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View Full Version : Converting a Mitsi inverter to a water heater. Help please







beatnik
28-09-2012, 11:31 AM
Hi there. I have been given a Mitsubishi MUZ-FB35VA outdoor unit to play with, intending to make a water heater for a spa pool. I didnt get the indoor unit and here lies the problem. Plug the outdoor in and there is no signal to turn on the compressor. How do you bypass the control side of the circuit board so that when the unit is turned on the compressor just goes, along with the fan. Everything else is redundant or can be worked around. The reason I have this outdoor unit is because 1) its free 2) it 410a. Inverter complicates the system somewhat but there must be a way to get the compressor going. If anyone could help that would be great.

al
28-09-2012, 01:24 PM
Easiest is to but a ducted indoor that matches this outdoor, pull the indoor board and sensors and away you go.

al

stufus
28-09-2012, 03:34 PM
You can get a control gear pack of mitsubishi which is effectivly the indoor unit electrics in a box,usually used for dx ahu's and such.
1/4 the price of the indoor unit.
Cheers
Stu

Greek_engineer
28-09-2012, 08:09 PM
is there any way to make an inverter unit work seperately?without having the indoor or outdoor unit..

stufus
28-09-2012, 08:49 PM
I'm sure there is , but why waste the time trying to second guess something that alot of R&D has been put into to ensure it does what it was designed to do.
If you can match the control logic it can be done.
But in my opinion its easier to go with their gear.
Cheers
Stu

install monkey
28-09-2012, 09:03 PM
Turn off power supply of indoor and outdoor unit, and disconnect
the connector CN781 in the outdoor electronic control P.C.
board.
3 minutes after turning ON the power supply, start EMERGENCY
OPERATION in HEAT mode.
based on a muz fd35va- uk version

install monkey
28-09-2012, 09:19 PM
http://www.mediafire.com/view/?e4kaesu1hs7z5vz
check the back pages refering to pcb inputs
hopefully the safety devices will still be operational

stufus
28-09-2012, 10:58 PM
He doesn't have an indoor unit to turn off
Cheers
Stu

beatnik
29-09-2012, 01:55 AM
Yeah getting an indoor unit and using the circuitry would be the easiest way but I dont have one. I really would rather have a fixed speed r410a outdoor but unfortuatley this is what I was given. Thanks Monkey for the manual. Connected 240v to LD70 and LD66 hoping this would bypass the controls but still just waits for instructions. Interesting to know that if 240v is connected to go through L61 transformer it blink errors 6 times - "Abnormality of serial signal" but if connected after, its lighted continuously - "Normal". Seems strange.

beatnik
01-10-2012, 10:43 AM
On a side question, could an inverter compressor be connected to a wind turbine? I have seen threads regarding this but most suggestions are directly driven like a car ac but could you use a turbine to produce 3 phase ac currant and connect that to an inverter compressor? Being variable speed this could still produce heat in slow wind speeds. Just a thought.