Danfoss AEO controller

[senormechanico]

As a retired electronic tech (now Bernina sewing machine servicer) I have had a couple of ocilloscopes and have looked at the refrigerator "black box" output.
Actually, I have fixed a couple of those "black boxes".

The output on my old system (since replaced about ten years ago) was 3 phase, pulsed 12 volts DC to the BD50 compressor. The duty cycle was varied for speed.
No AC was involved, but the inductive effects of the motor probably kicked back a bunch of it.
I would not be surprised if that is a major source of the wideband RFI everyone experiences from their refrigeration units.

Usually what fails on those boards are either circuit board solder connections due to heat cycling, or the output FET's themselves.
There is nothing proprietary about the parts that usually fail, but I don't repair these for others, so please don't ask.

I see no reason for the current design to having been changed to actual AC output, and thus see no conflict in the Secop statement.

[Typhoon]

Originally Posted by senormechanico

As a retired electronic tech (now Bernina sewing machine servicer) I have had a couple of ocilloscopes and have looked at the refrigerator "black box" output.
Actually, I have fixed a couple of those "black boxes".

The output on my old system (since replaced about ten years ago) was 3 phase, pulsed 12 volts DC to the BD50 compressor. The duty cycle was varied for speed.
No AC was involved, but the inductive effects of the motor probably kicked back a bunch of it.
I would not be surprised if that is a major source of the wideband RFI everyone experiences from their refrigeration units.

Usually what fails on those boards are either circuit board solder connections due to heat cycling, or the output FET's themselves.
There is nothing proprietary about the parts that usually fail, but I don't repair these for others, so please don't ask.

I see no reason for the current design to having been changed to actual AC output, and thus see no conflict in the Secop statement.

The new Danfoss controllers we use are "RF" whisper quiet , I checked them on our Oscilloscope. They also have significantly less leakage to ground . They do not use the same circuitry as the old units and do not have the cooling fins on the back . As far as I know we are the only company using them in the marine refrigeration business. Danfoss #101N0650

Regards John
www.coldeh.com

[Richard Kollmann]

Originally Posted by OzePete

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

Originally Posted by Richard Kollmann
Rich, The Cool Blue is the most energy efficient eutectic holding plates system because it can be operated with Danfoss BD35 at 2000 Rpm without a speed change.

Pete’s comment Really! what is the logic and evidence behind this vague statement or are you also of the school that believes a smallercompressor is more efficient because it has a lower A/H rate!

My reply the logic is a BD35 Compressor selection would be based on volume of heat removed from insulated box per day. Under the right heat load condition with a Technautic Cool Blue BD35 compressor and eutectic plate will never need a speed over 2000 rpm. Many boaters have reported a 50% energy reduction and still maintaining desired box temperature. Any school you went to will show you that reducing energy to get the same volume of work done is more efficient.

My Question Have you ever heard of the BD compressors while running shutting down on a low speed LED signal?

Pet’s Comment Where was the reference to; BD compressors while running shutting down on a low speed LED signal? Read what was said Richard and if any one in the industry has not witnessed that then they are simply quite inexperienced!

My reply Pete you posted this on your post 42 The minimum speed is 2000 RPM but not recommended as most compressors will shut down instantly if the speed momentarily drops to 1800. Drop in speed a few hundred revs can occur if there is a sudden voltage drop due to other uses of the battery supply. Running at 2000 RPM can allow nuisance tripping so best
If anyone has ever seen this 4 LED flash code because on a drop in Rpm in lighten the rest of us.

Pete also talks about the need for soft start modules. Absolutely I do and hopefully by now you have worked out how they function and the benefits or are you still suggesting that the DOL modules are/were without major failure problems? Because if you think the old DOL module type is ok, there are many thousands of peed off users out there who have spent big dollars on replacing those crap things, and who would totally disagree with you!


