Has anyone fitted temp control unit to an Engel?

[CraigE]

Hi,
I have been doing a bit of reading about changing the setup on an Engel from set thermostat control to temperature thermostat control. It makes a lot of sense and should have been done this way all along. As most of us that own these know the set thermostat is not the best type of control, especially in hot areas where you may set the setting to say 2 on a hot day and due to temps dropping overnight end up freezing items you dont want to.
Keen to know if anyone here has done this and their thoughts.
The set ups I have seen are separate to the fridge. I would like to keep it in the fridge housing. Does anyone know if you could just tap in a temp control after the fixed thermostat?
I know Engel did include this in their Gold limited edition fridges, but does not help us with older models.
https://forums.energymatters.com.au/energy-efficiency/topic3828.html

DC 12V LCD Digital Thermostat Temperature Control Regulator Controller Aquarium | eBay (http://www.ebay.com.au/sch/sis.html?_nkw=DC%2012V%20LCD%20Digital%20Thermosta t%20Temperature%20Control%20Regulator%20Controller %20Aquarium&_itemId=290686773509)

[jboot51]

I've ordered a 12v-24 ac/dc controller.
I think it will work.

[p38arover]

Craig, I fitted that temp controller to my 30 year old Engel last week. It's fitted into the top panel beside the thermostat - there is just enough room.

It works well.

I also added 3 computer fans to get better air flow.

Want pics?

As the compressor runs from AC, I put a bridge rectifier in to give about 15 volts unregulated and unsmoothed DC. That powers the fans which switch on every time the compressor starts.

The temp regulator is only on the DC side. It merely switches the 12 volts DC input to the fridge. When running from AC ( which mine never does), the original thermostat is used.

[CraigE]

Ron, some pics and how you hooked it all up would be fantastic
I have added 1 fan, but would be really keen to see how you have fitted 3 fans.
Cheers
Craig



Craig, I fitted that temp controller to my 30 year old Engel last week. It's fitted into the top panel beside the thermostat - there is just enough room.

It works well.

I also added 3 computer fans to get better air flow.

Want pics?

As the compressor runs from AC, I put a bridge rectifier in to give about 15 volts unregulated and unsmoothed DC. That powers the fans which switch on every time the compressor starts.

The temp regulator is only on the DC side. It merely switches the 12 volts DC input to the fridge. When running from AC ( which mine never does), the original thermostat is used.

[Tombie]

Craig, I fitted that temp controller to my 30 year old Engel last week. It's fitted into the top panel beside the thermostat - there is just enough room.

It works well.

I also added 3 computer fans to get better air flow.

Want pics?

As the compressor runs from AC, I put a bridge rectifier in to give about 15 volts unregulated and unsmoothed DC. That powers the fans which switch on every time the compressor starts.

The temp regulator is only on the DC side. It merely switches the 12 volts DC input to the fridge. When running from AC ( which mine never does), the original thermostat is used.

Ron

Do you have any testing of cooling efficiency gained vs power consumed?
Run times are likely reduced, what is the power now consumed during those runs vs the longer run time without the induction?

[p38arover]

Ron

Do you have any testing of cooling efficiency gained vs power consumed?
Run times are likely reduced, what is the power now consumed during those runs vs the longer run time without the induction?

No, I haven't done any testing yet, Mike. I can do some quick consumption tests, i.e., measure the current drawn with the fans connected and disconnected.

The three fans I have are low power consumption computer fans, 2 small ones on the top sucking air out and one larger unit on the back blowing air in.

Craig has asked if it would be possible to configure the controller to work when the fridge is running on AC.

It should be easy enough. Probably wire it so the relay in the controller is in parallel with the existing thermostat. Turn the original thermostat to minimum, i.e., the off position. Putting the new controller in parallel would allow the old thermostat to be brought back into use if the new one ever failed.

One would need to fit a few components to provide a regulated 12v supply for the controller. That'd comprise a bridge rectifier, an electrolytic capacitor (for smoothing the rectified AC, a 12 volt regulator, and another small capacitor after the regulator - in total 4 components costing about $8 all up. I'll draw that up later.

