Today's Message Index:
----------------------
1. 04:31 AM - Re: EMI From Seat Heaters and Other Questions (Alec Myers)
2. 04:42 AM - Re: EMI From Seat Heaters and Other Questions (Alec Myers)
3. 05:07 AM - Re: EMI From Seat Heaters and Other Questions (Alec Myers)
4. 08:43 AM - Re: Z-13/8 and SD-8 (user9253)
5. 08:56 AM - Re: SD-20/SD-60 Question (Bill Watson)
6. 10:16 AM - Re: SD-20/SD-60 Question (Robert L. Nuckolls, III)
7. 11:00 AM - Conduit and adding wires (Bill Schertz)
8. 11:22 AM - Rotax 912iS questions (GTH)
9. 11:49 AM - Re: Rotax 912iS questions (Charlie England)
10. 02:22 PM - EMI From Seat Heaters and Other Questions (Owen Baker)
11. 03:29 PM - Re: SD-20/SD-60 Question (William Hunter)
12. 03:32 PM - Re: EMI From Seat Heaters and Other Questions (William Hunter)
13. 04:52 PM - Re: EMI From Seat Heaters and Other Questions (Charlie England)
14. 06:29 PM - Re: EMI From Seat Heaters and Other Questions (Robert L. Nuckolls, III)
15. 09:18 PM - Re: EMI From Seat Heaters and Other Questions (Buckaroo Banzai)
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Subject: | Re: EMI From Seat Heaters and Other Questions |
Someone has their units mixed up here. BTU is a measure of energy. Heaters a
re measured in BTU/hour. (Like the difference between joules and watts). 480
W is 1638BTU/h, and 8000BTU/h is 2344W so the two figures given don't seem t
o agree. The former seems more reasonable than the latter for this unit.
On Jan 3, 2017, at 23:50, Eric Page <edpav8r@yahoo.com> wrote:
> On Jan 3, 2017, at 6:20 PM, William Hunter <billhuntersemail@gmail.com> wr
ote:
> QUESTION 4: How much heat would a small 12 VDC electric element heater sy
stem realistically put out? This is the one we have been discussing it is de
signed for a RV unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p
/sd12-4000.htm
>
At the risk of being pedantic, I'm not sure how one would answer this other t
han to quote the product's specifications and explain the units.
The description says this heater rated for 8,016 British Thermal Units (BTUs
). A BTU is the amount of energy it takes to heat one pound of water (about
16 fl oz, or two cups) by one degree Fahrenheit.
So, the heat energy this thing puts out could heat a 4-ton tank of water (ap
prox 960 US gal) by one deg F in one hour. Or, to use numbers that are a bi
t more meaningful, heat about 96 gal of water by 10 deg F in one hour. Stil
l not a very helpful comparison.
The specs say it draws 480W (40A at 12V). It looks like the blower motor ac
counts for 15W (1.25A) of that total, which leaves 465W (38.75A) for the hea
ting elements. That's a decent amount of heat, but compare that figure agai
nst a typical small domestic space heater that we're all familiar with: they
're commonly rated at 1,500W. The first three search results for "hair drye
r" on Amazon are rated at 1,875W!
Recommendations vary between 20 and 60 BTU/sq ft for heating a home, dependi
ng on your climate region. If you assume a middle value of 40 BTU/sq ft, th
en 8,000 BTU would be about right for a 200 sq ft room (in a home insulated t
o code).
Whether that kind of analysis translates to airplanes, or if 8,000 BTU is ad
equate for a light plane cockpit flying through freezing air are interesting
questions. How warm is warm enough?
Eric
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Subject: | Re: EMI From Seat Heaters and Other Questions |
One might also point out that trying to heat a space from a 12v supply is li
ke filling a swimming pool from a garden hose. Don't expect too much - there
's a reason that where the aviation community can't use exhaust muff heating
systems (cabin twins, for instance) they don't try electric, they use Janit
rol heaters.
On Jan 3, 2017, at 23:50, Eric Page <edpav8r@yahoo.com> wrote:
> On Jan 3, 2017, at 6:20 PM, William Hunter <billhuntersemail@gmail.com> wr
ote:
> QUESTION 4: How much heat would a small 12 VDC electric element heater sy
stem realistically put out? This is the one we have been discussing it is de
signed for a RV unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p
/sd12-4000.htm
>
At the risk of being pedantic, I'm not sure how one would answer this other t
han to quote the product's specifications and explain the units.
The description says this heater rated for 8,016 British Thermal Units (BTUs
). A BTU is the amount of energy it takes to heat one pound of water (about
16 fl oz, or two cups) by one degree Fahrenheit.
So, the heat energy this thing puts out could heat a 4-ton tank of water (ap
prox 960 US gal) by one deg F in one hour. Or, to use numbers that are a bi
t more meaningful, heat about 96 gal of water by 10 deg F in one hour. Stil
l not a very helpful comparison.
The specs say it draws 480W (40A at 12V). It looks like the blower motor ac
counts for 15W (1.25A) of that total, which leaves 465W (38.75A) for the hea
ting elements. That's a decent amount of heat, but compare that figure agai
nst a typical small domestic space heater that we're all familiar with: they
're commonly rated at 1,500W. The first three search results for "hair drye
r" on Amazon are rated at 1,875W!
