---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 03/12/17: 8 ---------------------------------------------------------- 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 _____________________________________ Time: 10:14:45 AM PST US From: William Hunter Subject: AeroElectric-List: 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 _____________________________________ Time: 12:00:18 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 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 _____________________________________ Time: 12:25:20 PM PST US From: don van santen Subject: Re: AeroElectric-List: 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 _____________________________________ Time: 12:58:05 PM PST US From: Henry Hallam Subject: Re: AeroElectric-List: 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 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" > 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 _____________________________________ Time: 02:50:28 PM PST US From: "William Hunter" Subject: RE: AeroElectric-List: 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 --> 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 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" > 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 _____________________________________ Time: 04:43:28 PM PST US Subject: AeroElectric-List: Re: Reversible Spal Cooling Fans From: "Eric Page" 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 _____________________________________ Time: 04:50:31 PM PST US Subject: AeroElectric-List: Re: Reversible Spal Cooling Fans From: "Eric Page" 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 _____________________________________ Time: 10:55:37 PM PST US From: Henry Hallam Subject: Re: AeroElectric-List: 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 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 > > --> > > 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 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" >> 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 . . . >> >> > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.