Thread: Has anyone fitted temp control unit to an Engel?

Originally Posted by 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

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

Ditto for my brother's.

Just saying….my 2 cents worth…….

Originally Posted by scarry

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

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.

Originally Posted by 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.

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?

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........

Originally Posted by weeds

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

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

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.

ImageUploadedByTapatalk1451446827.998205.jpg

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 . 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/351212376...%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!

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.

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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.