My reply is there are many thousands of pleasure boat refrigerators that were designed for Danfoss BD compressors and if installed correctly do not have the need for Soft or Hard Start control modules. You can put Band Aids on a weak design moving trouble somewhere else, another bad idea. In the last year I have tested over 100 modules finding at least 40% failures due to reverse voltage spikes and over heated power circuits. As long as designers and installers push the design envelope on a system’s high pressure and compressor temperatures, control modules will fail. If you know of a compressor that can avoid these problems. then you should share that knowledge with all of your readers instead of making asinine statements about things that you don't seem to understand.

[a64pilot]

Originally Posted by senormechanico

As a retired electronic tech (now Bernina sewing machine servicer) I have had a couple of ocilloscopes and have looked at the refrigerator "black box" output.
Actually, I have fixed a couple of those "black boxes".

The output on my old system (since replaced about ten years ago) was 3 phase, pulsed 12 volts DC to the BD50 compressor. The duty cycle was varied for speed.

I would expect pulsed DC as it pretty well emulates AC, it can be run through a transformer and voltage changed where pure DC cannot for instance.
Remember vibrators who’s purpose was to make pulsed DC?

[a64pilot]

Originally Posted by ColdEh Marine

The new Danfoss controllers we use are "RF" whisper quiet , I checked them on our Oscilloscope. They also have significantly less leakage to ground . They do not use the same circuitry as the old units and do not have the cooling fins on the back . As far as I know we are the only company using them in the marine refrigeration business. Danfoss #101N0650

Regards John
www.coldeh.com

From what I have read, the old controllers are being phased out, everyone will be using them, whether they want to or not, they are being shipped as old stock is depleted.

I think Richard posted a link to that SB a while back?

[SV THIRD DAY]

Originally Posted by a64pilot

From what I have read, the old controllers are being phased out, everyone will be using them, whether they want to or not, they are being shipped as old stock is depleted.

I think Richard posted a link to that SB a while back?

Originally Posted by ColdEh Marine

As far as I know we are the only company using them in the marine refrigeration business. Danfoss #101N0650

The old controllers with heat fins were out of production now two years ago. I posted about it in May 2016. So the only companies using the old controller or selling them as replacements for failed units are just moving out old inventory. Some of the larger guys are buying pallets of compressors and controllers at a time, so they supply chain takes a little time to change over inventory. But the new quiet RF controllers are now the standard for Danfoss.

http://www.cruisersforum.com/forums/...le-165725.html

[senormechanico]

Originally Posted by a64pilot

Remember vibrators who’s purpose was to make pulsed DC?

Nowadays, a solid state version of those vibrator power supplies (as in old tube type car radios) is called a SMPS, or Switch Mode Power Supply.
They are everywhere, light weight and quite efficient with power.

[a64pilot]

Originally Posted by senormechanico

Nowadays, a solid state version of those vibrator power supplies (as in old tube type car radios) is called a SMPS, or Switch Mode Power Supply.
They are everywhere, light weight and quite efficient with power.

You may laugh, but almost all of my electronics knowledge came from the 60’s as a kid experimenting and building my own bread boards and printing my own circuit boards, but before EEPROMS etc. in the 60’s electronic supply stores were everywhere and things were still repaired, then later things were trouble shot down to boards and boards replaced, now it seems not much is repaired, assumption is with microcircuitry, it’s just not repairable?

Funny story on the word solid state. The new GE turbine engine is based heavily on the old Walter engine, made in Czechoslovakia etc. The autostart box on the Walter was problematic with old style relays and even a fuse in it. I kept asking the GE Czech Engineers if the new box would be solid state, but never getting a real answer, finally the Chief Engineer said, yes it will be rigidly mounted, is that what your asking?

[OzePete]

Originally Posted by OzePete

A good play on words!!
You could say that all three phase motors are 'electronically comutated DC brushless motors. What I stated and what you believed is correct, Secop are just saying the same thing differently! (That is why there are three pins!)
And yes to properly analyze your AC supply you need a CRO as there is more than voltage and frequency to check if you want the whole story.

Cheers OzePete

Confirming and adding to what I quoted here. There is no such thing as a DC motor as such. A motor has to have alternating polarity to operate.. simple! Some are called DC because they are supplied DC but that DC is inverted to AC either electronically or via a commutator BEFORE being fed to the AC motor.