This diagram is, I think, pretty close to correct for an unmodified older Engel. It may have errors, I took a diagram from a later model and re-drew it. I haven't finished redrawing it nor have I added the new controller.

https://www.aulro.com/afvb/images/imported/2015/01/592.jpg

[jboot51]

AC DC 12V 24V PID Digital ITC 100VL Temperature Controller 40DA SSR K Sensor | eBay (http://www.ebay.com.au/itm/AC-DC-12V-24V-PID-Digital-ITC-100VL-Temperature-Controller-40DA-SSR-K-sensor-/331392823932?pt=AU_B_I_Electrical_Test_Equipment&hash=item4d288d327c)


This is what I've ordered
My fridge runs constantly, temp controller doesn't work.
If I disconnect the temp sensor wires, the fridge will turn off.
I just need to find a suitable voltage supply inside the fridge to power this controller and then switch the contacts for the original thermistor.
I intend to mount it in/on the fridge, hoping it will also work on 12/24/240

[p38arover]

My fridge runs constantly, temp controller doesn't work.
If I disconnect the temp sensor wires, the fridge will turn off.
I just need to find a suitable voltage supply inside the fridge to power this controller and then switch the contacts for the original thermistor.


The image only shows the power supply and switched contacts connections. Where does the thermistor connect?

The older Engels use a thermostat, not a thermistor - see my diagram above).

Can you put up a pic of the wiring diagram on the side of the controller you bought?

[jboot51]

Still waiting on the controller to arrive.


Mine is the brown lid / tan body model, first of the turbo fan series, 17 years old maybe.
There are 2 connections to the main control unit.
First is maybe a 4/6 wire which goes to the on/off/temp control knob.
The second is the 2 wire which is the thermistor.
I did some tests a while ago and concluded the circuit board behind the control knob is knackered.

[p38arover]

Some crappy pix (the blur is from a large chip in the lens!)

https://www.aulro.com/afvb/images/imported/2015/01/524.jpg

The large fan is a computer fan and it blows air into the compressor compartment and across some of the condenser tubes. It draws 200mA.

https://www.aulro.com/afvb/images/imported/2015/01/525.jpg

The little fans suck air in from the side so I siliconed in a baffle at each end to prevent that. You can just make it out in the end shot of the fan bracket.

https://www.aulro.com/afvb/images/imported/2015/01/526.jpg

The type of computer fan used on the top. I reversed the fans so they'd exhaust the hot air not blow air in.

https://www.aulro.com/afvb/images/imported/2015/01/527.jpg

The temperature controller is a Willhi WH7016C. It looks like it will run on a 12V AC or DC power supply

https://www.aulro.com/afvb/images/imported/2015/01/528.jpg

Because the clips wouldn't hold the unit in place in the grille, I silicone rubbered it in.

https://www.aulro.com/afvb/images/imported/2015/01/529.jpg

[Tombie]

Thanks Ron...

[Bradtot]

Hey That controller is what I used to control the compressor clutch on my 89 Rangie. The original thermostat controller is NLA, there is an updated pn but its not the same as my 89 was in the changeover.
I must admit the little electronic controller works very very well.
I have it set to come on at 5 degrees or higher and go off at 3 degrees.
I have fitted the controller behind the last aircon vent closest to the driver but still in the middle and I can see through the vent the digits and if I need to adjust it its a quick remove of the vent and adjust then put it back..Am so so happy with this setup.
I bought 2 of these controllers and may do just what Ron has done to my engel..
Brad:)

[LandyAndy]

Brad.
I have an 80Lt Engel,reckon the fans would fit inside easy.
What sort of coin for the controller and fans????
Ebay buy I guess????
Andrew

[p38arover]

The controllers are under $20.

The fans were in a box of stuff my son had.

[p38arover]

Here is a very rough sketch of the wiring changes needed to use the controller when the fridge is running on DC. Note the fans only operate when the compressor is running and they run on power derived from the compressor supply.

Note that the fans must not be connected to earth because one side of the compressor AC supply is connected to earth.

I'll redraw it when I get back next week and I'll draw up the changes needed to run the controller when the fridge is running on AC or DC.

https://www.aulro.com/afvb/

[Bradtot]

Brad.
I have an 80Lt Engel,reckon the fans would fit inside easy.
What sort of coin for the controller and fans????
Ebay buy I guess????
Andrew

Andrew originally posted by PhillipA about the controller and how to setup yes Ebay about 25 bucks from memory.

AutoSpeed - Technology, Efficiency, Performance (http://www.autospeed.com/cms/article.html?&A=11261)
Computer fans are cheap as either 12vdc with a bridge rectifyer and cap or find a 12vac one that wires straight in.
I have the fan on the inside of where Ron has his but down on one side on my 39ltre engel same as Rons
Brad:)

[CraigE]

Some crappy pix (the blur is from a large chip in the lens!)

https://www.aulro.com/afvb/images/imported/2015/01/524.jpg

The large fan is a computer fan and it blows air into the compressor compartment and across some of the condenser tubes. It draws 200mA.

https://www.aulro.com/afvb/images/imported/2015/01/525.jpg

The little fans suck air in from the side so I siliconed in a baffle at each end to prevent that. You can just make it out in the end shot of the fan bracket.

