Aparently the motor is what is called 'brushless' with three wires - those types of motors are almost universally used by model aircraft enthusiasts.
Anyway, I ignored the yellow wire and connected the red and black to positive and negative but it fails to run the fan.
Applying the multimeter to everywhere shows that 12-Volts are going where it is supposed to, even into the fan leads.
So, is it possible to run a three wire electric motor on just two wires?
As I have cut the wires on the fan and soldered a two pin plug onto it I am unable to return it to Jaycar. If there is no way of making it run on two wires it looks like I;ll have to buy another fan - say Jaycar's Y2522.
I am heading to Geelong on Saturday and was hoping to have the installation finished before then. By the way, Geelong are forecast to have a maximum of 40-degrees on Friday - that would be a good test for how well the fan works. Luckily, the temperatures are supposed to drop to the high twenties for the next week.
Murray
Cadpete said
05:43 PM Dec 30, 2015
Hi Murray,
If it is a true 3 wire brushless motor the only way it can be run is with a motor controller, as it needs to have the power alternated between all three wires - see article here https://en.wikipedia.org/wiki/Brushless_DC_electric_motor
It cannot run from only two wires.
Pete
Long Weekend said
05:54 PM Dec 30, 2015
Hi CADPete,
Thanks. I was pretty sure that was the case.
When I get down south it looks like I'll have to buy another fan. YX2522 looks to be most suitable as it is supposed to run in a dusty environment. Providing that it only has two leads - Jaycar's catalog doesn't state how many wires.
Murray
dorian said
06:06 PM Dec 30, 2015
The third wire is used for PWM speed control. I would have thought that leaving it open would allow the fan to run at maximum speed, but maybe not. What voltage do you measure between the yellow and black leads?
BTW, you might be disappointed to find that the Manufacturer's Suggested Retail Price is only 12USD whereas Jaycar stung you for AU35.
Edit: The manufacturer's page is confusing. Apparently speed control is achieved by regulating the supply voltage with a supplied (?) voltage regulator.
The RPM speed of any fan can be controlled from full speed to low speed manually according to desire using this voltage regulator. This product is suitable for all high RPM fans and regulates between 5 and 12V.
Therefore the third wire must be the tacho output but I don't see any mention of it.
Here is the standard PC pinout for 3-wire and 4-wire fans:
-- Edited by dorian on Wednesday 30th of December 2015 06:33:01 PM
Long Weekend said
08:35 PM Dec 30, 2015
Thanks Dorian for the information links.
Not sure if it is possible to buy the Gelid type fans from overseas - world wide delivery is from China but Australia is not mentioned.
Anyway, I might check out one of the local Computer Fairs to see what fans they have. Overwise I'll have to go with another Jaycar one.
BTW, this has shown that the wiring circuit given by 'dreampod' will not operate fan YX2584. I wonder how many others have been caught out.
Murray
dorian said
09:15 PM Dec 30, 2015
The Wing12 model Gelid fan is the same as the one in the Jaycar photo. That's the only reason I brought it up. I was hoping that Gelid's web site would be able to provide useful information about their own products, but I was wrong. It does seem like you bought a dud, but it could be that the wiring colour codes are mixed up. Do you still have the end of the cable with the connector intact? The order of the wires should be as in the allpinouts.org page.
Long Weekend said
09:15 PM Dec 30, 2015
I just retrieved the packet that fan YX2584 came in - there was no mention of a speed control being required on it, nor were any instructions provided. Apparently speed controls are already integrated in the computer.
Also, checking Jaycar's catalog with a magnifying glass reveals that all the 120mm fans, except one 12-Volt one are brushless - ie, they all require a speed control. The exception is YX2518 which although specified as being 12VDC with two wires the writing on the motor hub states that it operates on 240-Volts!
YX2522 that I thought may be suitable also turns out to be brushless.
How have other people managed to fit 120mm fans in their vans?
Another thought was to parallel several small fans but most of them in Jaycar's catalog are also brushless. Some of the others have only sleeve bearings rather than ball so only have a finite life and probable more noisy.
Anyway, I will have a look around Geelong while we are down there - and hope that we don't have a number of 40-degree days to test the refrigerator out.
Murray
-- Edited by Long Weekend on Wednesday 30th of December 2015 09:44:04 PM
Long Weekend said
09:54 PM Dec 30, 2015
Hi Dorian - we double posted at the same time.
Yes, I still have the plug and attached cable. There are no pin numbers on the plug, red is center with black and yellow on each side. It is polarised by two raised ridges on each side to fit into grooves in the socket. As mentioned I cut the plug off and run the red and black through a two pin polarised plug and socket - the locking type so that vibration won't separate them.
I checked eBay - most of the fans on them are also brushless, that is, require three wires. The two wire ones all seem to be sleeve bearings.
The only thing I haven't tried is to connect the fan direct to the 12-Volt supply rather than through the harness I made up.
I wonder how come others seem to have installed fans in their fridge enclosure without any problems?