Testing of the 3 phase AC driving these little compressors is best done with the compressor running otherwise if only reading the output of the Motor Driver module alone, it will appear to be DC.

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[wsmurdoch]

Originally Posted by a64pilot

OK let me explain why I don’t think most Cold Plate systems actually phase change each compressor cycle.
The phase change occurs at one set temp, you can of course vary this temp by the mix ratio of the fluid. So there ought be only one set temp that a system would run properly at, there is no adjusting a thermostat without changing the freeze point of the solution, if you need colder temps, if you set it colder than the solutions melting point, it doesn’t melt.
The proper phase temp needs to shift with thermostat settings, and I doubt many do that.
I’d suspect many if not most of us only achieve a partial phase change at best, but that is just my theory.
If I’m right, then a proper Eutectic system isn’t easy to achieve, takes some tuning.

I'm not sure the phase change occurs at one set temperature in a normal propylene glycol - water filled "eutectic" plate.

Here is Dow's freezing point data. When a PG - water mixture freezes, it freezes into a mixture of liquid PG, liquid water, and ice.



Let's say I fill my 5 gal cold plate with 8 lb of PG and 32 lb of water. It will be 20% liquid PG and 80% liquid water.

I cool the mixture to 0F. From the chart the liquid is now 37% PG and 63% water. Part of the water has frozen to ice. So, the cold plate now contains 8 lb of liquid PG, 13.6 lb liquid water, and 18.4 lb ice.

I then raise the temperature to 10F. From the chart the liquid is now 30% PG and 70% water. So, the cold plate now contains 8 lb of liquid PG, 18.7 lb of liquid water, and 13.3 lb of ice. As the temperature rose, 5.1 lb of ice melted and absorbed 734 BTU (at 144 BTU/lb).

Finally, I raise the temperature to 20F. From the chart the liquid is now completely melted. As the temperature rose, 13.3 lb of ice melted absorbing another 1915 BTU.

Of course a little more heat is absorbed as the liquid PG (0.5 BTU/bl/F), the liquid water (1 BTU/lb/F), and the ice (0.5 BTU/lb) are warmed. But, most of the heat is absorbed by melting the ice suspended in the PG - water solution.

So, my cold plate when operating between 20F and 0F can absorb a little less heat than a 20 lb bag of ice, abet at a lower temperature. The food in my freezer will be a bit warmer than the cold plate. Maybe cycling between 10F and 30F.

Bill

[a64pilot]

Your right, a PH water mix isn’t really a Eutectic mix.
Way over my head definition https://en.m.wikipedia.org/wiki/Eutectic_system
Water and food grade PH simulates if you will a Eutectic mix well enough, I think a water salt mix would be better, but then you get to deal with the corrosive nature of the salt.
However what I was trying to say was I think most Eutectic systems cycle below the freeze point of the mix, it never really even turn to slush.
Not all systems do that of course.

Part of the problem is I want my freezer to be near zero, next guy wants it to be below zero, and the next is fine with 15 degrees. If we all have the same box, we would still need three different mix ratios to melt and refreeze at these different temps.
Then add in you have a much better insulation then I do and your box will stay within 5 degrees of the cold plate temp, but my poorly insulated and bigger box requires the cold plate to be 20 degrees colder than box temp and you end up with having to customize your mixture percentage to actually get your cold plate to even partially phase change.

It can be done of course, just think it would take some tuning if you will to adjust to the different conditions.
Now if one manufacturer made all the components, then of course they could control the variables and could adjust the mix to actually phase change.

I have watched my plates, it’s easy to do, and they seem to remain frozen and never turn to slush, and I think that is common.
It may also be that due to how a TXV throttles compressor output, it’s possible that maybe you don’t want a phase change to occur, the monstrous energy absorbed when a big plate phase changes, may require the compressor to get into a less efficient mode to freeze that plate back down, it may be more efficient for it to run in a lower output, the difference in COP may drive that.
Just theorizing, but I think it’s possible, testing of course would tell the tale.