https://www.aulro.com/afvb/images/imported/2015/01/526.jpg

The type of computer fan used on the top. I reversed the fans so they'd exhaust the hot air not blow air in.

https://www.aulro.com/afvb/images/imported/2015/01/527.jpg

The temperature controller is a Willhi WH7016C. It looks like it will run on a 12V AC or DC power supply

https://www.aulro.com/afvb/images/imported/2015/01/528.jpg

Because the clips wouldn't hold the unit in place in the grille, I silicone rubbered it in.

https://www.aulro.com/afvb/images/imported/2015/01/529.jpg

Never even thought about putting the fans on the outside. Something to consider. Thanks Ron. This needs to be put in the Good Oil section. :D:D

[CraigE]

Andy

DC 12V Digital Thermostat Temperature Regulator Controller With Warning Function | eBay (http://www.ebay.com.au/itm/DC-12V-Digital-Thermostat-Temperature-Regulator-Controller-with-Warning-Function-/390686342429?pt=AU_B_I_Electrical_Test_Equipment&hash=item5af6b87d1d)

220V Digital LCD Display Electronic Universal Thermostat Temperature Controller | eBay (http://www.ebay.com.au/itm/220V-Digital-LCD-Display-Electronic-Universal-Thermostat-Temperature-Controller-/400683553153?pt=AU_B_I_Electrical_Test_Equipment&hash=item5d4a99d181)

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Or if your want Land Andy bling fans
Blue 120mm Fans 4 LED DC 12V FOR Computer PC CPU Heatsink Case Cooling FAN 4P | eBay (http://www.ebay.com.au/itm/Blue-120mm-Fans-4-LED-DC-12V-for-Computer-PC-CPU-Heatsink-Case-Cooling-Fan-4P-/400620293450?pt=AU_Components&hash=item5d46d48d4a)



Brad.
I have an 80Lt Engel,reckon the fans would fit inside easy.
What sort of coin for the controller and fans????
Ebay buy I guess????
Andrew

[CraigE]

Ron,
What size bridge rectifier would you recommend?
Cheers
Craig

Craig, I fitted that temp controller to my 30 year old Engel last week. It's fitted into the top panel beside the thermostat - there is just enough room.

It works well.

I also added 3 computer fans to get better air flow.

Want pics?

As the compressor runs from AC, I put a bridge rectifier in to give about 15 volts unregulated and unsmoothed DC. That powers the fans which switch on every time the compressor starts.

The temp regulator is only on the DC side. It merely switches the 12 volts DC input to the fridge. When running from AC ( which mine never does), the original thermostat is used.

[p38arover]

Never even thought about putting the fans on the outside. Something to consider. Thanks Ron. This needs to be put in the Good Oil section. :D:D

On my model, there is no room inside. For bigger older models, like the pic below, there is room for fans at the bottom and Engel make a kit (so I was told over New Year by a bloke who had fitted one to his).

http://www.aulro.com/afvb/attachments/camping-tucker-and-bush-basics/89654d1421873229-has-anyone-fitted-temp-control-unit-engel-image.jpg

The transit cover I use still fits with the fans in place.


Ron,
What size bridge rectifier would you recommend?

It depends on the current draw of the fans. One can't go too high as the transformer winding supplying the compressor may not have sufficient current capacity. 1 amp should be OK. I selected one that was in a metal case that could be screwed to the metal work - no need for a circuit board. I think it's rated at 10 amps - it was in my drawers of electronic components. Something like this would do: BR106 10A 600V Bridge Rectifier | Jaycar Electronics (https://www.jaycar.com.au/br106-10a-600v-bridge-rectifier/p/ZR1320)

[p38arover]

I was just looking on the 'net for a pic for this thread and came across this.

I don't need to draw up circuit for a regulated 12 volt supply, there's one here. His fan fitting instructions put the fan at the bottom under the compressor but he has the 39 litre fridge like I pictured in my previous post.

Mine is the 29 litre and there is no room.

How to add a fan to an earlier model Engel Auto Fridge. (http://www.gpsoz.com.au/faninstall.htm)

[p38arover]

Well, I used it over the Australia Day Long Weekend (I was away for about 5 days) and found the temperature control was much improved.

However, because of where the temp probe is located vs. the location of the Engel fridge thermometer probe, there was a bit of disparity. One can put an offset into the controller to match the readings but that wasn't the problem.

I've mounted the temp probe next to the fridge's thermostat and behind the white plastic cover at the compressor end.