Murray
-- Edited by Long Weekend on Wednesday 30th of December 2015 09:58:11 PM
madaboutled said
11:55 PM Dec 30, 2015
Long Weekend wrote:
Hi Dorian - we double posted at the same time.
Yes, I still have the plug and attached cable. There are no pin numbers on the plug, red is center with black and yellow on each side. It is polarised by two raised ridges on each side to fit into grooves in the socket. As mentioned I cut the plug off and run the red and black through a two pin polarised plug and socket - the locking type so that vibration won't separate them.
I checked eBay - most of the fans on them are also brushless, that is, require three wires. The two wire ones all seem to be sleeve bearings.
The only thing I haven't tried is to connect the fan direct to the 12-Volt supply rather than through the harness I made up.
I wonder how come others seem to have installed fans in their fridge enclosure without any problems?
Murray
-- Edited by Long Weekend on Wednesday 30th of December 2015 09:58:11 PM
The three wire brushless motors are essentially a 3 phase motor that needs to be run through an electronic controller which will controll direction and speed. The brushless fans others have used are 2 phase motors that can be run without a controller, many of these are computer fans.
This article may help with the technical aspects: https://en.wikipedia.org/wiki/Brushless_DC_electric_motor
edit typo
-- Edited by madaboutled on Wednesday 30th of December 2015 11:56:28 PM
Cadpete said
12:00 AM Dec 31, 2015
Hi Murray,
Is there an Altronics nearer to you? They have a mag-lev 120mm fan for $25.95 which is definately 12vDC, even has original documentation link.
I used silicone sealant to glue the case fans to the external vent with a small recessed easily accessible kill switch hidden in the vents.
Using a cheap InfraRed Thermometer from SuperCheap Auto AUD$27 I measured the temperatures of the pipes leading into and out of the radiator part of the fridge.
Having chosen a suitable location on the pipe work I then measured the outside diameter of the pipe with my cheapo vernier calipers and ordered the appropriate temp and diameter thermo switch from Senasys.
Wiring was simple enough connecting to the existing terminal strip that has the 12 volt power to the fridge, via a fuse, then the kill switch, then the thermo switch, then the fans.
Less than $50 (I already had the tools) and it works super well. When the temperature gets hot the fans turn on. They are super quiet whilst sucking out the hot air from the radiator area. Previously the fidge simply couldn't cope with temps over 30C now it works perfectly even on 40C+ days.
PS. I tried the Jaycar type thermo switches and they simply don't work. They are flat and don't have the proper surface contact with the pipework. Any attempt to strap the flat type to a pipe using something like a hose clamp results in the clamp acting as a heatsink which draws away heat from the switch so it doesn't work. Those flat type are also very delicate and the flat face can be deformed easily which destroys them.
-- Edited by Hylife on Thursday 31st of December 2015 12:59:15 AM
-- Edited by Hylife on Thursday 31st of December 2015 01:06:37 AM
All computer fans in use today appear to be brushless. That goes for 2-wire, 3-wire and 4-wire fans. The difference is that the 3-wire fans provide a tacho output on the 3rd wire, and 4-wire fans provide a PWM based speed control input on the 4th wire. All have built-in electronic commutation.
The Gelid documentation is crap, but it appears that it is a typical 3-wire computer fan with a tacho output, so it should run with only two wires. The manufacturer supplies an additional electronic voltage regulator to vary the supply voltage (all for US$12 MSRP), presumably from 5V to 12V. 5V is the minimum start voltage and is probably the supply voltage for its internal commutation IC. It appears that Jaycar gouges its customers by doubling the MSRP and deleting the voltage regulator.
In short, the YX2584 fan should work with only two wires.
The listing states that you can connect your 3-pin fan cable to a standard 4-pin PSU Molex connector, ie only the +12V and Ground wires are required.
-- Edited by dorian on Thursday 31st of December 2015 06:11:38 AM
Long Weekend said
09:49 AM Dec 31, 2015
Thanks for all the replies.
CADPete
We do not have an Altronics outlet here in Canberra. But looking at Altronics web site there is an outlet in Geelong - actually within walking distance across the river from the caravan park where we are staying. Parking in that particular street is pretty tight so I will take a stroll over the bridge.
Thanks for the info.
HYLIFE
Very impressive setup. May I ask why three fans? Others seem to get by with only the one.
Also I see each fan has three wires. Are they powered by some sort of controller?
I take your point about the thermostat. The Jaycar one slithered everywhere while I was strapping it onto the pipe. I did wonder about the flat base going onto the rounded pipe but then figured if Dreampod had used one it must be alright. Nonetheless, I'll consider buying one of the Sensys ones, probably the same one as in your photo.
DORIAN
I have added the Gelid fan onto my watch list on eBay. When we return from Geelong I'll look into it further. I did notice that a controller is not included with that particular fan so I might have to chase it up separately.
Also, some further experimenting may get the YX2584 to work.
ANYWAY
We will be on the road on Saturday, two nights in Seymour then 14 days in Geelong. So it looks like everything will be on hold until our return in the second half of January. Pity, because Geelong always has several days over 40-degrees during January but I guess for this (next) year we will just have to make the best of it. But I imagine that there will still be more hot days ahead in January and February to make the fans worthwhile.