Recommendations vary between 20 and 60 BTU/sq ft for heating a home, dependi
ng on your climate region. If you assume a middle value of 40 BTU/sq ft, th
en 8,000 BTU would be about right for a 200 sq ft room (in a home insulated t
o code).
Whether that kind of analysis translates to airplanes, or if 8,000 BTU is ad
equate for a light plane cockpit flying through freezing air are interesting
questions. How warm is warm enough?
Eric
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Subject: | Re: EMI From Seat Heaters and Other Questions |
Last post for now, I promise: the Janitrol approved for installation in a (4
seat) Cessna 170 is 25000BTU/h which is 7.3kW. Compare 500w...
On Jan 4, 2017, at 07:41, Alec Myers <alec@alecmyers.com> wrote:
One might also point out that trying to heat a space from a 12v supply is li
ke filling a swimming pool from a garden hose. Don't expect too much - there
's a reason that where the aviation community can't use exhaust muff heating
systems (cabin twins, for instance) they don't try electric, they use Janit
rol heaters.
On Jan 3, 2017, at 23:50, Eric Page <edpav8r@yahoo.com> wrote:
> On Jan 3, 2017, at 6:20 PM, William Hunter <billhuntersemail@gmail.com> wr
ote:
> QUESTION 4: How much heat would a small 12 VDC electric element heater sy
stem realistically put out? This is the one we have been discussing it is de
signed for a RV unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p
/sd12-4000.htm
>
At the risk of being pedantic, I'm not sure how one would answer this other t
han to quote the product's specifications and explain the units.
The description says this heater rated for 8,016 British Thermal Units (BTUs
). A BTU is the amount of energy it takes to heat one pound of water (about
16 fl oz, or two cups) by one degree Fahrenheit.
So, the heat energy this thing puts out could heat a 4-ton tank of water (ap
prox 960 US gal) by one deg F in one hour. Or, to use numbers that are a bi
t more meaningful, heat about 96 gal of water by 10 deg F in one hour. Stil
l not a very helpful comparison.
The specs say it draws 480W (40A at 12V). It looks like the blower motor ac
counts for 15W (1.25A) of that total, which leaves 465W (38.75A) for the hea
ting elements. That's a decent amount of heat, but compare that figure agai
nst a typical small domestic space heater that we're all familiar with: they
're commonly rated at 1,500W. The first three search results for "hair drye
r" on Amazon are rated at 1,875W!
Recommendations vary between 20 and 60 BTU/sq ft for heating a home, dependi
ng on your climate region. If you assume a middle value of 40 BTU/sq ft, th
en 8,000 BTU would be about right for a 200 sq ft room (in a home insulated t
o code).
Whether that kind of analysis translates to airplanes, or if 8,000 BTU is ad
equate for a light plane cockpit flying through freezing air are interesting
questions. How warm is warm enough?
Eric
Message 4
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Subject: | Re: Z-13/8 and SD-8 |
Bob, thanks for that explanation.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=464694#464694
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Subject: | Re: SD-20/SD-60 Question |
On 1/3/2017 9:55 PM, William Hunter wrote:
>
> I am running a SD-60 and a LR3C-14 Voltage Regulator on one bus with
> its own battery and a SD-20 with its own LR3C-14 Voltage Regulator on
> the second bus with its own battery. The engine is a Lycoming IO-540.
>
I have been operating an RV10 with a Z-14, LR3Cs, an SD40 and SD20, all
on an IO-540. A Z-14 is what you are describing.
>
> QUESTION 1: I intend to operate my two electrical systems isolated
> with a bus tie that will be used for engine start only and then untied
> afterwards. What happens if I forget to untie the two busses after
> engine start and both the SD-60 and the SD-20 are providing current to
> the combined system? Do they share the load equally on the combined
> system? What happens should the system load reach 50 AMPS? Does the
> SD-20 simply max out at 20 AMPS and then the SD-60 picks up the rest
> of the 30 AMPS?
>
Operationally, the idea is to use the systems tied for the start, then
untie them for flight. I've run them both ways, 50:50, over 800 hours.
No problems either way but I can't tell you exactly what was charging
what, when, due a voltage measurement problem (see way below).
A big reason you run them split is so you can detect any problems. I
recently 'lost' the SD-40 in IMC - low voltage light came on and bus
voltage dropped to battery levels on the one bus. Nothing popped or
anything so I simply cross-tied the buses and turned off the Alt/Batt
switch on the SD-40 side. The SD-20 kept the voltage at an acceptable,
constant level until the flight was completed. (the problem on the SD-40
bus turned out to a degraded connection somewhere in the LR3-switch-bus
circuit that detects field voltage. Executing B&C LR3 troubleshooting
procedure identified the problem. All connections were physically reset
and problem resolved)
>
> QUESTION 2: If I do remember to untie the bussesWhat happens to the
> single system when there is a temporary current spike on that isolated
> system? Example: Should the alternator be running at 90 percent of
> its capacity and then the electric landing gear hydraulic pump cycles
> and draws another 25-30 AMPS. Does the voltage regulator simply limit
> the alternator output to its max output of 60/20 AMPS and then the
> system draws down the battery during the short time the gear pump is
> active or does the voltage regulator deactivate the SD-60 requiring a
> reset?
