Today's Message Index:
----------------------
1. 10:14 AM - Reversible Spal Cooling Fans (William Hunter)
2. 12:00 PM - Re: Reversible Spal Cooling Fans (Robert L. Nuckolls, III)
3. 12:25 PM - Re: Reversible Spal Cooling Fans (don van santen)
4. 12:58 PM - Re: Reversible Spal Cooling Fans (Henry Hallam)
5. 02:50 PM - Re: Reversible Spal Cooling Fans (William Hunter)
6. 04:43 PM - Re: Reversible Spal Cooling Fans (Eric Page)
7. 04:50 PM - Re: Reversible Spal Cooling Fans (Eric Page)
8. 10:55 PM - Re: Reversible Spal Cooling Fans (Henry Hallam)
Message 1
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Subject: | Reversible Spal Cooling Fans |
I have a Velocity (pusher) that has the original design with two NACA
scoops in the roof of the airplane and this provides good cooling in flight
however on the ground and at low altitudes it is a bit lacking during times
with hot OAT (where I fly).
Since I recently retrofitted a turbocharger intercooler I also installed a
third cooling air scoop and dual 10 inch Spal automobile cooling fans that
blast 650 CFM each and these fans will both cool the intake air charge and
they will also add supplemental cooling to the engine when energized.
So will this new design I will have solved my hot OAT ground/low altitude
cooling issue however I am concerned that during really cold operations it
might be too much engine cooling.
Is it possible to reverse the fans and the airflow so when it is really
cold outside the fans will prevent the third cooling duct from providing
too much cooling air to the engine?
The fans have a on/off switch that utelize a relay (on relay for each fan)
to complete the circuit to electrify the fans... in other words each fan
has a heavy gauge wire with an inline fuse for protection and there is a
cockpit panel CB protected "accessory feed" (sorry... automotive term.)
that provides power through the ON/OFF switch to the automotive relay and
when the switch is ON the accessory feed completes the circuit and the
relay closes its contacts and the circuit for the heavy gauge wire is
completed and the fans run.
So is it possible to design a system that can reverse the fans?
This system would have to utilize four relays (two for each fan) that would
change both the 12 VDC power feed and the ground for each fan.
I imagine that there is a duplex relay box out there in the world for such
a need.
Does anyone know of such a design /contraption?
THANKS!!!
Bill Hunter
Message 2
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Subject: | Re: Reversible Spal Cooling Fans |
At 12:11 PM 3/12/2017, you wrote:
>I have a Velocity (pusher) that has the original
>design with two NACA scoops in the roof of the
>airplane and this provides good cooling in
>flight however on the ground and at low
>altitudes it is a bit lacking during times with hot OAT (where I fly).=C2
>
>Since I recently retrofitted a turbocharger
>intercooler I also installed a third cooling air
>scoop and dual 10 inch Spal automobile cooling
>fans that blast 650 CFM each and these fans will
>both cool the intake air charge and they will
>also add supplemental cooling to the engine when energized. =C2
>
>So will this new design I will have solved my
>hot OAT ground/low altitude =C2 cooling issue
>however I am concerned that during really cold
>operations it might be too much engine cooling.=C2
>
>Is it possible to reverse the fans and the
>airflow so when it is really cold outside the
>fans will prevent the third cooling duct from
>providing too much cooling air to the engine?=C2
Need more info. Are these permanent magnet
motor driven fans? I.e. TWO wires coming
out that can be driven either polarity.
One connection produces CCW rotation, reversed
connection produces CW rotation.
>The fans have a on/off switch that utelize a
>relay (on relay for each fan) =C2 to complete the
>circuit to electrify the fans... in other words
>each fan has a heavy gauge wire with an inline
>fuse for protection and there is a cockpit panel
>CB protected "accessory feed" (sorry...