Murray
Long Weekend said
11:16 AM Dec 31, 2015
Cadpete wrote:
Hi Murray,
Is there an Altronics nearer to you? They have a mag-lev 120mm fan for $25.95 which is definately 12vDC, even has original documentation link.
Whoops! Just had a look at the Altronics link for the fan. While it does have two wires it is a 240-Volt fan!
Actually, the heading does state it is 12-Volt but the specifications on the motor hub states 240-Volts. I'll have to physically check one to see what is correct.
So back to the drawing board.
People have been putting 12-Volt fans in their fridge cabinets for years now, so why am I having trouble with my set up?
Murray
-- Edited by Long Weekend on Thursday 31st of December 2015 11:20:18 AM
mr glassies said
03:54 PM Dec 31, 2015
hmmm i think i have a 3 wire fan works of a small solar panel . have 3 on the bottom vent on the van . my idea is the air of the fans blow straight onto the compressor . if i put it on the top vent the air would miss the compressor as the vents are about 40 degree angel pushing the air away from were intended to go. i also have a 50 mll fan inside the fridge to push the air around hopefully stopping cold or hot spots so to speak .
dibs
Cadpete said
05:01 PM Dec 31, 2015
Photo is generic Murray, Sunon part number does not match Sunon part number for 12V fan!. If in doubt double check with the store.
Hylife said
05:30 PM Dec 31, 2015
LongWeekend <quote> May I ask why three fans? Others seem to get by with only the one. </quote>
Whilst the absorption fridge process is simple enough, it is quite convoluted in its pipe works. Our needs relate to the beginning of the process where the ammonia and water mix is heated to an evaporation point and then immediately must be cooled slightly, relying on heat radiating away passively from the 'condenser' fins. This is why they don't work in high temp climates.
The more air you can draw over the condenser fins the faster the ammonia/water separation takes place further in the pipework and the better cooling from the ammonia.
You could always start with one fan and add more later. I bought the 120mm sized units because they are almost silent running with the bigger blades and rather than mounting them somewhere in the cavity space I chose to have them directly expel the cavity air to the outside environment.
LongWeekend <quote> Also I see each fan has three wires. Are they powered by some sort of controller? </quote>
As Dorian mentioned, computer fans with three wires provide RPM feedback to the motherboard which can be used for temperature Vs fan speed control. In my situation I only used the red and black wires and trimmed off the yellow ones. The controller is the thermo switch clamped to the pipework. Senasys have these switches available for different pipe sizes and temperature switch points, so on choosing where you will fit the switch (required space) measure the outside pipe diameter and the operating temperature at that point with your vernier caliper and IR thermometer and order what suits your fridge.
-- Edited by Hylife on Thursday 31st of December 2015 05:45:45 PM
PeterD said
05:47 PM Dec 31, 2015
If you go to the Jaycar cattledog you will see:
Black - earth Red - 12 V Yellow - tacho output (1 pulse/rev)
If you have not stuffed the electronic circuitry, just roll back the yellow and it should work.
-- Edited by PeterD on Thursday 31st of December 2015 05:48:47 PM
Long Weekend said
05:47 PM Dec 31, 2015
For Pete,
I'll be able to hold one of the fans in my hand sometime in the next week so will make sure that it is indeed two wire 12-Volt.
For Hylife,
I have checked out the thermostats from Senasys. It looks like the type 430 would be better than the type 431. The difference being the 431 has fly leads while the 430 has quick connector tabs like the Jayco thermostat.
I measured the pipe on our fridge and it was 22mm. Converting that to Imperial comes to close to 7/8th-inch and that will be the mounting bracket. Also converting 70-degrees Celsius to Fahreheit comes to 158-degrees F.
Murray
-- Edited by Long Weekend on Thursday 31st of December 2015 06:02:40 PM
Long Weekend said
06:09 PM Dec 31, 2015
Hi PeterD,
Yes, I saw that the yellow was the tacho and I ignored that. As far as I can be certain I had the polarity right - red positive and black negative on all my wiring and plugs.
Anyway, we are in the process of packing up ready to head off on Saturday so will leave everything until we return back home.
By the way, Geelong had 40-degrees today - just the weather to utilise a fan to help the fridge along.
Murray
Hylife said
06:45 PM Dec 31, 2015
LongWeekend, I chose the 12" flylead version because of the space constraints at the back of my 20 year old Jayco's fridge, and, it meant that I could keep the wiring tidy knowing that their OEM leads would not have degradation problems with the close proximity of the radiating heat.
The switches do come with the pipe clamp to match the outside diameter of your pipe, although I had to squeeze it's open ends together a bit. So long as you consider the fitment location and how you will route your wires it really is an easy upgrade job. I used ordinary spade connectors (crimped only), but with a short length of heatshrink tubing for protection from shorts and to prevent unwanted contamination or disconnects.