>
Just like a single bus/alt/batt, it draws on the battery but you won't
even notice.
>
> QUESTION 3: How much output does the SD-60 and the SD-20 really put
> out both at idle and at cruise RPM? I heard that the belt driven
> alternator will put out full production at low RPM however the SD-20
> will only put out lower production at low RPM and only reach its full
> rated production at max RPM?
>
Yes, the SD-20 will put out considerably less than 20amps at idle.
Doesn't really matter in my experience
Voltage Measurement: I created a problem with how I measured bus
voltages. I have a GRT panel with (3) EFISs and (1) EIS. I took one
voltage measurement from the EIS and the other from the EFIS, and then
displayed the 2 voltages on the EFIS. This was easy since the EFISs
were on 1 bus and the EIS on the other. In both cases I was getting the
voltage level of the feeds for each system. However the EFISs represent
a significant load and the voltage there was about .6 volts less than
bus voltage. On the other hand, the EIS is a very low, constant load
device and the voltage there more or less was equal to bus voltage.
Many problems resulted from this. The solution is to get your 2 bus
measurements from places that match bus voltages.
Load Balancing: Distinguish between constant loads and temporary
loads. My understanding is that you generally balance for constant
loads (Powered on panel devices, strobes, running lights) and rely on
your excess capacity and battery for the others (gear, landing lights,
radio transmit, engine start). I got a bit fancy and started with too
many constant loads on the SD-20. Though the SD-20 will run everything
on both buses in daytime cruise and keep the battery fully charged.
Charging voltage levels: If you are using AGM batteries (PC680s here) be
careful about low bus voltages. 14.2 is a good minimum and you should
see at least 14 on both buses at shutdown. Anything less means that
your battery is being stored at less than full charge and that will
shorten its life. Any shutdown voltage level of 13.x is going to cost
you extra battery money in my experience.
Bill "wishing for FIKI" Watson
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Subject: | Re: SD-20/SD-60 Question |
I am running a SD-60 and a LR3C-14 Voltage Regulator on one bus with
its own battery and a SD-20 with its own LR3C-14 Voltage Regulator on
the second bus with its own battery. The engine is a Lycoming IO-540.
Okay, Figure Z-14 . . .
QUESTION 1: I intend to operate my two electrical systems isolated
with a bus tie that will be used for engine start only and then
untied afterwards. What happens if I forget to untie the two busses
after engine start and both the SD-60 and the SD-20 are providing
current to the combined system? Do they share the load equally on
the combined system? What happens should the system load reach 50
AMPS? Does the SD-20 simply max out at 20 AMPS and then the SD-60
picks up the rest of the 30 AMPS?
Not necessarily. Both regulators should be set for
optimal BATTERY maintenance (14.2 to 14.6 volts).
It's practically impossible to set them to the same
voltage. Hence, while paralleled, the alternator
with the slightly higher setting will 'hog' the
load until such time as it maxes out, bus voltage
falls until the alternator with the lower set-point
picks up the difference.
QUESTION 2: If I do remember to untie the busses . . .
How would this happen? If wired per the published
drawing, the crossfeed contactor is automatically
closed when a SPRING LOADED switch is moved to
START position. This gets you two batteries for
cranking while illuminating a CROSSFEED WARN
light. When the engine starts, the switch is
released, the contactor opens, the light goes
out. Nothing to 'forget'.
Emacs!
What happens to the single system when there is a temporary current
spike on that isolated system? Example: Should the alternator be
running at 90 percent of its capacity and then the electric landing
gear hydraulic pump cycles and draws another 25-30 AMPS. Does the
voltage regulator simply limit the alternator output to its max
output of 60/20 AMPS and then the system draws down the battery
during the short time the gear pump is active or does the voltage
regulator deactivate the SD-60 requiring a reset?
Not sure what the concern is here. First, how do
you expect to normally load either alternator so
heavily? Both sides should be designed to achieve
25% or so of headroom on the alternator for battery
charging.
But even if the inrush current from a pump motor
exceeds an alternator's rated capacity, the bus
voltage sags, the battery picks up the difference,
and all returns to normal after the event . . . which
is generally over in tens of milliseconds. No big
deal.
QUESTION 3: How much output does the SD-60 and the SD-20 really put
out both at idle and at cruise RPM? I heard that the belt driven
alternator will put out full production at low RPM however the SD-20
will only put out lower production at low RPM and only reach it's
full rated production at max RPM?
Generally true. Don't go by what you HEAR . . . go
get the specs from the folks who design, manufacture,
sell and support the systems. Generally speaking,
B&C belt driven alternators DO run fast . . . unlike
alternators deliberately slowed by installation of
larger pulleys (to save bearings), the B&C alternators
(and most others) produce a substantial fraction of
rated output at taxi speeds.
The SD-20 is mechanically crippled by installation on
a drive pad with a max rpm on the order of 4K . . . LESS
than minimum speed for full output from the 40A core
from which the SD-20 is manufactured.
Have offered that, it behooves every builder to KNOW
what the in flight running loads are on ANY alternators.