What I'm now considering is drilling a hole at bottom of the white panel fitting a small computer fan behind the hole. I'll draw air from the fridge interior though this hole. At the top of the panel, I'll cut a series of slots to allow the air to exhaust back into the fridge.

I'm hoping this will better distribute the "coolth" in the fridge.

I'm not sure if I should draw from the top or the bottom. Comments welcome.

[DeanoH]

Hi,
I have been doing a bit of reading about changing the setup on an Engel from set thermostat control to temperature thermostat control. It makes a lot of sense and should have been done this way all along. As most of us that own these know the set thermostat is not the best type of control, especially in hot areas where you may set the setting to say 2 on a hot day and due to temps dropping overnight end up freezing items you dont want to........................................



I must be missing something here. A thermostat is a temperature controlled switch. It turns on at a set temperature and turns off at a set temperature (differential). It's not rocket science, usually some sort of bi-metal strip coiled up or fluid expansion/contraction device to operate a mechanical switch. Why does its operation matter whether it's day or night ? Sure there are better efficiencies with cooler ambient temperatures and using fans to remove excess heat from the condenser improves efficiency especially with high ambient temps so why is the thermostats operation dependant on ambient temp ? The thermostat is inside the fridge and turns the compressor on/off according to this temp and not the outside ambient temp ?

We run two Engels in the OKA, one MF35 which is probably about 20 years old as a fridge with an attached 'cool zone' as a crisper and a MF17 used as a freezer. An external digital thermometer is connected to each. The fridge is set at a nominal 2 degrees C and the freezer at a nominal -4 degrees C. Once settled down (ie warm contents cooled) the temps vary by about plus or minus 2 degrees C depending on day or night ambients which can vary between zero and 40 degrees C and I reckon this is more about insulation efficiencies and getting excess heat away during the day.

What am I missing here ?

Deano :)

[scarry]

Ron,
Can't work out exactly where you are going to drill a hole inside the fridge,but whatever you do don't damage the evaporator.Yours is probably the gold one,the best one they ever had.Once damaged it is a throw away:(

Remember too, the original t/stat operates on evaporater temperature,not air temp.Using evaporator temperature is the best way for a cabinet to work,particularly if it is not forced draught.To do the same with an electronic controller is a PITA to set up,can be done but not good practise.You can use an electronic controller in the air,but finding the best place for the sensor in the cabinet,and the best settings is guesswork.Also setup so there is not short cycling is also important.

We use hundreds of electronic controllers,check the amp rating on the switching contacts,guessing you have done that.

Why not just fit the original t/stat,i am pretty sure they are readily available and work well.I have trend logged both my 28 yr old and my brothers 30yr old Engle and have found the temps to be very good,even with changes of ambient temps during the night.if the thermostat is turned up during a hot day,products will probably freeze once the ambient drops during the night and the refrigeration system in the cabinet catches up.I set mine and leave it,never had an issue.

The fans are a very good idea,but probably only needed during periods of high ambient temps.If the head pressure is too low during cool ambient temperatures,issues can occur,and pull down rates extended.Also power is being used for no gain.

The main issue i have find using Engles is the cabinet insulation is not great.In hot weather i make sure mine is in the shade,out of the vehicle if possible, and cover the cabinet,being careful not to restrict airflow over the condenser,with a wet towel,if possible.Also make sure the cabinet is on a hard surface so the airflow from low down under the condenser is not restricted.

[p38arover]

Hi Paul,

The original t/stat still works but I did find I needed to adjust the setting between day (when the Rangie is mostly closed up and the temp in the car is 45+ deg C) and night time. My fridge has the slight extra insulation of a transit bag. I suspect the bag's shade cloth covering the vents on the fridge doesn't help circulation.

It's impractical to remove the fridge when camped but it could be done. It's a pig to lift out from between the back of the left rear passenger seat and the storage drawers. It has to come out through the left passenger door over the seat. I put a towel over the car door window to put the fridge in shade for most of the morning.

The panel I am thinking of drilling pops out quite easily and is a cover over the thermostat bulb and pipework where it exits the fridge. See following pic taken from the 'net. My electronic sensor thermistor is behind that central plastic panel and is next to the thermostat bulb. I was going to tape it to the bulb.

https://www.aulro.com/afvb/images/imported/2015/02/1049.jpg

I am not a fridgie so I don't understand how head pressures impact on refrigeration (I see some Googling coming up). I see the same thing is mentioned in the P38A workshop manual in reference to the condenser fans coming on, either at full speed or half speed - or not at all, only under certain conditions of A/C pressure.

My plan is to improve ventilation around the compressor area - it is restricted. I'll take some pics tomorrow and add them here. My Engel sits on a hard ply floor over the wheel well, not on carpet. I was going to drill some holes through the ply so that air can flow more easily.