I'm in hoppers so yes it was hot today.
-- Edited by Hylife on Thursday 31st of December 2015 06:46:00 PM
Long Weekend said
08:18 PM Dec 31, 2015
Hi Hylife,
On a second look it seems that type 430 has a flat base while type 431 has a curved - at least that what it looks like in the picture.
How did you order yours from Senasy? When I tried to place an order I couldn't get past the country - it would only accept USA or Canada. When I typed Australia in the country box it simply went blank so I couldn't get any further. They accept PayPal so there was no problems with payment.
By the way, for anybody who wishes to order one of these thermostats the fly leads come in two lengths - 12-inches and a massive 72-inches. That's 6-feet in the old language!
At least tomorrow will be a bit cooler for you. We will be in Geelong for two weeks so expect that there will be another 40-degree day before we leave. One year it was 45-degrees on one day - the hottest in the state.
Murray
JeffRae said
09:41 PM Jan 3, 2016
"12-inches and a massive 72-inches. That's 6-feet in the old language!"
That's funny Long Weekend, all the measurements are in the old language
Have done this modification on our van using an old computer fan, it makes a difference
Hylife said
01:48 PM Jan 7, 2016
I too had that on-line ordering issue so I sent them and email and they replied back that their online store could only process local orders but that they were only too happy to supply overseas if I could give them with what info they needed.
EG: Part number, description, quantity, shipping address, credit card details.
I proceeded through the online system drop down choices, added them to the cart and then I took a screen copy of the cart and saved that as a picture file. http://www.senasys.com/shop/product/12-sealed-thermostat-switch-431-301a820f/ I then attached the picture file to my email order message so there could be no confusion as to exactly what I wanted to order.
They processed the order via PayPal. :) and I received the goods in approx a week and a half.
Remember, that unlike the rest of the world, postage costs in the USA (USPS) are very expensive, and for international freight most businesses want tracking, so will only use the Priority Mail service which is US$26.50. If you have some GN friends that might also be considering the same mod then it is worth combining an order to spread the freight costs. The box they came in could easily fit a dozen switches. The switches only cost US$11.75 each, but even with the added cost of freight it was still worth it because as I've said before, the flat surface thermal switches such as you can buy locally from Jaycar simply don't work properly on a round pipe and are far too delicate for our needs, and no one sells pipe-mount units in Oz.
For my 20 year old fridge in my Jayco I had the fridge running for an hour or two on a normal 25C day and using the InfraRed Thermometer measured the temps at different places along the pipework close to the condensor grills. At my chosen mounting locations the pipes are of two outside diameter sizes, 5/8" and 7/8". Unsure of which would be more sucessfull in switching on and off as required I ordered a 431 5/8" close at 125F and a 431 7/8" close at 150F.
I am currently using the 431 7/8" close at 150F and have it mounted on the pipe leading into the condensor grill as it comes up from the heating area. It seems to be the right choice for my setup.
CC Bear said
09:33 PM Jan 7, 2017
Hylife looking at your photo above I can understand the operation with the switch and fans. As your fans sit in the picture can you do a wiring diagram and post it please
When you run your fridge for the time to test the temperature what source did you use or does it not matter.
Were you looking for the general operating temperature and any thing higher the fans would cut in.
Did you pick up you 12 volt feed and negative as it came from your battery and could you use any 12 v source to provide power.
This is all new to me but willing to learn thank you.
-- Edited by CC Bear on Saturday 7th of January 2017 10:58:30 PM
Hylife said
09:31 PM Jan 8, 2017
There is already a 12V supply at the bottom rear of the fridge. Goes to a small terminal strip and then on to the 3 way switch at the front.
The 12V normally is of p!ssy little wires that are not big enough for the 20+ amps that 3ways draw.
I wired heavy duty 6mm direct to the vans house 100AH deep cycle (with a 30amp self resetting circuit breaker from Jaycar), that way there is always sufficient juice to the fridge when on 12V, even when stooped for lunch with the car not running (have a DC-DC charger for car to charge house batt whilst driving).
Tapped into the 12V at the small terminal strip in the back of the fridge. Positive goes to a fuse, to the thermo switch, then to the fans (all in parallel). Neg goes straight to fans neg.
Used a cheapo thermometer gun bought at SCA on a hot day to measure MY system pipes at various locations and ordered the switch based on that.
Your fridge will have different temps so order your switch 'turn on temp' specifically for your fridge, after you have measured your pipework at a few places whilst running on a suitably hot day.
CC Bear said
10:10 PM Jan 8, 2017
Thank you have the general idea, will get the thermogun in the next couple of days and check the temperatures over the rest of the week. Have ordered the fans so they should be here next week. Cheers
another question I take it when you ran the new wire from the van battery you disconnected the charge wire ( at the fridge ) coming from your tug plug.