To KNOW what headroom is available to recharge the
companion battery. To KNOW what energy levels are
stored in any combination of batteries.
Figure Z-14 offers a tall fire-wall against failures
but it does not negate the value of discovering and
understanding EVERYTHING there is to know about how
all the pieces fit together along with the effect
any single failure might have on in-flight systems
operations.
Bob . . .
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Subject: | Conduit and adding wires |
One other technique for adding a wire to an existing conduit if you don't
have the embedded string is to take a length of 1/4" polyethylene tubing,
run it down the existing conduit (may have to occasionally turn it) it is
stiff enough to allow you to install it, then run the wire into the tube,
fasten the far end and pull the tube back out. The slippery nature of the
tubing makes pushing the wire through easy,.
Bill Schertz
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Subject: | Rotax 912iS questions |
Hi all,
Presently considering the wiring of a Rotax 912iS in a friend's
composite project.
The engine features a digital fuel injection with high pressure fuel
pumps, digital control "lanes", backup power circuit, dual alternator
with control box etc.
The Rotax Installation manual calls for a certain number of panel switches :
Pump A and B switches (permanent) : 10 A each
Lane A & B switches (permanent) : 7.5 A each
Engine Control Unit start power switch (momentary) : 20 A
Backup battery switch (permanent) : 20 A
QUESTION : is it advisable to bring such heavy current carrying wires to
the panel, or would it be preferable to use relays to control the system ?
Any input appreciated,
Thanks in advance,
--
Best regards,
Gilles
http://contrails.free.fr
http://lapierre.skunkworks.free.fr
Message 9
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Subject: | Re: Rotax 912iS questions |
On 1/4/2017 1:21 PM, GTH wrote:
>
> Hi all,
>
> Presently considering the wiring of a Rotax 912iS in a friend's
> composite project.
>
> The engine features a digital fuel injection with high pressure fuel
> pumps, digital control "lanes", backup power circuit, dual alternator
> with control box etc.
>
> The Rotax Installation manual calls for a certain number of panel
> switches :
>
> Pump A and B switches (permanent) : 10 A each
>
> Lane A & B switches (permanent) : 7.5 A each
>
> Engine Control Unit start power switch (momentary) : 20 A
>
> Backup battery switch (permanent) : 20 A
>
> QUESTION : is it advisable to bring such heavy current carrying wires
> to the panel, or would it be preferable to use relays to control the
> system ?
>
> Any input appreciated,
>
> Thanks in advance,
>
>
> --
> Best regards,
> Gilles
> http://contrails.free.fr
> http://lapierre.skunkworks.free.fr
For me, the decisions were based both on overall weight, and
complexity/reliability (yes, I know they aren't necessarily the same
thing, but can be related).
How much weight (length has a big influence) will using the heavier
gauge wire add, vs the added weight of the relay? How much reliability
will you sacrifice by adding a relay and all the extra terminations
required?
Even 20 A is not that big a deal for the proper switch. Going bigger
than that, a relay starts to look more attractive, especially since the
automotive world now makes fairly light weight, high current relays
available for very reasonable prices.
Charlie
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Subject: | EMI From Seat Heaters and Other Questions |
1/4/2017
Hello Bill Hunter, I could not find enough space under the engine
cowling to put a heat muff on the exhaust system of my KIS TR-1 airplane
powered by a Continental Motors IO-240 B9B engine.
I initially tried to use an recreational vehicle heater similar to your:
http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm
It generated about as much heat as waving a lighted cigarette around in
the cockpit. Also it generated noise on the radio. Totally useless.
My solution was electrically heated clothing like the motorcyclists and
the snowmobile riders use. My brand was Gerbings bought several years
ago which has worked great. That company=99s recent history is
shaky so shop around before you buy.
OC
=============
Time: 06:23:06 PM PST US
From: "William Hunter" <billhuntersemail@gmail.com>
Subject: AeroElectric-List: EMI From Seat Heaters and Other Questions
Hi AeroElectric Cyber Friends!!!
I figured I would bounce these questions off of the folks on this forum.
Over at the Velocity Aircraft Forum we have some questions with respect
to
EMI from 12 VDC supplemental cabin heat systems such as heated seats,
heated
blankets (such as an electric blanket that you plug into the cigarette
lighter), and/or a 12 volt electric heating element heater.
QUESTION 1: Would the heat blanket/seat system affect the magnetometer
on
the aircraft? The 12 VDC electric heater has a motor and an element so
that
certainly might cause issues. If so how far away would you consider it
the
reasonable distance from the magnetometer to the heated element in the
blanket/seat?
QUESTION 2: If the heated seat would cause EMI, is it possible to
mitigate
the EMI by "polarizing" the seat inserts (placing one element in one
direction and the other in the opposite direction? This is the heated
seat
kit I bought for my aircraft:
<https://www.amazon.com/Water-Carbon-Premium-Heated-Seats/dp/B00AKEVNP2/r
ef
sr_1_10?ie=UTF8&qid=1483494619&sr=8-10&keywords=car%2Bheated%2Bse
ats&th=1>
https://www.amazon.com/Water-Carbon-Premium-Heated-Seats/dp/B00AKEVNP2/re
f=s
r_1_10?ie=UTF8&qid=1483494619&sr=8-10&keywords=car%2Bheated%2Bsea
ts&th=1
QUESTION 3: Would an electric seat/blanket cause radio noise? If so
what
can one do to mitigate the noise?
