElectric-List message posted by: "Jeff Dowling" <shempdowling@earthlink.net>
I have a 5 amp cb on my electric Bob dimmer circuit. I dont remember what
size wire I have running from the breaker to the dimmer but I believe I have
24 or maybe even 28 running to the little lights Vans sells. Would a direct
short in one of these small wires trip the 5 amp c.b.?
Shemp/Jeff Dowling
RV-6A, N915JD
165 hours
Chicago/Louisville
----- Original Message -----
From: "Robert McCallum" <robert.mccallum2@sympatico.ca>
Subject: Re: AeroElectric-List: electric gyros
> --> AeroElectric-List message posted by: Robert McCallum
> <robert.mccallum2@sympatico.ca>
>
> No, it means that neither must be wired with a wire SMALLER than the
> fuse or breaker is capable of protecting. You can use a wire as large
> as you wish. It would be rather silly and heavy but if you found some
> way to achieve the connections you could theoretically wire your dome
> light with #2 wire, your intercom with #20 and protect both with a
> single 5 amp fuse. As long as the smallest wire connected in the group
> is properly protected by the fuse you are fine.
>
> Bob McC
>
> John Swartout wrote:
>
>>--> AeroElectric-List message posted by: "John Swartout"
>><jgswartout@earthlink.net>
>>
>>So, if you are protecting two circuits with one breaker, for instance,
>>dome light and intercom, does that mean that both must be wired with the
>>same size wire? Or at least neither wired with a bigger wire than the
>>c/b is adequate to protect?
>>
>>
>
>
>
Message 16
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--> AeroElectric-List message posted by: "Jim Stone" <jsto1@tampabay.rr.com>
Yes, any short with a resistance less then 2.4 ohms should trip the
breaker. The time may very depending on the actual resistance.
Crossing bare wires have very low resistance, hense the sparks. Basic
Ohms law: volts = current times resistance.
The wire size and material effects its resistance. Here's an
interesting web site if you want to get more precise.
http://www.redbinary.com/electrist_doc_Drop.php
Jim Stone
Jabiru J450 N450SJ
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jeff
Dowling
Subject: Re: AeroElectric-List: electric gyros
--> AeroElectric-List message posted by: "Jeff Dowling"
--> <shempdowling@earthlink.net>
I have a 5 amp cb on my electric Bob dimmer circuit. I dont remember
what
size wire I have running from the breaker to the dimmer but I believe I
have
24 or maybe even 28 running to the little lights Vans sells. Would a
direct
short in one of these small wires trip the 5 amp c.b.?
Shemp/Jeff Dowling
RV-6A, N915JD
165 hours
Chicago/Louisville
----- Original Message -----
From: "Robert McCallum" <robert.mccallum2@sympatico.ca>
Subject: Re: AeroElectric-List: electric gyros
> --> AeroElectric-List message posted by: Robert McCallum
> <robert.mccallum2@sympatico.ca>
>
> No, it means that neither must be wired with a wire SMALLER than the
> fuse or breaker is capable of protecting. You can use a wire as large
> as you wish. It would be rather silly and heavy but if you found some
> way to achieve the connections you could theoretically wire your dome
> light with #2 wire, your intercom with #20 and protect both with a
> single 5 amp fuse. As long as the smallest wire connected in the group
> is properly protected by the fuse you are fine.
>
> Bob McC
>
> John Swartout wrote:
>
>>--> AeroElectric-List message posted by: "John Swartout"
>><jgswartout@earthlink.net>
>>
>>So, if you are protecting two circuits with one breaker, for instance,
>>dome light and intercom, does that mean that both must be wired with
>>the same size wire? Or at least neither wired with a bigger wire than
>>the c/b is adequate to protect?
>>
>>
>
>
>
Message 17
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| Subject: | Re: electric gyros |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
It will trip the breaker, but... It will also make the
wire very hot and maybe melt the insulation. The chart
on Bob's site (or out of his book) shows that you get a
10 deg C rise by running 5A through a 22g wire. Figure
that you'll get much more using 24g. Looking around, I
found a chart that shows 26g wire will rise 60deg C over
ambient with 5A. Also figure that during the time that
it takes the breaker to trip, the current is MUCH higher.
Regards,
Matt-
> --> AeroElectric-List message posted by: "Jeff Dowling"
> <shempdowling@earthlink.net>
>
> I have a 5 amp cb on my electric Bob dimmer circuit. I dont remember
> what size wire I have running from the breaker to the dimmer but I
> believe I have 24 or maybe even 28 running to the little lights Vans
> sells. Would a direct short in one of these small wires trip the 5 amp
> c.b.?
>
> Shemp/Jeff Dowling
> RV-6A, N915JD
> 165 hours
> Chicago/Louisville
>
> ----- Original Message -----
> From: "Robert McCallum" <robert.mccallum2@sympatico.ca>
> To: <aeroelectric-list@matronics.com>
> Subject: Re: AeroElectric-List: electric gyros
>
>
>> --> AeroElectric-List message posted by: Robert McCallum
>> <robert.mccallum2@sympatico.ca>
>>
>> No, it means that neither must be wired with a wire SMALLER than the
>> fuse or breaker is capable of protecting. You can use a wire as large
>> as you wish. It would be rather silly and heavy but if you found some
>> way to achieve the connections you could theoretically wire your dome
>> light with #2 wire, your intercom with #20 and protect both with a
>> single 5 amp fuse. As long as the smallest wire connected in the group
>> is properly protected by the fuse you are fine.
>>
>> Bob McC
>>
>> John Swartout wrote:
>>
>>>--> AeroElectric-List message posted by: "John Swartout"
>>><jgswartout@earthlink.net>
>>>
>>>So, if you are protecting two circuits with one breaker, for instance,
>>> dome light and intercom, does that mean that both must be wired with
>>> the same size wire? Or at least neither wired with a bigger wire than
>>> the c/b is adequate to protect?
>>>
>>>
>>
>>
>>
>
>
Message 18
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| Subject: | Re: electric gyros |
--> AeroElectric-List message posted by: Robert McCallum <robert.mccallum2@sympatico.ca>
Probably, if the wire is #22 or #24. If it's #28 (unlikely) then it's
quite possible the wire will "blow" before the breaker trips in a
shorted situation. The recommended minimum wire size for 5 amps under
"most" conditions is #22. If you are using breakers as opposed to fuses
then the time lag for a breaker to trip might heat your #26 or #28 wire
to well beyond the insulation melting point before the breaker gets
around to tripping.
Bob McC
Jeff Dowling wrote:
>--> AeroElectric-List message posted by: "Jeff Dowling" <shempdowling@earthlink.net>
>
>I have a 5 amp cb on my electric Bob dimmer circuit. I dont remember what
>size wire I have running from the breaker to the dimmer but I believe I have
>24 or maybe even 28 running to the little lights Vans sells. Would a direct
>short in one of these small wires trip the 5 amp c.b.?
>
>Shemp/Jeff Dowling
>RV-6A, N915JD
>165 hours
>Chicago/Louisville
>
>
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