When I was camping last, I was shown another bloke's set up where he draws air over a dampened Chux cloth - much like an evaporative cooler - to cool the air before passing it over the condenser.

[jboot51]

Finally got time to do my mod.
My controller was shot.
The fridge would run continuously, never cycling off.
I found that if I disconnect the plug for the thermistor, it would turn the compressor off.

I used a Sestos D1s-2r-24 controller.
rated at 12-24 volt AC/DC.
This controller has a 10 year memory so long periods of disconnection should not be a problem.

A new rocker switch was installed for on/off, the red and orange wires

Additional k-type thermal sensor was installed in the original location.
To power the controller I tap into the red wire + and ran a earth to a screw on the chassis of the fridge.
This powered the controller but the fridge would not turn on unless a diode was place between the blue and purple wires as per original configuration.

The brown and black wire originally had the variable resistor and 2 resistors in parallel in its circuit.
these were replaced with 1x 12K 1watt resistors in parallel.


So far I have found a set temp of 2 degrees will give a compressor run state until 0.8 degrees and a restart of 2.3 degrees.
Run time is 1min 35 sec with downtime of 3min 55 sec


So in summary
red/orange--on/off switch---red to power the controller.
brown/black --3x 12k 1w resistors
blue +/ purple - -----led diode.


Original thermistor wires were cut and controlled by the alarm contacts.


I also replaced the fan (24v dc) with 2x 120mm fans wired in series.
Fan supply was also 17v dc at the time of testing.


the attached picture of the terminals with wires connected is not quite the finished product.
originally I powered the controller from the led supply.
this proved no good as when connected to 12v in the defender,the volts dropped to around 7.
The controller is now powered from the red switch wire and seems to working fine on 12v dc.

[CraigE]

Reviving this Post.
Hi all reviving this post as I finally have some of the parts I need, fans, thermostat controller.
From what I can gather between Rons instructions and the GPSOZ instructions is I have to make a PCB board up and wire into the circuit.
Now some of the numbers posted in the GPSOZ page seem to be outdated.
Can anyone advise on updated numbers from Jaycar as DSE dont stock them or similar as cannot find any reference to these numbers or can a pre made board be bought to these specs?
H5605 pcb (you only use 1/2 of this)
R4460 capacitor
R4705 capacitor
Z6552 regulator
Z3304 Rectifier Bridge
H2870 Box

Has anyone actually made one up and if so do you have any photos? If so can you please post?
This will be my first venture into making up a board like this, so need some clear instructions, though have replaced a couple.
Also has anyone done this for the 240v side as I also have a suitable 90-240v thermostat controller.
Cheers
Craig

[p38arover]

H5605 pcb (you only use 1/2 of this)
R4460 capacitor
R4705 capacitor
Z6552 regulator
Z3304 Rectifier Bridge
H2870 Box


DSE nos. followed by equivalent Jaycar nos.
H5605 - use some veroboard HP9540
R4460 2500uF electrolytic capacitor. Use 16volt minimum, say RE6238 (105 deg C rating)
R4705 capacitor - use a polyester 0,22uF RG5150
Z6552 7812 regulator, Jaycar ZV1512
Z3304 Rectifier Bridge, type BR105 Jaycar ZR1320
H2870 Box - just have a look for some Jiffy Boxes - maybe ones with mounting flanges HB6016

I didn't make up a PCB. I just bolted the bridge rectifier to the case and ran wires to it. I didn't think the extra bits to rectify and smooth the DC supply were necessary to just run the fans. I'll need to find the thread again to see what I wrote.

However, mine isn't running the digital controller when on 240v. I never use the fridge on 240v. I might look at doing that just for completeness sake.

If you want to use a PCB, one would normally design and etch the board to remove the unwanted copper. I suggest you look at using Veroboard. It has strips of copper and is pre-drilled on a 1/10" spacing.

https://www.google.com.au/search?q=v...w&ved=0CCMQsAQ

To break up the strips, one can use the genuine tool or do as I do - get a 3-4mm drill and use it to cut away the copper.

See https://www.youtube.com/watch?v=x4p5wD2wMjo

[weeds]

I'm interested also, I have two fridges to convert. ......

[weeds]

Going to have a crack at my 32L this week.........and than tackle the 40L

It's was a pain keeping the fruit and veg at a constant temp over the last week on the beach with not temps during the day and cool temps at night.......

Off the find the controllers I brought ages ago........pretty sure they are different to the one jboot used.

More to follow over........