-- Edited by CC Bear on Sunday 8th of January 2017 10:15:19 PM
CC Bear said
08:19 AM Jan 9, 2017
Throw in another here your 6mm wire is it 6 mm auto, 6 mm square or 6 B & S.
removed question answer in previous post thankd
-- Edited by CC Bear on Monday 9th of January 2017 08:32:54 AM
-- Edited by CC Bear on Monday 9th of January 2017 11:49:13 AM
CC Bear said
02:21 PM Jan 9, 2017
Went to Supercheap Auto today and the infared thermometers are now $69:90 big rise in 12 months.
(I originally posted this at the end of the thread started by OutbackMK on 6 December, but realised that nobody would see it three pages back!)
Something for electricians!
I bought all the components listed in the site www.dreampod.net/boroma/fridgefan.html but the fan does not work with the wiring as shown.
Aparently the motor is what is called 'brushless' with three wires - those types of motors are almost universally used by model aircraft enthusiasts.
Anyway, I ignored the yellow wire and connected the red and black to positive and negative but it fails to run the fan.
Applying the multimeter to everywhere shows that 12-Volts are going where it is supposed to, even into the fan leads.
So, is it possible to run a three wire electric motor on just two wires?
As I have cut the wires on the fan and soldered a two pin plug onto it I am unable to return it to Jaycar. If there is no way of making it run on two wires it looks like I;ll have to buy another fan - say Jaycar's Y2522.
I am heading to Geelong on Saturday and was hoping to have the installation finished before then. By the way, Geelong are forecast to have a maximum of 40-degrees on Friday - that would be a good test for how well the fan works. Luckily, the temperatures are supposed to drop to the high twenties for the next week.
Murray
Hi Murray,
If it is a true 3 wire brushless motor the only way it can be run is with a motor controller, as it needs to have the power alternated between all three wires - see article here https://en.wikipedia.org/wiki/Brushless_DC_electric_motor
It cannot run from only two wires.
Pete
Thanks. I was pretty sure that was the case.
When I get down south it looks like I'll have to buy another fan. YX2522 looks to be most suitable as it is supposed to run in a dusty environment. Providing that it only has two leads - Jaycar's catalog doesn't state how many wires.
Murray
The third wire is used for PWM speed control. I would have thought that leaving it open would allow the fan to run at maximum speed, but maybe not. What voltage do you measure between the yellow and black leads?
BTW, you might be disappointed to find that the Manufacturer's Suggested Retail Price is only 12USD whereas Jaycar stung you for AU35.
http://www.jaycar.com.au/Electromechanical-Components/Fans-%26-Accessories/Axial-AC-DC/120mm-Super-Long-Life-Low-Noise-MagLev-Bearing-Case-Fan/p/YX2584
http://www.gelidsolutions.com/products/index.php?lid=1&cid=2&id=21&tab=1 (product page)
http://www.gelidsolutions.com/products/guides/flyer_gamer_web__.pdf (datasheet)
http://www.gelid-solution.com/contact-us/ (manufacturer contact details)
Edit: The manufacturer's page is confusing. Apparently speed control is achieved by regulating the supply voltage with a supplied (?) voltage regulator.
Therefore the third wire must be the tacho output but I don't see any mention of it.
Here is the standard PC pinout for 3-wire and 4-wire fans:
http://www.allpinouts.org/index.php/Motherboard_(CPU)_4_Pin_Fan
-- Edited by dorian on Wednesday 30th of December 2015 09:05:02 PM
These brushless fans incorporate Hall Effect sensors and a commutation IC. No external commutation control is required.
How real electric motors work (Brushless DC motors):
https://newt.phys.unsw.edu.au/hsc/hsc/electric_motors6.html
Photo of fan innards, including commutation IC:
https://newt.phys.unsw.edu.au/hsc/hsc/real_motors/large_images/DSC00154.jpg
LB1962M Single-Phase Full-Wave Driver for fan motor:
http://www.onsemi.ru.com/pub_link/Collateral/LB1962M-D.PDF
A Simple PWM Generator for Fan Speed Control:
http://www.nidec.net/apps.htm
-- Edited by dorian on Wednesday 30th of December 2015 06:33:01 PM
Not sure if it is possible to buy the Gelid type fans from overseas - world wide delivery is from China but Australia is not mentioned.
Anyway, I might check out one of the local Computer Fairs to see what fans they have. Overwise I'll have to go with another Jaycar one.
BTW, this has shown that the wiring circuit given by 'dreampod' will not operate fan YX2584. I wonder how many others have been caught out.
Murray
I just retrieved the packet that fan YX2584 came in - there was no mention of a speed control being required on it, nor were any instructions provided. Apparently speed controls are already integrated in the computer.
Also, checking Jaycar's catalog with a magnifying glass reveals that all the 120mm fans, except one 12-Volt one are brushless - ie, they all require a speed control. The exception is YX2518 which although specified as being 12VDC with two wires the writing on the motor hub states that it operates on 240-Volts!
YX2522 that I thought may be suitable also turns out to be brushless.
How have other people managed to fit 120mm fans in their vans?
Another thought was to parallel several small fans but most of them in Jaycar's catalog are also brushless. Some of the others have only sleeve bearings rather than ball so only have a finite life and probable more noisy.