>automotive term.) that provides power through
>the ON/OFF switch to the automotive relay and
>when the switch is ON the accessory feed
>completes the circuit and the relay closes its =C2
>contacts and the circuit for the heavy gauge
>wire is completed and the fans run.=C2
These sound like modern, automotive fans
that are most likely brushless motors. To reverse
rotation, you need access to the inner workings
of the electronics . . . generally hard if not
totally impractical.
Can you give us a link to the description of the
products? how much current do they draw?
Bob . . .
Message 3
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Subject: | Re: Reversible Spal Cooling Fans |
Instead of reversing the fans I would try reducing the exit size where the
cooling ait leaves the cowl. This could be as simple as tapeing over part
ot the exit.
Another way to keep the engine warm during cold conditions that is commonly
done to RV av is to cover up to one half ot the oil cooler inlet with a
removable plate.
On Mar 12, 2017 12:13, "Robert L. Nuckolls, III" <
nuckolls.bob@aeroelectric.com> wrote:
At 12:11 PM 3/12/2017, you wrote:
I have a Velocity (pusher) that has the original design with two NACA
scoops in the roof of the airplane and this provides good cooling in flight
however on the ground and at low altitudes it is a bit lacking during times
with hot OAT (where I fly).=C3=82
Since I recently retrofitted a turbocharger intercooler I also installed a
third cooling air scoop and dual 10 inch Spal automobile cooling fans that
blast 650 CFM each and these fans will both cool the intake air charge and
they will also add supplemental cooling to the engine when energized. =C3
=82
So will this new design I will have solved my hot OAT ground/low altitude
=C3=82
cooling issue however I am concerned that during really cold operations it
might be too much engine cooling.=C3=82
Is it possible to reverse the fans and the airflow so when it is really
cold outside the fans will prevent the third cooling duct from providing
too much cooling air to the engine?=C3=82
Need more info. Are these permanent magnet
motor driven fans? I.e. TWO wires coming
out that can be driven either polarity.
One connection produces CCW rotation, reversed
connection produces CW rotation.
The fans have a on/off switch that utelize a relay (on relay for each fan)
=C3=82 to complete the circuit to electrify the fans... in other words each
fan
has a heavy gauge wire with an inline fuse for protection and there is a
cockpit panel CB protected "accessory feed" (sorry... automotive term.)
that provides power through the ON/OFF switch to the automotive relay and
when the switch is ON the accessory feed completes the circuit and the
relay closes its =C3=82 contacts and the circuit for the heavy gauge wire i
s
completed and the fans run.=C3=82
These sound like modern, automotive fans
that are most likely brushless motors. To reverse
rotation, you need access to the inner workings
of the electronics . . . generally hard if not
totally impractical.
Can you give us a link to the description of the
products? how much current do they draw?
Bob . . .
Message 4
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Subject: | Re: Reversible Spal Cooling Fans |
My guess is that if you can just turn the fans off, that'll be
sufficient to prevent any "over-cooling". Can you be a bit more
specific about which scenarios you're concerned about? Perhaps on the
ground in cold weather taking too long for the oil and cylinders to
warm up before takeoff?
Henry
On Sun, Mar 12, 2017 at 12:21 PM, don van santen <donvansanten@gmail.com> wrote:
> Instead of reversing the fans I would try reducing the exit size where the
> cooling ait leaves the cowl. This could be as simple as tapeing over part ot
> the exit.
> Another way to keep the engine warm during cold conditions that is commonly
> done to RV av is to cover up to one half ot the oil cooler inlet with a
> removable plate.
>
> On Mar 12, 2017 12:13, "Robert L. Nuckolls, III"
> <nuckolls.bob@aeroelectric.com> wrote:
>
> At 12:11 PM 3/12/2017, you wrote:
>
> I have a Velocity (pusher) that has the original design with two NACA scoops
> in the roof of the airplane and this provides good cooling in flight however
> on the ground and at low altitudes it is a bit lacking during times with hot
> OAT (where I fly).