[weeds]

I have two of these controllers


Digital Electronic Temperature Control WH7016C Controller Thermostat Digital Lcd, 110v, Temperature Controlling Range -58 ~ 230 ℉;, Domestic Freezer, Water Tanks, Refrigerator, Industrial Chiller, Bolier, Steamer, Industrial Equipments - Programmable Household Thermostats - Amazon.com@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41MnvUoKOTL.@@AMEPARAM@@41MnvUoKOTL

[scarry]

I have two of these controllers


Digital Electronic Temperature Control WH7016C Controller Thermostat Digital Lcd, 110v, Temperature Controlling Range -58 ~ 230 ℉;, Domestic Freezer, Water Tanks, Refrigerator, Industrial Chiller, Bolier, Steamer, Industrial Equipments - Programmable Household Thermostats - Amazon.com (http://www.amazon.com/Electronic-Temperature-Controller-Controlling-Refrigerator/dp/B00BVYAXP6)

Hmm,110V doesn't look too good,presume yours is different?Maybe 12v.

It will consume power all the time as well,but will be minimal.

Dunno why you guys have issues,i have had my Engle for over 30yrs and never had a problem and i keep a good eye on the temps:confused:

Ditto for my brother's.

Just saying….my 2 cents worth…….

[weeds]

Hmm,110V doesn't look too good,presume yours is different?Maybe 12v.

It will consume power all the time as well,but will be minimal.

Dunno why you guys have issues,i have had my Engle for over 30yrs and never had a problem and i keep a good eye on the temps:confused:

Ditto for my brother's.

Just saying?.my 2 cents worth??.


On the back it has
DC12V ticked
5A/AC220v ticked

I too have been using Engels for maybe 25 years..........

You say you keep an eye on temps, how do you do this??

Currently I have external temp gauge with the probe tied to the the basket about 1/3 up from the bottom......

These days I like to keep the veg, salad type stuff fresh, going below 3-4 degrees if life is reduced..............plus pretty much every fridge on the market these days has auto temp control.

Although I am starting to struggle working out how to connect it up the way jboot51 has........

Thinking cap is going to get a work out.

[weeds]

Here is a very rough sketch of the wiring changes needed to use the controller when the fridge is running on DC. Note the fans only operate when the compressor is running and they run on power derived from the compressor supply.



Note that the fans must not be connected to earth because one side of the compressor AC supply is connected to earth.



I'll redraw it when I get back next week and I'll draw up the changes needed to run the controller when the fridge is running on AC or DC.



http://www.aulro.com/afvb/attachment.php?attachmentid=89652&stc=1&d=1421845019


Righto Ron.......

I was hoping I could work out what jboot51 did so that I could maybe use the the wiring at the knob and connect to the same using the you have.........

Now looking to copy your install but it looks like a major effort to wire the controller into the spots you have drawn.

I assume I need to get into here, the silver box?

https://www.aulro.com/afvb/images/imported/2015/12/58.jpg

[weeds]

OK pulled said silver box apart.........

Found the 12V input although I have Red and Black.....Ron's on you drawing you picked up a grey wire for the earth......this is where I'm confused as I thought I would pick up the 12V negative. Is your grey wire the 12- ? I thought it would have shown earth or ground on your drawing.......

Totally expecting the models will have different wiring........

[scarry]

On the back it has
DC12V ticked
5A/AC220v ticked

I too have been using Engels for maybe 25 years..........

You say you keep an eye on temps, how do you do this??

Currently I have external temp gauge with the probe tied to the the basket about 1/3 up from the bottom......

These days I like to keep the veg, salad type stuff fresh, going below 3-4 degrees if life is reduced..............plus pretty much every fridge on the market these days has auto temp control.

Although I am starting to struggle working out how to connect it up the way jboot51 has........

Thinking cap is going to get a work out.

I use a digital probe to keep an eye on the temps,the sensor will sit among the product,away from the cold plate.The best way is to put the probe in a glass of water,but not practical in a cabinet such as a camping fridge.This is the most accurate way to monitor product temperatures,if they have been in the cabinet for approximately the same time period,or for over 24 hours.

Ah,so you want it to run warmer for veges,and the existing control will not go to the warmer setting.Yes that could be an issue.Mine generally runs around 2 to 4,as it has dairy products and drinks most of the time,and i set it lower if mostly drinks.Vegetables will get spoiled at these temps.



That wiring is a bit complicated,i can't read the drawing properly as it is not clear on my lap top.

Possibly you may be able to take the two existing thermostat wires and put them on 1 and 2,the switching wires, on the new controller.Just be careful as they may be 240,can't see on the drawing properly.And then power the controller from a 12v source in the cabinet.Thermister then goes into cabinet.