Anyway, I will have a look around Geelong while we are down there - and hope that we don't have a number of 40-degree days to test the refrigerator out.
Murray
-- Edited by Long Weekend on Wednesday 30th of December 2015 09:44:04 PM
Hi Dorian - we double posted at the same time.
Yes, I still have the plug and attached cable. There are no pin numbers on the plug, red is center with black and yellow on each side. It is polarised by two raised ridges on each side to fit into grooves in the socket. As mentioned I cut the plug off and run the red and black through a two pin polarised plug and socket - the locking type so that vibration won't separate them.
I checked eBay - most of the fans on them are also brushless, that is, require three wires. The two wire ones all seem to be sleeve bearings.
The only thing I haven't tried is to connect the fan direct to the 12-Volt supply rather than through the harness I made up.
I wonder how come others seem to have installed fans in their fridge enclosure without any problems?
Murray
-- Edited by Long Weekend on Wednesday 30th of December 2015 09:58:11 PM
The three wire brushless motors are essentially a 3 phase motor that needs to be run through an electronic controller which will controll direction and speed. The brushless fans others have used are 2 phase motors that can be run without a controller, many of these are computer fans.
This article may help with the technical aspects: https://en.wikipedia.org/wiki/Brushless_DC_electric_motor
edit typo
-- Edited by madaboutled on Wednesday 30th of December 2015 11:56:28 PM
Hi Murray,
Is there an Altronics nearer to you? They have a mag-lev 120mm fan for $25.95 which is definately 12vDC, even has original documentation link.
http://www.altronics.com.au/p/f1165-sunon-120mm-12vdc-maglev-bearing-fan
Regards
Pete
For my 'Absorption Fridge' I've tried numerous commercial fans and as Arnie said in 'Spies Like Us' "they were all bad".
So I made up my own.
I sourced quality 3 large size computer case fans from my local computer shop AUD$11 each, and,
A quality pipe mount thermo switch from Senasys in the USA US$11.75 http://www.senasys.com/shop/product/12-sealed-thermostat-switch-431-301a820f/
I used silicone sealant to glue the case fans to the external vent with a small recessed easily accessible kill switch hidden in the vents.
Using a cheap InfraRed Thermometer from SuperCheap Auto AUD$27 I measured the temperatures of the pipes leading into and out of the radiator part of the fridge.
Having chosen a suitable location on the pipe work I then measured the outside diameter of the pipe with my cheapo vernier calipers and ordered the appropriate temp and diameter thermo switch from Senasys.
Wiring was simple enough connecting to the existing terminal strip that has the 12 volt power to the fridge, via a fuse, then the kill switch, then the thermo switch, then the fans.
Less than $50 (I already had the tools) and it works super well. When the temperature gets hot the fans turn on. They are super quiet whilst sucking out the hot air from the radiator area. Previously the fidge simply couldn't cope with temps over 30C now it works perfectly even on 40C+ days.
PS. I tried the Jaycar type thermo switches and they simply don't work. They are flat and don't have the proper surface contact with the pipework. Any attempt to strap the flat type to a pipe using something like a hose clamp results in the clamp acting as a heatsink which draws away heat from the switch so it doesn't work. Those flat type are also very delicate and the flat face can be deformed easily which destroys them.
-- Edited by Hylife on Thursday 31st of December 2015 12:59:15 AM
-- Edited by Hylife on Thursday 31st of December 2015 01:06:37 AM
Here is a teardown of a 4-wire fan:
www.pavouk.org/hw/fan/en_fan4wire.html
All computer fans in use today appear to be brushless. That goes for 2-wire, 3-wire and 4-wire fans. The difference is that the 3-wire fans provide a tacho output on the 3rd wire, and 4-wire fans provide a PWM based speed control input on the 4th wire. All have built-in electronic commutation.
The Gelid documentation is crap, but it appears that it is a typical 3-wire computer fan with a tacho output, so it should run with only two wires. The manufacturer supplies an additional electronic voltage regulator to vary the supply voltage (all for US$12 MSRP), presumably from 5V to 12V. 5V is the minimum start voltage and is probably the supply voltage for its internal commutation IC. It appears that Jaycar gouges its customers by doubling the MSRP and deleting the voltage regulator.
In short, the YX2584 fan should work with only two wires.
Here is the same fan on eBay for US$12:
http://www.ebay.com/itm/GELID-WING-12-120mm-Quiet-UV-Reactive-Soft-Rubber-Mount-Gaming-PC-Case-Fan-Green/181097889074?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140602152332%26meid%3Da0a893b5292449c6905910378c776ab2%26pid%3D100011%26rk%3D2%26rkt%3D10%26sd%3D160372082111#ht_6992wt_942
The listing states that you can connect your 3-pin fan cable to a standard 4-pin PSU Molex connector, ie only the +12V and Ground wires are required.
-- Edited by dorian on Thursday 31st of December 2015 06:11:38 AM
CADPete
We do not have an Altronics outlet here in Canberra. But looking at Altronics web site there is an outlet in Geelong - actually within walking distance across the river from the caravan park where we are staying. Parking in that particular street is pretty tight so I will take a stroll over the bridge.