>
> Since I recently retrofitted a turbocharger intercooler I also installed a
> third cooling air scoop and dual 10 inch Spal automobile cooling fans that
> blast 650 CFM each and these fans will both cool the intake air charge and
> they will also add supplemental cooling to the engine when energized.
>
> So will this new design I will have solved my hot OAT ground/low altitude
> cooling issue however I am concerned that during really cold operations it
> might be too much engine cooling.
>
> Is it possible to reverse the fans and the airflow so when it is really cold
> outside the fans will prevent the third cooling duct from providing too much
> cooling air to the engine?
>
>
> Need more info. Are these permanent magnet
> motor driven fans? I.e. TWO wires coming
> out that can be driven either polarity.
>
> One connection produces CCW rotation, reversed
> connection produces CW rotation.
>
>
> The fans have a on/off switch that utelize a relay (on relay for each fan)
> to complete the circuit to electrify the fans... in other words each fan has
> a heavy gauge wire with an inline fuse for protection and there is a cockpit
> panel CB protected "accessory feed" (sorry... automotive term.) that
> provides power through the ON/OFF switch to the automotive relay and when
> the switch is ON the accessory feed completes the circuit and the relay
> closes its contacts and the circuit for the heavy gauge wire is completed
> and the fans run.
>
>
> These sound like modern, automotive fans
> that are most likely brushless motors. To reverse
> rotation, you need access to the inner workings
> of the electronics . . . generally hard if not
> totally impractical.
>
> Can you give us a link to the description of the
> products? how much current do they draw?
>
> Bob . . .
>
>
Message 5
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Subject: | Reversible Spal Cooling Fans |
Bob and Henry,
Thank you for your willingness to help.
> Need more info. Are these permanent magnet motor driven fans? I.e.
TWO wires coming
out that can be driven either polarity. ...These sound like modern,
automotive fans
that are most likely brushless motors. To reverse rotation, you need
access to the inner workings of the electronics . . . generally hard
if not totally impractical.
The aftermarket automotive fans are electrically insulated and are
designed to be reversible and mounted on a plastic shroud and they have
a red and a black wire coming out of the back. I bench tested the fans
and they turn backwards when the polarity is reversed.
https://www.amazon.com/gp/product/B004LY3Z9Y/ref=oh_aui_search_detailpa
ge?ie=UTF8&psc=1
I have attached a PDF document of the wire diagram. If the AeroElectric
server does not allow for attachments then this image link might work:
https://cimg2.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/730x780/80-s
pal_wiring_diagram_78eade2fe4e5395ef98534dbc5f50f97483be5ee.jpg
I am using the bottom dual fan design however this wire diagram shows
the ground wire of the relay to be connected to a Normally Open
temperature actuated switch that is installed in the lower radiator of a
car installation with the intent that when the radiator coolant gets
above a certain temperature the thermos-switch will close and the relay
coil wire will be grounded and the relay contacts close and the 12VDC
power will flow to the fan motors. My relay coil wire will always be
grounded and therefore the 12VDC "accessory" feed will be switched on or
off to energize the relay coil.
During hot weather ground operations and low indicated airspeed, the
Velocity with the propeller in the back has very little engine cooling
airflow and some airplanes have engine overheating concerns during long
taxi and initial climb.
During cold weather operations, the Velocity with the Lycoming only has
one oil cooler and this is located in the nose compartment. Outside ram
air is pushed through this oil cooler and either ducted outboard or when
the pilot needs heat inside the cabin, the outlet of the oil cooler is
ducted into the cabin and used for heat. Some Velocity builders report
poor cabin heating from this system in very cold OAT because they have
trouble keeping their engine warmed up enough to allow the oil to be to
be diverted to the oil cooler up front.
With these two fans and new intake scoop I will certainly have solved
the ground/low IAS cooling problem however with this new 1 inch by 14
inch additional engine cooling air intake scoop, I will have amplified
this cold OAT problem.