Good luck

[weeds]

Re-reading Ron I think I interpreted it wrong........

Maybe no need for earth as he is using the thermostat circuit so the original set up is there just incase the new set up fails. Good idea but I wasn't keen to pull the circuit board apart anymore....I did see a grey wire coming of the circuit board behind all the cables and cardboard.

Unfortunately I'm no too confidant playing with circuit board. If I could do without the fridge and had a clearly (correct) drawing I could probably strip it down more and work it all out.

Anyway as mine is still all working as it should I have come up with plan B

[weeds]

Plan B

As mine is all still working as it should I have settle with leaving all the OEM as it is.......well until I can get a look at jboot51 set up, it could be simpler than I making it out to be.

I have spliced into the 12v lead that plugs into the unit......

I than turn the fridge into say No. 4 on the dial

Ran the new probe in and the new controller monitor the temp and gives power to the fridge when required.....as the OEM knob is on colder than it needs to be the compressor starts up.

I figured a lead is cheaper than me blowing the circuit board up.

Just ran a test at 20 degrees

Now have a bottle of water with the target temp set to 4 degrees

Once it proves it self I will make it all a bit more permanent and re-install into the camper.

103623

[weeds]

Had a guy reply on another forum, thought it would be helpful to this thread.

I saw what is probably a better way of doing this...... after I had finished of course. It wouldn't have worked for me as the circuit board was fried anyway.
It used the same temp controller, but that was used to switch a relay that the power supply was run through. The temperature sensor is then dropped into the fridge and the dial on the fridge set to max cool. The controller uses bugger all power, around 0.25A.


Disclaimer: Let me first state that I'm not an electrician. My electrical training is a big fat 0, I mucked around with car electrics once and set the dash alight, so, if you blow yourself up or burn your house down, then don't blame me.


I have been having intermittent issues with the old Engel. When you open the lid, the travel bag has a round insert that puts pressure on the dial thermostat. this isn't good as around 12 years ago now the dial thermostat broke away from the circuit board and the fridge wouldn't work at all. I repaired it then by bridging the damaged connection with a thin piece of wire and it worked fine for a long time.
Lately the accuracy of the dial thermostat has been a bit hit and miss, some days it will get things cold, the next they are frozen, all the while the dial hasn't moved. When it is used as overflow drinks storage during Christmas the dial gets nudged into the freeze zone by certain people that want a slushy to drink, but it does my beers no favours at all.

So I was ebay-ing and found 12v digital thermostats with a remote thermocouple thermometer for bugger all. A few people I know have used them before and for $15 delivered, so figured you can't go wrong. As my fridge was working less that optimally I didn't have much to lose either.

So, here is the fridge: I'm going to make the little box run it.





There is a bit of messing around to gain access, a bunch of small screws around the bottom of the case and a few that hold the top cover on.



Once the top cover is off, flip it over and you have access to the temperature control board/on/off switch. You can see my repair on the temp controller (thin black wire)
It was here that I made a discovery that made me swear a lot. An Engel will run off 12V DC, but as far as I can work out, just about everything inside it runs of 20V AC :evil: . This is a pain in the bum as the simple job of wiring in a 12V DC component suddenly isn't that simple.

What I did discover is that the black and brown wire are the on/off and the red/yellow wires are the on/off for the compressor and switched by the thermostat. I also found that the circuit board has deteriorating and some of my isues were probably down to bits of the printed circuit breaking away from the circuit board. A few more bridging connections will get some more life out of it.



So, as I found out after poking around with a multimeter for a while, simply taking the connections off the control circuit board and inserting the new thermostat wasn't going to work. I needed a plan B.

Off came the cover and out came the power supply. There are only a few screws holding it in, but you have to slide it out vertically. Once it is out then all the screw holding the cover plates on are easy to access.



The only 12V I could reliably find was the 12V input from the power connector, so I spliced into that and ran it to the new thermostat.

The switched circuit in there thermostat didn't care what voltage everything else was running so I soldered 2 wires onto the old dial thermostat circuit board and ran them to the new thermostat. The black/brown wires stay on the old dial thermostat circuit board and the dial is set to Freeze and works as the on/off switch.

It is not the ideal arrangement, but this way the fridge can still run on 240V, just not with the digital thermostat running things. Today I found that you can get a 12V DC and 110/240V AC digital thermostats for the same price and they look exactly the same as the one I used, so I'll probably upgrade and have it all digital, although I'm not that keen on messing around with the 240V side of things. (http://www.ebay.com.au/itm/351212376282?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

Other than tapping into the input power, I have left the entire main power board and power supply alone. It still works as intended, it is just now switched on and off by the new digital controller.