QUESTION 4: How much heat would a small 12 VDC electric element heater
system realistically put out? This is the one we have been discussing it
is
designed for a RV unit:
<http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm>
http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm
Does anybody happen to have any experience with this particular unit and
to
see if it's worth the cost / weight penalty involved in hauling this
thing
around. I was thinking of installing this under the instrument panel and
using it as a defroster by directing the "heated" air toward the
windshield.
We are in a "heated discussion" on how to add a heat source to the
airplane.
The only heat in the velocity airplane design is an oil cooler mounted
in
the nose and that air/oil heat exchanger is used for cabin heat.the
problem
being that outside air is blown through the oil cooler and into the
cabin
and naturally during cold months the OAT is significantly cold and
therefore
the heat increase is not very efficient plus the fact that our air
cooled
engines may not be producing that much oil temperature to begin with so
we
are dreaming of ways to supplement our interior heat.
Any suggestions/feedback/experience would be greatly appreciated!!!
THANKS!!!
Bill Hunter
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Subject: | SD-20/SD-60 Question |
Joe and Bob,
I am VERY GRATEFUL for your help on this!!!
>Okay, Figure Z-14 . . .
Yes exactly.I stole that idea from the best source I could find. I did not
go with the auto bus tie option however.
>Both sides should be designed to achieve 25% or so of headroom on the
alternator for battery
charging.
Can you all PLEASE check my homework on the current draw of the proposed
equipment on each system?
Naturally not all of these items will be running at the same time so it is
hard to try to figure out what the actual steady state load will be.
EXAMPLE: On hot days I will need the turbo intercooler electric fans but no
pitot heat nor heated seats and vice versa. Communications radios on
receive mode draw very little however when transmitting they draw 3 AMPS for
only that time.
I will be running two Dynon SV-1000s and each will be powered by its onside
independent electrical system.
Red System Loads (SD-20):
The left system with the SD-20 is called "RED" (because there is a red light
on the left wingtip).
CB NAME AMP ITEM ON RED (PILOT SIDE)
BUS BAR
VOLT REG SENSE 2 LR3C-14 Voltage Regulator BUS VOLTAGE SENSE
VOLT REG FIELD 5 VOLTAGE REGULATOR FIELD
EFIS 5 Pilot side EFIS system
SV-D1000 10" SKYVIEW DISPLAY 3.5amp
SV-GPS-250 GPS MODULE
0.10amp
SV-BAT-320 1.00 amp (only when
at max charge)
SV-ADAHRS-200 0.15amp
USB WiFi ADAPTER 0.10amp
SV-ARINC-429 0.10amp
SV-KNOB-PANEL
0.07 amp
SV-AP-PANEL 0.05 amp
SV-EMS220
0.11amp
SV COM 5 SV-COM-425
0.2amp continuous in RCV mode
3 amp only during XMT
SV-AP SERVO 5 SV-AP SERVO
Pitch servo 2 amps only when moving at MAX torque
Roll servo 2 amps only when moving at MAX torque
SV-AP POWER 3 SV-AP UNIT
AP control box less than 3 amps
TAXI LIGHT 5 TAXI LIGHT IN NOSE
ENG FAN 2 ELECTRIC TURBO
INTERCOOLER COOLING FANS ACCY FEED
This CB powers the accessory power for the relays only. There are two
engine cooling fans mounted below the turbocharger intercooler and there are
two relays (one for each fan) attached to the battery box and each relay
needs a 12V signal for accessory on and then it also needs a ground signal
to close the relay contacts that power the fans. The ground signal is
provided by switched ground. When the relay closes the fans get their power
feed directly from the GREEN battery output through a 30 AMP inline fuse.
The Intercooler fans provide supplemental ground and climb cooling to the
intercooler and engine and therefore this system is not required for flight
GREEN BUS SD-60
The right system with the SD-60 is called "GREEN" (you get the idea).
CB NAME AMP ITEM ON MAIN BUS BAR
VOLT REG SENSE 2 LR3C-14 Voltage Regulator BUS VOLTAGE SENSE
VOLT REG FIELD 5 VOLTAGE REGULATOR FIELD
EFIS 5 (All these items are powered
from the #2 Skyview)
SV-D1000 10" SKYVIEW DISPLAY 3.5amp
SV-GPS-250 GPS MODULE
0.10amp
SV-BAT-320 1.00 amp
SV-ADAHRS-200 0.15amp
SV-ARINC-429 0.10amp
SV-KNOB-PANEL
0.07 amp
SV-AP-PANEL 0.05 amp
SV-EMS220
0.11amp
USB WiFi ADAPTER
0.10amp
FUEL PUMP 10 ELECTRIC FUEL PUMP
PITOT 10 10.0amp max @ max heat
START 5 STARTER SOLENOID
GEAR CONTROL 5 Gear Controller circuitry 18 AWH wire
GEAR HYD 30 Electro-Hydraulic pump for retractable
gear actuation
STROBE 10 WHELEN HDACF 01-0770028-05
LAND LIGHT 10 HID Landing Light plus two LED landing
lights
MISC LTS 5 INTERIOR LEDS AND OTHER LED MISC
LIGHTS
USB 10 USB CHARGER AND CIGARETTE
LIGHTER SOCKET
FUEL QTY 2 PRINCETON CAPACITANCE PROBES (two
probes total)
NAV 5 INCANDESCENT LIGHTS
HEATED SEATS 10 FOUR SEATS IN THE AIRPLANE WILL BE HEATED.