If the fans can be reversed then during cold weather operations, they
will blow backwards and stall out the ram air coming down this new scoop
with the only weight penalty being a couple of extra relays and some
wiring.
THANKS AGAIN!!!
..
Cheers!!!
Bill Hunter
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Henry
Hallam
Sent: Sunday, March 12, 2017 12:55 PM
Subject: Re: AeroElectric-List: Reversible Spal Cooling Fans
--> <henry@pericynthion.org>
My guess is that if you can just turn the fans off, that'll be
sufficient to prevent any "over-cooling". Can you be a bit more
specific about which scenarios you're concerned about? Perhaps on the
ground in cold weather taking too long for the oil and cylinders to warm
up before takeoff?
Henry
On Sun, Mar 12, 2017 at 12:21 PM, don van santen
<donvansanten@gmail.com> wrote:
> Instead of reversing the fans I would try reducing the exit size where
> the cooling ait leaves the cowl. This could be as simple as tapeing
> over part ot the exit.
> Another way to keep the engine warm during cold conditions that is
> commonly done to RV av is to cover up to one half ot the oil cooler
> inlet with a removable plate.
>
> On Mar 12, 2017 12:13, "Robert L. Nuckolls, III"
> <nuckolls.bob@aeroelectric.com> wrote:
>
> At 12:11 PM 3/12/2017, you wrote:
>
> I have a Velocity (pusher) that has the original design with two NACA
> scoops in the roof of the airplane and this provides good cooling in
> flight however on the ground and at low altitudes it is a bit lacking
> during times with hot OAT (where I fly).=C3=82
>
> Since I recently retrofitted a turbocharger intercooler I also
> installed a third cooling air scoop and dual 10 inch Spal automobile
> cooling fans that blast 650 CFM each and these fans will both cool the
> intake air charge and they will also add supplemental cooling to the
> engine when energized. =C3=82
>
> So will this new design I will have solved my hot OAT ground/low
> altitude =C3=82 cooling issue however I am concerned that during
really
> cold operations it might be too much engine cooling.=C3=82
>
> Is it possible to reverse the fans and the airflow so when it is
> really cold outside the fans will prevent the third cooling duct from
> providing too much cooling air to the engine?=C3=82
>
>
> Need more info. Are these permanent magnet
> motor driven fans? I.e. TWO wires coming
> out that can be driven either polarity.
>
> One connection produces CCW rotation, reversed
> connection produces CW rotation.
>
>
> The fans have a on/off switch that utelize a relay (on relay for each
> fan) =C3=82 to complete the circuit to electrify the fans... in other
words
> each fan has a heavy gauge wire with an inline fuse for protection and
> there is a cockpit panel CB protected "accessory feed" (sorry...
> automotive term.) that provides power through the ON/OFF switch to the
> automotive relay and when the switch is ON the accessory feed
> completes the circuit and the relay closes its =C3=82 contacts and the
> circuit for the heavy gauge wire is completed and the fans run.=C3=82
>
>
> These sound like modern, automotive fans
> that are most likely brushless motors. To reverse
> rotation, you need access to the inner workings
> of the electronics . . . generally hard if not
> totally impractical.
>
> Can you give us a link to the description of the
> products? how much current do they draw?
>
> Bob . . .
>
>
Message 6
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Subject: | Re: Reversible Spal Cooling Fans |
billhuntersemail(at)gmail wrote:
> The aftermarket automotive fans are electrically insulated and are designed to
be reversible and mounted on a plastic shroud and they have a red and a black
wire coming out of the back. I bench tested the fans and they turn backwards
when the polarity is reversed.
>
> https://www.amazon.com/gp/product/B004LY3Z9Y/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Quoting from the Amazon listing: "Blades and polarity of the wiring can be reversed
and it becomes a pusher fan."