After a few hours messing around, soldering and insulating, success! :D :D

The new thermostat thermocouple has been run in behind the plastic cover plate inside the fridge, fridge will run on 240 and 12V power and gets cold. More importantly I didn't go up in a big blue flash!. I did have to move the thermocouple as it was zip tied to one of the cooling tubes. It said the fridge was getting really cold really quickly though. I moved the thermocouple and silicon-ed it to the side of the case, so hopefully those readings will be more reliable now.

The digital controller has a few parameters you can adjust, so it now has a set point that is easy to adjust, it also has a tolerance so it can turn on again if the inside temp gets 1 degree or 40 degrees over the set temp (currently running 3 deg) and the whole time it displays the inside temp.

Yes, I do need to more permanently mount the digital thermostat, but I'll wait until the multi voltage one arrives. The plan is to cut out the old dial and make up a little bracket so the new one sits up at a bit of an angle and can be viewed easier. I also need to replace the little 12V computer fan as it had died.

But it was all done for under $15.... and a bunch of wire off cuts and a really old soldering iron I had in the shed.



All wired up with the new 12/240V controller and it worked beautify, until I had 12V and 240V circuits plugged into the fridge controller at the same time. As all the magic smoke escaped from the controller I realised the point the really poorly translated engrish instructions were trying to convey:(. Apparently, although it is a 12/240V controller, you can't have a connection to power to both circuits at once. The power will run to earth through one of the unused control circuits and the circuit board fried.

So, onto eBay and another $15 and the controller was here in a bit over a week, unfortunately I was in Darwin and couldn't do anything with it. The whole project got pushed into the corner of the shed for a while so I could think about it.

Plan B was to have a switch for 12V and 240V, The switch would completely isolate each circuit. So a trip to Jaycar for 2 x guarded 2 pole switches and I'm back in the game! It probably isn't the most elegant solution, but it was quite cheap and still it works.

I can leave both power cords plugged in, so if we get to somewhere that has 240 available, I can easily plug into that without pulling the fridge out of the vehicle to get to the plug. The guards hopefully will ensure that no one accidentally turns something on that they shouldn't.

[

The fridge now works a treat! I can set it to anything from +120 to -40 (not that it will ever get that cold), and what tolerance I'm happy with, as well as the max and min temp you will allow the thermostat to be set to (which will stop someone cranking it down to -30 and the fridge working it's ass off trying to get there. I found that 1 degree +/-3 degrees works really well and you can see at a glance what the fridge is running at.
Before I could set the dial and roll the dice as to if I'd have cheese in a bottle and warm beer, frozen milk and popped cans or something in between cheers.

[Tank]

Can someone who has purchased one of these controllers off e-Bay tell me how long delivery took and were there any hassles, Regards Frank.

[jboot51]

This is the one I used.
AC DC 24V Digital Temperature Controller PID 25DA SSR K Thermocouple Probe | eBay (http://www.ebay.com.au/itm/AC-DC-24V-Digital-Temperature-Controller-PID-25DA-SSR-K-Thermocouple-Probe-/231729227894?hash=item35f4236876:g:KxsAAOSwg3FUo2Y U)


24v AC/DC
I never used the solid state relay


Shipping did take a while, maybe 3 weeks.




Mine has been running 24/7 without any problems.
I just need to confirm where I picked up the - for the controller supply.

[Ranga]

Hey Tony, might need to pick your brains to fit one to my Trayon internal upright fridge ;)

[jboot51]

Hey Tony, might need to pick your brains to fit one to my Trayon internal upright fridge ;)
Give me a call sometime and we will give it a go.

[CraigE]

Finally getting around to putting the temp controlled thermostat and fans in the Engel. I have the diagrams from Ron for the MRFT=530A-A4. Mine is however the 60 litre MRFT-5600-G4 and the wiring is quite different. Has anyone done the 60 litre and have the wiring diagram or where they tapped in? If so can you post here.
cheers
Craig

[CraigE]

OK I think I may have it sussed and maybe easier than I thought.
The main power wire that requires splitting is the 12v Red main wired so that is easy.
Just have to determine the Neutral(240v) Negative 12v common wire. This is the one that needs to be split and run to thermostat controller using 2 wires. From what I saw today this must be Orange but will confirm in the next day or so for the 60 litre Engel. This one just needs to be tapped into.
Hopefully I have this right as there seems to be no info or wiring diagrams on the 60 litre Engels easily available.

[weeds]

Yes Engel have manage to restrict technical info......

I went a different 'easier rout' and it working well.

[CraigE]

OK finally got around to setting it up just before Easter. Seems to work well, though have only used once.