THIS CB IS FOR THE ACCESSORY
CONTROL ONLY. THE SEAT
HEATERS HAVE THEIR OWN 10 AMP MINI CB THAT IS
CONNECTED TO THE GREEN BUS
BAR.
AVIONICS BUS YELLOW:
The Avionics bus will be normally powered by the GREEN Bus through a
dedicated Honeywell LT-001 ON/OFF switch.
During abnormal operations after manual load shedding the Avionics Bus can
be powered by the RED Bus through a dedicated Honeywell LT-001 ON/OFF
switch.
CB NAME AMP ITEM ON AVIONICS BUS BAR
GARMIN COM 10 GARMIN GNS650 Comm Connector .45A
continuous 5.66A Max when transmitting
GARMIN NAV 7.5 GARMIN GNS650 Nav Connector .6A
continuous
1.16A Max
Main Connector 1.6A continuous 2.8A Max
AUDIO 3 SL-15
0.350amp typ 1.5amp max
XPNDR 5 SV-XPNDR-261
0.4amp
ADS-B 5 SV-ADSB-470
0.2amp
THANKS AGAIN!!!
..
Cheers!!!
Bill Hunter
Mobile 408-464-1902
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Wednesday, January 4, 2017 10:15 AM
Subject: Re: AeroElectric-List: SD-20/SD-60 Question
I am running a SD-60 and a LR3C-14 Voltage Regulator on one bus with its own
battery and a SD-20 with its own LR3C-14 Voltage Regulator on the second bus
with its own battery. The engine is a Lycoming IO-540.
Okay, Figure Z-14 . . .
QUESTION 1: I intend to operate my two electrical systems isolated with a
bus tie that will be used for engine start only and then untied afterwards.
What happens if I forget to untie the two busses after engine start and both
the SD-60 and the SD-20 are providing current to the combined system? Do
they share the load equally on the combined system? What happens should the
system load reach 50 AMPS? Does the SD-20 simply max out at 20 AMPS and
then the SD-60 picks up the rest of the 30 AMPS?
Not necessarily. Both regulators should be set for
optimal BATTERY maintenance (14.2 to 14.6 volts).
It's practically impossible to set them to the same
voltage. Hence, while paralleled, the alternator
with the slightly higher setting will 'hog' the
load until such time as it maxes out, bus voltage
falls until the alternator with the lower set-point
picks up the difference.
QUESTION 2: If I do remember to untie the busses . . .
How would this happen? If wired per the published
drawing, the crossfeed contactor is automatically
closed when a SPRING LOADED switch is moved to
START position. This gets you two batteries for
cranking while illuminating a CROSSFEED WARN
light. When the engine starts, the switch is
released, the contactor opens, the light goes
out. Nothing to 'forget'.
What happens to the single system when there is a temporary current spike on
that isolated system? Example: Should the alternator be running at 90
percent of its capacity and then the electric landing gear hydraulic pump
cycles and draws another 25-30 AMPS. Does the voltage regulator simply
limit the alternator output to its max output of 60/20 AMPS and then the
system draws down the battery during the short time the gear pump is active
or does the voltage regulator deactivate the SD-60 requiring a reset?
Not sure what the concern is here. First, how do
you expect to normally load either alternator so
heavily? Both sides should be designed to achieve
25% or so of headroom on the alternator for battery
charging.
But even if the inrush current from a pump motor
exceeds an alternator's rated capacity, the bus
voltage sags, the battery picks up the difference,
and all returns to normal after the event . . . which
is generally over in tens of milliseconds. No big
deal.
QUESTION 3: How much output does the SD-60 and the SD-20 really put out
both at idle and at cruise RPM? I heard that the belt driven alternator
will put out full production at low RPM however the SD-20 will only put out
lower production at low RPM and only reach it's full rated production at max
RPM?
Generally true. Don't go by what you HEAR . . . go
get the specs from the folks who design, manufacture,
sell and support the systems. Generally speaking,
B&C belt driven alternators DO run fast . . . unlike
alternators deliberately slowed by installation of
larger pulleys (to save bearings), the B&C alternators
(and most others) produce a substantial fraction of
rated output at taxi speeds.
The SD-20 is mechanically crippled by installation on
a drive pad with a max rpm on the order of 4K . . . LESS
than minimum speed for full output from the 40A core
from which the SD-20 is manufactured.
Have offered that, it behooves every builder to KNOW
what the in flight running loads are on ANY alternators.
To KNOW what headroom is available to recharge the
companion battery. To KNOW what energy levels are
stored in any combination of batteries.
Figure Z-14 offers a tall fire-wall against failures
but it does not negate the value of discovering and
understanding EVERYTHING there is to know about how
all the pieces fit together along with the effect
any single failure might have on in-flight systems
operations.
Bob . . .