I take this to mean that you must reverse *both* the polarity of the power supply
*and* the mounting of the blade rotor on its shaft to make the fan operate
in reverse. Those blades don't look like they'll move air very well if you simply
rotate them in the reverse direction; they appear very much optimized for
their direction of rotation.
Do the fans' instructions say anything about installing them for reverse operation?
Eric
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=467217#467217
Message 7
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Subject: | Re: Reversible Spal Cooling Fans |
Quoting again from Amazon, this time from one of the reviews of these fans: "I
changed these from "pullers" to "pushers" by flipping the blades and wiring it
opposite of the instructions..."
Eric
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=467218#467218
Message 8
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Subject: | Re: Reversible Spal Cooling Fans |
Hi Bill,
Good job testing that they work in reverse on the bench. It might be
worth measuring how much current they draw at 14.4V - the Amazon page
suggests 25A, which is a hefty pair of fans, and a potentially a
significant chunk of your alternator's capacity!
Instead of the relays in your diagram, one option is to just use a
high-current On-Off-On 3-position DPDT switch such as one of these:
http://www.digikey.com/short/325mhp
Referring to the schematic symbol for the DPDT on page 2 of this
datasheet: http://www.nkkswitches.com/pdf/stoggleshighcap.pdf ,
2 = Protected (fuse or CB) +14V
5 = Ground
1 = 6 = Motor red
3 = 4 = Motor black
You can see it graphically here: https://www.eleinmec.com/figures/012_02.gif
If you want to keep the wires in the panel skinny (might be desirable
for a pusher), you can achieve a similar effect with a DPDT relay (to
swap between forward and reverse), an SPST relay (to switch off and
on), with the coils enabled by either two separate SPST switches or a
single SPDT On-Off-On switch with a diode to let the second "On"
position power both relays. Let me know if you need a diagram :)
Regardless of whether you use a high-current switch or relays, you
should also place a suitable bidirectional TVS diode across the motor
terminals to help suppress arcs in the switch/relay contacts:
http://www.digikey.com/product-detail/en/littelfuse-inc/TP5KP15CA/F7654CT-ND/6174274
Good luck,
Henry
On Sun, Mar 12, 2017 at 2:46 PM, William Hunter
<billhuntersemail@gmail.com> wrote:
> Bob and Henry,
>
> Thank you for your willingness to help.
>
>> Need more info. Are these permanent magnet motor driven fans? I.e. TWO wires
coming
> out that can be driven either polarity. ...These sound like modern, automotive
fans
> that are most likely brushless motors. To reverse rotation, you need access
to the inner workings of the electronics . . . generally hard if not totally
impractical.
>
> The aftermarket automotive fans are electrically insulated and are designed to
be reversible and mounted on a plastic shroud and they have a red and a black
wire coming out of the back. I bench tested the fans and they turn backwards
when the polarity is reversed.
>
> https://www.amazon.com/gp/product/B004LY3Z9Y/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
>
> I have attached a PDF document of the wire diagram. If the AeroElectric server
does not allow for attachments then this image link might work:
>
> https://cimg2.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/730x780/80-spal_wiring_diagram_78eade2fe4e5395ef98534dbc5f50f97483be5ee.jpg
>
>
> I am using the bottom dual fan design however this wire diagram shows the ground
wire of the relay to be connected to a Normally Open temperature actuated
switch that is installed in the lower radiator of a car installation with the
intent that when the radiator coolant gets above a certain temperature the thermos-switch
will close and the relay coil wire will be grounded and the relay
contacts close and the 12VDC power will flow to the fan motors. My relay coil
wire will always be grounded and therefore the 12VDC "accessory" feed will be
switched on or off to energize the relay coil.
>
> During hot weather ground operations and low indicated airspeed, the Velocity
with the propeller in the back has very little engine cooling airflow and some
airplanes have engine overheating concerns during long taxi and initial climb.
