mini split unit control wire doubt

[Ricardo Pimenta]

Good day,

I have a brandless conventional air conditioner condenser unit connected to a titanium coil in tube to cool saltwater and I would like to change the condenser to a new unit with a better performance maybe a Mitsubishi unit.

The condenser I have installed only receives power directly from my digital thermostat when needed, the problem is that when I was searching for a new condenser I have checked that all of them need 2 cables, one to power supply with 3 cores and the other with 2 cores indentified like control wire that in normal conditions it is connected to the indoor unit.

What I would like to know is if there is any way to connect the outdoor unit under my system without the indoor unit?


Thank you

Ricardo Pimenta

[charlie patt]

use a standard condensor unit maybee and not a ac unit for fuel efficientcy use one of the new danfoss if available wit fan speed control you can then send a standard signal to control ta charlie

[Ricardo Pimenta]

Thank you very much for you suggestion, I know that I could install a typical condensing unit from danfoss (although I do not know witch) because I am not familiar with those and are so many models to choose from.

But I already have talked with some people that are using conventional air conditioner condensers to the same type of application where I intended to use this one, and it seems that they are very satisfied with them.

The only problem I am facing now is don't know how to bypass the PCB from the outdoor unit.


Thank you

Ricardo Pimenta

[paul_h]

Well it's pretty hard to find a name brand conventional (fixed speed compressor) a/c outdoor unit these days, most of them are inverters.
But if you do find a conventional unit (fixed speed compressor), it wouldn't be hard to find one without any outdoor PCB, as all an outdoor unit for conventional needs is defrost and fan speed control, which you could completely remove as you don't need heating.

Bottom line though, using an a/c condensing unit was just the "simpler" way for people using real cheap a/c condensing units.
If you are looking for quality, using a/c condenser is just making it harder for you, lots of hassle finding a conventional fixed speed good quality unit these days, lots of rewiring required by you (fitting a contactor or relays, and safety switches).

I second the idea of getting a proper refrig condensing unit instead. Working out which one to get from danfoss or LU hermatique or any other specialist isn;t any more complicated than finding and then gutting an a/c condenser unit.

[charlie patt]

what is the availability of units where you are? iis it running costs or initial costs that you wish to reduce the last time i say a split without a pcb was at a car boot sale along time ago but its depends on availability where you are

[Ricardo Pimenta]

By the answer I receive until now I am starting to think that it is not possible to used one of these air conditioner condensers without the control wire connection.

I think that generally air con compressor are resistant more silent than refrigeration condensers and cheapest, that’s the main reason that lead me to try using one of those units.

The people I’ve spoken have air con units working with coils like the one I intended to install for more then 10 years without any problem, but they have the old units without that defrost control and don’t need to do any adaptation or modification to the unit, just connect and correct the refrigerant.


Thank you