_____
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Message 12
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Subject: | EMI From Seat Heaters and Other Questions |
Thanks All for your time in contributing to this subject. I certainly
came to the right place.
DANGand I thought that a =9CBTU=9D was a form of
currency changing because I see BTU on my utility bill and my currency
changes from my account to the utility company account.
..
Cheers!!!
Bill Hunter
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alec
Myers
Sent: Wednesday, January 4, 2017 4:31 AM
Subject: Re: AeroElectric-List: EMI From Seat Heaters and Other
Questions
Someone has their units mixed up here. BTU is a measure of energy.
Heaters are measured in BTU/hour. (Like the difference between joules
and watts). 480W is 1638BTU/h, and 8000BTU/h is 2344W so the two figures
given don't seem to agree. The former seems more reasonable than the
latter for this unit.
On Jan 3, 2017, at 23:50, Eric Page <edpav8r@yahoo.com
<mailto:edpav8r@yahoo.com> > wrote:
On Jan 3, 2017, at 6:20 PM, William Hunter <billhuntersemail@gmail.com
<mailto:billhuntersemail@gmail.com> > wrote:
QUESTION 4: How much heat would a small 12 VDC electric element heater
system realistically put out? This is the one we have been discussing it
is designed for a RV unit:
http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm
At the risk of being pedantic, I'm not sure how one would answer this
other than to quote the product's specifications and explain the units.
The description says this heater rated for 8,016 British Thermal Units
(BTUs). A BTU is the amount of energy it takes to heat one pound of
water (about 16 fl oz, or two cups) by one degree Fahrenheit.
So, the heat energy this thing puts out could heat a 4-ton tank of water
(approx 960 US gal) by one deg F in one hour. Or, to use numbers that
are a bit more meaningful, heat about 96 gal of water by 10 deg F in one
hour. Still not a very helpful comparison.
The specs say it draws 480W (40A at 12V). It looks like the blower
motor accounts for 15W (1.25A) of that total, which leaves 465W (38.75A)
for the heating elements. That's a decent amount of heat, but compare
that figure against a typical small domestic space heater that we're all
familiar with: they're commonly rated at 1,500W. The first three search
results for "hair dryer" on Amazon are rated at 1,875W!
Recommendations vary between 20 and 60 BTU/sq ft for heating a home,
depending on your climate region. If you assume a middle value of 40
BTU/sq ft, then 8,000 BTU would be about right for a 200 sq ft room (in
a home insulated to code).
Whether that kind of analysis translates to airplanes, or if 8,000 BTU
is adequate for a light plane cockpit flying through freezing air are
interesting questions. How warm is warm enough?
Eric
Message 13
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Subject: | Re: EMI From Seat Heaters and Other Questions |
Well....That's kinda comparing apples to kumquats.
Ever driven a late model car with seat heaters? Hop in on a freezing
cold day, crank the engine, and with the seat heaters on, your body will
be warm before the engine coolant has gone up 2 degrees. All the heat
goes directly to your body core.
As an analogy, consider the radiant heaters used in a lot of workshops.
As long as they are pointed at the worker, the worker stays reasonably
warm even though the shop's air temp stays cold.
I suspect that twins had Janitrol heaters long before heated seats were
invented, or even a possibility (many generators from that era could
barely keep up with the electrical demands of the instrument panel). And
the current crop of cabin twins have them because those that can afford
them expect them to offer all the comforts of home; hang the expense and
inefficiency.
Charlie
On 1/4/2017 6:41 AM, Alec Myers wrote:
> One might also point out that trying to heat a space from a 12v supply
> is like filling a swimming pool from a garden hose. Don't expect too
> much - there's a reason that where the aviation community can't use
> exhaust muff heating systems (cabin twins, for instance) they don't
> try electric, they use Janitrol heaters.
>
> On Jan 3, 2017, at 23:50, Eric Page <edpav8r@yahoo.com
> <mailto:edpav8r@yahoo.com>> wrote:
>
> On Jan 3, 2017, at 6:20 PM, William Hunter <billhuntersemail@gmail.com
> <mailto:billhuntersemail@gmail.com>> wrote:
>>
>> QUESTION 4: How much heat would asmall 12 VDC electric element
>> heater system realistically put out? This is the one we have been
>> discussing it is designed for a RV unit:
>> http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm
>>
>
> At the risk of being pedantic, I'm not sure how one would answer this
> other than to quote the product's specifications and explain the units.
>
> The description says this heater rated for 8,016 British Thermal Units
> (BTUs). A BTU is the amount of energy it takes to heat one pound of
> water (about 16 fl oz, or two cups) by one degree Fahrenheit.
>
> So, the heat energy this thing puts out could heat a 4-ton tank of
> water (approx 960 US gal) by one deg F in one hour. Or, to use
> numbers that are a bit more meaningful, heat about 96 gal of water by
> 10 deg F in one hour. Still not a very helpful comparison.
>
> The specs say it draws 480W (40A at 12V). It looks like the blower
> motor accounts for 15W (1.25A) of that total, which leaves 465W
> (38.75A) for the heating elements. That's a decent amount of heat,
> but compare that figure against a typical small domestic space heater
> that we're all familiar with: they're commonly rated at 1,500W. The
> first three search results for "hair dryer" on Amazon are rated at 1,875W!