Thanks for the info.
HYLIFE
Very impressive setup. May I ask why three fans? Others seem to get by with only the one.
Also I see each fan has three wires. Are they powered by some sort of controller?
I take your point about the thermostat. The Jaycar one slithered everywhere while I was strapping it onto the pipe. I did wonder about the flat base going onto the rounded pipe but then figured if Dreampod had used one it must be alright. Nonetheless, I'll consider buying one of the Sensys ones, probably the same one as in your photo.
DORIAN
I have added the Gelid fan onto my watch list on eBay. When we return from Geelong I'll look into it further. I did notice that a controller is not included with that particular fan so I might have to chase it up separately.
Also, some further experimenting may get the YX2584 to work.
ANYWAY
We will be on the road on Saturday, two nights in Seymour then 14 days in Geelong. So it looks like everything will be on hold until our return in the second half of January. Pity, because Geelong always has several days over 40-degrees during January but I guess for this (next) year we will just have to make the best of it. But I imagine that there will still be more hot days ahead in January and February to make the fans worthwhile.
Murray
Pete,
Whoops! Just had a look at the Altronics link for the fan. While it does have two wires it is a 240-Volt fan!
Actually, the heading does state it is 12-Volt but the specifications on the motor hub states 240-Volts. I'll have to physically check one to see what is correct.
So back to the drawing board.
People have been putting 12-Volt fans in their fridge cabinets for years now, so why am I having trouble with my set up?
Murray
-- Edited by Long Weekend on Thursday 31st of December 2015 11:20:18 AM
dibs
Photo is generic Murray, Sunon part number does not match Sunon part number for 12V fan!. If in doubt double check with the store.
LongWeekend <quote> May I ask why three fans? Others seem to get by with only the one. </quote>
Whilst the absorption fridge process is simple enough, it is quite convoluted in its pipe works. Our needs relate to the beginning of the process where the ammonia and water mix is heated to an evaporation point and then immediately must be cooled slightly, relying on heat radiating away passively from the 'condenser' fins. This is why they don't work in high temp climates.
The more air you can draw over the condenser fins the faster the ammonia/water separation takes place further in the pipework and the better cooling from the ammonia.
You could always start with one fan and add more later. I bought the 120mm sized units because they are almost silent running with the bigger blades and rather than mounting them somewhere in the cavity space I chose to have them directly expel the cavity air to the outside environment.
LongWeekend <quote> Also I see each fan has three wires. Are they powered by some sort of controller? </quote>
As Dorian mentioned, computer fans with three wires provide RPM feedback to the motherboard which can be used for temperature Vs fan speed control. In my situation I only used the red and black wires and trimmed off the yellow ones. The controller is the thermo switch clamped to the pipework. Senasys have these switches available for different pipe sizes and temperature switch points, so on choosing where you will fit the switch (required space) measure the outside pipe diameter and the operating temperature at that point with your vernier caliper and IR thermometer and order what suits your fridge.
I would have preferred to support an Aussie business to source the thermo switch from but could not find anyone selling a quality unit.
Follow the link here to see the Senasys range using the drop down boxes:- http://www.senasys.com/shop/product/12-sealed-thermostat-switch-431-301a820f/
-- Edited by Hylife on Thursday 31st of December 2015 05:45:45 PM
If you go to the Jaycar cattledog you will see:
Black - earth
Red - 12 V
Yellow - tacho output (1 pulse/rev)
If you have not stuffed the electronic circuitry, just roll back the yellow and it should work.
-- Edited by PeterD on Thursday 31st of December 2015 05:48:47 PM
For Pete,
I'll be able to hold one of the fans in my hand sometime in the next week so will make sure that it is indeed two wire 12-Volt.
For Hylife,
I have checked out the thermostats from Senasys. It looks like the type 430 would be better than the type 431. The difference being the 431 has fly leads while the 430 has quick connector tabs like the Jayco thermostat.
I measured the pipe on our fridge and it was 22mm. Converting that to Imperial comes to close to 7/8th-inch and that will be the mounting bracket. Also converting 70-degrees Celsius to Fahreheit comes to 158-degrees F.
Murray
-- Edited by Long Weekend on Thursday 31st of December 2015 06:02:40 PM
Yes, I saw that the yellow was the tacho and I ignored that. As far as I can be certain I had the polarity right - red positive and black negative on all my wiring and plugs.
Anyway, we are in the process of packing up ready to head off on Saturday so will leave everything until we return back home.
By the way, Geelong had 40-degrees today - just the weather to utilise a fan to help the fridge along.
Murray
LongWeekend, I chose the 12" flylead version because of the space constraints at the back of my 20 year old Jayco's fridge, and, it meant that I could keep the wiring tidy knowing that their OEM leads would not have degradation problems with the close proximity of the radiating heat.