>
> During cold weather operations, the Velocity with the Lycoming only has one oil
cooler and this is located in the nose compartment. Outside ram air is pushed
through this oil cooler and either ducted outboard or when the pilot needs
heat inside the cabin, the outlet of the oil cooler is ducted into the cabin
and used for heat. Some Velocity builders report poor cabin heating from this
system in very cold OAT because they have trouble keeping their engine warmed
up enough to allow the oil to be to be diverted to the oil cooler up front.
>
> With these two fans and new intake scoop I will certainly have solved the ground/low
IAS cooling problem however with this new 1 inch by 14 inch additional
engine cooling air intake scoop, I will have amplified this cold OAT problem.
>
> If the fans can be reversed then during cold weather operations, they will blow
backwards and stall out the ram air coming down this new scoop with the only
weight penalty being a couple of extra relays and some wiring.
>
> THANKS AGAIN!!!
> ..
>
> Cheers!!!
>
> Bill Hunter
>
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Henry Hallam
> Sent: Sunday, March 12, 2017 12:55 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Reversible Spal Cooling Fans
>
> --> <henry@pericynthion.org>
>
> My guess is that if you can just turn the fans off, that'll be sufficient to
prevent any "over-cooling". Can you be a bit more specific about which scenarios
you're concerned about? Perhaps on the ground in cold weather taking too
long for the oil and cylinders to warm up before takeoff?
>
> Henry
>
> On Sun, Mar 12, 2017 at 12:21 PM, don van santen <donvansanten@gmail.com> wrote:
>> Instead of reversing the fans I would try reducing the exit size where
>> the cooling ait leaves the cowl. This could be as simple as tapeing
>> over part ot the exit.
>> Another way to keep the engine warm during cold conditions that is
>> commonly done to RV av is to cover up to one half ot the oil cooler
>> inlet with a removable plate.
>>
>> On Mar 12, 2017 12:13, "Robert L. Nuckolls, III"
>> <nuckolls.bob@aeroelectric.com> wrote:
>>
>> At 12:11 PM 3/12/2017, you wrote:
>>
>> I have a Velocity (pusher) that has the original design with two NACA
>> scoops in the roof of the airplane and this provides good cooling in
>> flight however on the ground and at low altitudes it is a bit lacking
>> during times with hot OAT (where I fly).
>>
>> Since I recently retrofitted a turbocharger intercooler I also
>> installed a third cooling air scoop and dual 10 inch Spal automobile
>> cooling fans that blast 650 CFM each and these fans will both cool the
>> intake air charge and they will also add supplemental cooling to the
>> engine when energized.
>>
>> So will this new design I will have solved my hot OAT ground/low
>> altitude cooling issue however I am concerned that during really
>> cold operations it might be too much engine cooling.
>>
>> Is it possible to reverse the fans and the airflow so when it is
>> really cold outside the fans will prevent the third cooling duct from
>> providing too much cooling air to the engine?
>>
>>
>> Need more info. Are these permanent magnet
>> motor driven fans? I.e. TWO wires coming
>> out that can be driven either polarity.
>>
>> One connection produces CCW rotation, reversed
>> connection produces CW rotation.
>>
>>
>> The fans have a on/off switch that utelize a relay (on relay for each
>> fan) to complete the circuit to electrify the fans... in other words
>> each fan has a heavy gauge wire with an inline fuse for protection and
>> there is a cockpit panel CB protected "accessory feed" (sorry...
>> automotive term.) that provides power through the ON/OFF switch to the
>> automotive relay and when the switch is ON the accessory feed
>> completes the circuit and the relay closes its contacts and the
>> circuit for the heavy gauge wire is completed and the fans run.
>>
>>
>> These sound like modern, automotive fans
>> that are most likely brushless motors. To reverse
>> rotation, you need access to the inner workings
>> of the electronics . . . generally hard if not
>> totally impractical.
>>
>> Can you give us a link to the description of the
>> products? how much current do they draw?
>>
>> Bob . . .
>>
>>
>
>
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