>
> Recommendations vary between 20 and 60 BTU/sq ft for heating a home,
> depending on your climate region. If you assume a middle value of 40
> BTU/sq ft, then 8,000 BTU would be about right for a 200 sq ft room
> (in a home insulated to code).
>
> Whether that kind of analysis translates to airplanes, or if 8,000 BTU
> is adequate for a light plane cockpit flying through freezing air are
> interesting questions. How warm is warm enough?
>
> Eric
Message 14
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Subject: | Re: EMI From Seat Heaters and Other Questions |
>
>I suspect that twins had Janitrol heaters long before heated seats
>were invented, or even a possibility (many generators from that era
>could barely keep up with the electrical demands of the instrument
>panel). And the current crop of cabin twins have them because those
>that can afford them expect them to offer all the comforts of home;
>hang the expense and inefficiency.
Janitrol and Southwind . . . both legacy icons
in cabin comfort in the air and especially on the
ground.
I picked up an old Southwind heater at a garage sale
some years back and was fascinated by the technology.
MUCH simpler than the gas fired heater in my VW van.
Dug up the patents on a few models . . . very slick.
Used engine vacuum to 'suck' fuel, provide 'draft'
and dispose of exhaust gasses. Glo plug for ignition.
Really slick. Combustion fuel/air pathway totally
closed. These were popular before my time but relatives
spoke highly of them. McCollum's name appears on dozens
of Southwind patents of that era . . . he was a
prolific inventor/developer.
My mentor (Ken Razak) and I puzzled over the practicality
of adapting a similar technology to compact cabin heaters
for the Ez series aircraft . . . using a venturi to produce
operating vacuum. It appeared doable but not without a
great deal of R&D . . . and the market was limited.
All light twins use gas heaters 'cause you just can't
get exhaust-muff heated air in from the wings. Further
if the airplane is pressurized, the cabin air side
of a gas heater lends itself to becoming part of the
pressure vessel.
Persons interested in reviewing this piece of automotive
history are welcome to download the data package at:
http://tinyurl.com/jy6potv
Bob . . .
---
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Message 15
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Subject: | EMI From Seat Heaters and Other Questions |
Have you considered a door in the fresh air inlet to the air-oil cooler and an
alternate air path to recycle cabin air through the air-oil cooler?
--------------------------------------------
On Wed, 1/4/17, William Hunter <billhuntersemail@gmail.com> wrote:
Subject: RE: AeroElectric-List: EMI From Seat Heaters and Other Questions
To: aeroelectric-list@matronics.com
Date: Wednesday, January 4, 2017, 3:31 PM
#yiv3929019256
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#yiv3929019256 Thanks All for your time in
contributing to this subject. I certainly came to the
right place. DANGand I thought that a
BTU was a form of currency changing because I see BTU
on my utility bill and my currency changes from my account
to the utility company account...
Cheers!!!
Bill Hunter
From:
owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On
Behalf Of Alec Myers
Sent:
Wednesday, January 4, 2017 4:31 AM
To: aeroelectric-list@matronics.com
Subject: Re: AeroElectric-List: EMI From
Seat Heaters and Other Questions Someone has their units mixed
up here. BTU is a measure of energy. Heaters are measured in
BTU/hour. (Like the difference between joules and watts).
480W is 1638BTU/h, and 8000BTU/h is 2344W so the two figures
given don't seem to agree. The former seems more
reasonable than the latter for this unit.
On Jan 3,
2017, at 23:50, Eric Page <edpav8r@yahoo.com>
wrote:On Jan 3, 2017, at 6:20 PM,
William Hunter <billhuntersemail@gmail.com>
wrote:QUESTION 4: How much heat would
a small 12 VDC
electric element heater
system realistically put out? This is
the one we have been discussing it is designed for a RV
unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm At the risk of being
pedantic, I'm not sure how one would answer this other
than to quote the product's specifications and explain
the units.
The
description says this heater rated for 8,016 British Thermal
Units (BTUs). A BTU is the amount of energy it takes to
heat one pound of water (about 16 fl oz, or two cups) by one
degree Fahrenheit. So, the heat energy this
thing puts out could heat a 4-ton tank of water (approx 960
US gal) by one deg F in one hour. Or, to use numbers that
are a bit more meaningful, heat about 96 gal of water by 10
deg F in one hour. Still not a very helpful
comparison.
The specs
say it draws 480W (40A at 12V). It looks like the blower
motor accounts for 15W (1.25A) of that total, which leaves
465W (38.75A) for the heating elements. That's a
decent amount of heat, but compare that figure against a
typical small domestic space heater that we're all
familiar with: they're commonly rated at 1,500W. The
first three search results for "hair dryer" on
Amazon are rated at 1,875W! Recommendations vary between
20 and 60 BTU/sq ft for heating a home, depending on your
climate region. If you assume a middle value of 40 BTU/sq
ft, then 8,000 BTU would be about right for a 200 sq ft room
(in a home insulated to code). Whether that kind of analysis
translates to airplanes, or if 8,000 BTU is adequate for a
light plane cockpit flying through freezing air are
interesting questions. How warm is warm
enough?
Eric
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