[SV THIRD DAY]

Originally Posted by a64pilot

However what I was trying to say was I think most Eutectic systems cycle below the freeze point of the mix, it never really even turn to slush.
Not all systems do that of course.

Part of the problem is I want my freezer to be near zero, next guy wants it to be below zero, and the next is fine with 15 degrees. If we all have the same box, we would still need three different mix ratios to melt and refreeze at these different temps.

I can't speak for all Eutectic Systems but ours Freezes Solid and our systems (freezer and refrigerator holding plates) operate below the freezing point of the Eutectic solution.

Regarding the Different Temperatures of the Thermostat Set-points, ALL of the freezer stat set-point will keep the Eutectic solution Frozen. That is why you can't use the same Thermostat and Eutectic solution for a Freezer and Refrigerator. But all of the 1-7 temps on the Freezer Stat will keep the Eutectic solution in our holding plate frozen.

Originally Posted by a64pilot

Now if one manufacturer made all the components, then of course they could control the variables and could adjust the mix to actually phase change..

We do, we make it all in house. But we don't want the phase change. It costs you too much energy to phase change it back...how do I know...remember 50 Years of building Eutectic Hold Over plates....test data my friend.

Originally Posted by a64pilot

I have watched my plates, it’s easy to do, and they seem to remain frozen and never turn to slush, and I think that is common.
It may also be that due to how a TXV throttles compressor output, it’s possible that maybe you don’t want a phase change to occur.

That's how Technautics had been designing Eutectic Holding Plate systems for 50 YEARS....so yours is working perfectly as designed....

[a64pilot]

Originally Posted by SV THIRD DAY

We do, we make it all in house. But we don't want the phase change. It costs you too much energy to phase change it back...how do I know...remember 50 Years of building Eutectic Hold Over plates....test as....

By all of the components I meant the box too, if you could control box size and R value etc, it would make designing a system so much easier, cause it’s requirements are both known and set. You don’t have to have a system that can flex if you will to fit different conditions.
See I think if you can do that, that maybe you could make even a restricted orifice thin plate system efficient. The Engel for instance seems to be pretty efficient, and I doubt the swing compressor is the reason why, and I know it’s not super insulated, cause mine sweats.

[SV THIRD DAY]

[QUOTE=a64pilot;2645311The Engel for instance seems to be pretty efficient, and I doubt the swing compressor is the reason why, and I know it’s not super insulated, cause mine sweats.[/QUOTE]

Bingo...what makes the Engle "efficient" is their small size of Box!
But put a CoolBlue inside such a small box and surprise...we beat the Engle But the truth is...most Cruisers Want More...MORe...MORE Space for their Cold Beer.

[OzePete]

Originally Posted by Richard Kollmann

Pete also talks about the need for soft start modules. Absolutely I do and hopefully by now you have worked out how they function and the benefits or are you still suggesting that the DOL modules are/were without major failure problems? Because if you think the old DOL module type is ok, there are many thousands of peed off users out there who have spent big dollars on replacing those crap things, and who would totally disagree with you!


My reply is there are many thousands of pleasure boat refrigerators that were designed for Danfoss BD compressors and if installed correctly do not have the need for Soft or Hard Start control modules. You can put Band Aids on a weak design moving trouble somewhere else, another bad idea. In the last year I have tested over 100 modules finding at least 40% failures due to reverse voltage spikes and over heated power circuits. As long as designers and installers push the design envelope on a system’s high pressure and compressor temperatures, control modules will fail. If you know of a compressor that can avoid these problems. then you should share that knowledge with all of your readers instead of making asinine statements about things that you don't seem to understand.

Richard, I doubt you understand what 'soft start is. It has nothing to do with 'hard starters you quote, they relate to single phase AC motors!

Oh, and when are you going to acknowledge that Secop Motor driver modules are now SOFT START, and have been for nearly two years! You know, the type of motor driver module that you have been bagging just because I have been presenting them as a far better option than the old DOL modules, but perhaps Secop is wrong too!

So who is making the "asinine statements about things that you don't seem to understand". Read your past posts bagging 'soft start modules for a clue, Richard.

Cheers OzePete