The switches do come with the pipe clamp to match the outside diameter of your pipe, although I had to squeeze it's open ends together a bit. So long as you consider the fitment location and how you will route your wires it really is an easy upgrade job. I used ordinary spade connectors (crimped only), but with a short length of heatshrink tubing for protection from shorts and to prevent unwanted contamination or disconnects.
I'm in hoppers so yes it was hot today.
-- Edited by Hylife on Thursday 31st of December 2015 06:46:00 PM
On a second look it seems that type 430 has a flat base while type 431 has a curved - at least that what it looks like in the picture.
How did you order yours from Senasy? When I tried to place an order I couldn't get past the country - it would only accept USA or Canada. When I typed Australia in the country box it simply went blank so I couldn't get any further. They accept PayPal so there was no problems with payment.
By the way, for anybody who wishes to order one of these thermostats the fly leads come in two lengths - 12-inches and a massive 72-inches. That's 6-feet in the old language!
At least tomorrow will be a bit cooler for you. We will be in Geelong for two weeks so expect that there will be another 40-degree day before we leave. One year it was 45-degrees on one day - the hottest in the state.
Murray
That's funny Long Weekend, all the measurements are in the old language
Have done this modification on our van using an old computer fan, it makes a difference
I too had that on-line ordering issue so I sent them and email and they replied back that their online store could only process local orders but that they were only too happy to supply overseas if I could give them with what info they needed.
Send off an email to:
Karen Fenimore
info@senasys.com
EG: Part number, description, quantity, shipping address, credit card details.
I proceeded through the online system drop down choices, added them to the cart and then I took a screen copy of the cart and saved that as a picture file.
http://www.senasys.com/shop/product/12-sealed-thermostat-switch-431-301a820f/
I then attached the picture file to my email order message so there could be no confusion as to exactly what I wanted to order.
They processed the order via PayPal. :) and I received the goods in approx a week and a half.
Remember, that unlike the rest of the world, postage costs in the USA (USPS) are very expensive, and for international freight most businesses want tracking, so will only use the Priority Mail service which is US$26.50.
If you have some GN friends that might also be considering the same mod then it is worth combining an order to spread the freight costs. The box they came in could easily fit a dozen switches.
The switches only cost US$11.75 each, but even with the added cost of freight it was still worth it because as I've said before, the flat surface thermal switches such as you can buy locally from Jaycar simply don't work properly on a round pipe and are far too delicate for our needs, and no one sells pipe-mount units in Oz.
For my 20 year old fridge in my Jayco I had the fridge running for an hour or two on a normal 25C day and using the InfraRed Thermometer measured the temps at different places along the pipework close to the condensor grills.
At my chosen mounting locations the pipes are of two outside diameter sizes, 5/8" and 7/8". Unsure of which would be more sucessfull in switching on and off as required I ordered a 431 5/8" close at 125F and a 431 7/8" close at 150F.
I am currently using the 431 7/8" close at 150F and have it mounted on the pipe leading into the condensor grill as it comes up from the heating area. It seems to be the right choice for my setup.
Hylife looking at your photo above I can understand the operation with the switch and fans. As your fans sit in the picture can you do a wiring diagram and post it please
When you run your fridge for the time to test the temperature what source did you use or does it not matter.
Were you looking for the general operating temperature and any thing higher the fans would cut in.
Did you pick up you 12 volt feed and negative as it came from your battery and could you use any 12 v source to provide power.
This is all new to me but willing to learn thank you.
-- Edited by CC Bear on Saturday 7th of January 2017 10:58:30 PM
There is already a 12V supply at the bottom rear of the fridge. Goes to a small terminal strip and then on to the 3 way switch at the front.
The 12V normally is of p!ssy little wires that are not big enough for the 20+ amps that 3ways draw.
I wired heavy duty 6mm direct to the vans house 100AH deep cycle (with a 30amp self resetting circuit breaker from Jaycar), that way there is always sufficient juice to the fridge when on 12V, even when stooped for lunch with the car not running (have a DC-DC charger for car to charge house batt whilst driving).
Tapped into the 12V at the small terminal strip in the back of the fridge. Positive goes to a fuse, to the thermo switch, then to the fans (all in parallel). Neg goes straight to fans neg.
Used a cheapo thermometer gun bought at SCA on a hot day to measure MY system pipes at various locations and ordered the switch based on that.
Your fridge will have different temps so order your switch 'turn on temp' specifically for your fridge, after you have measured your pipework at a few places whilst running on a suitably hot day.
Thank you have the general idea, will get the thermogun in the next couple of days and check the temperatures over the rest of the week. Have ordered the fans so they should be here next week. Cheers
another question I take it when you ran the new wire from the van battery you disconnected the charge wire ( at the fridge ) coming from your tug plug.
-- Edited by CC Bear on Sunday 8th of January 2017 10:15:19 PM
Throw in another here your 6mm wire is it 6 mm auto, 6 mm square or 6 B & S.
removed question answer in previous post thankd
-- Edited by CC Bear on Monday 9th of January 2017 08:32:54 AM
-- Edited by CC Bear on Monday 9th of January 2017 11:49:13 AM