mitsubishi electric centrall controller G-50A

[sork]

hi guys
working on multi city one unit does not operate, temp is 35c
on the disply i have on cool fan at 4
set temp at 19c no error code , other units all ok
select group set in cooling use arrow mon blink then i press enter , address replies,
press the swith to operate.
how do i get tit working?
secondly the setting at the function area is blinking, is that normal?:off topic:

[Thermatech]

For normal control of individual groups you do not need to make any setting at the bottom of the screen like
mon col m mr
Please RTFM the operation manual & you will see.
For instance
if you use the <> keys to make col flash then you can make a setting which will change all units together collectively.

For normal adjustments to operating settings
Just scroll through to the group you want to switch on & press the on button mode button fan speed button & set temp up/down & make the settings you want.
If the unit has a local controller then you will see the change you have made at the G50 instantly at the local controller.
If the indoor unit does not operate then you will need to invesigate further.

[sork]

hi thermatech thanx brother means a lot to me, i have not installed the unit, so great of you for any info.
i heard the fan noise in the indoor unit in question but what ever poss i tried, you recon the controller has a password?if not what do you think my next step is?
i thought i may look at the indoor unit filter or voltage or maybe no gas is entering the unit.
what next???????????

[Thermatech]

Use the engineers mode at the G50 to find out what the Mnet address of the indoor unit for that group is.

When you know what the indoor unit Mnet address is then you can go & check that indoor unit for correct Mnet & Branch address if the system is R2 heat recovery.

Double check you have control of the right indoor unit by switching fan on / off at the G50 with all other units off
then you know for sure you have the right indoor unit.

If the system is R2 the indoor unit will be connected to a port at the BC box.
Check what port number the refrigeration pipes are connected to for the indoor unit to BC box
then
check the branch address setting at the indoor unit to make sure it is set for the right branch which the refrigeration pipe is connected to at the BC box.

Common mistake at commissioning to get branch address settings wrong.

Then put the indoor unit to Test Cool at the G50 & see what the indoor unit does.
If no cooling investigate correct solenoid valve opening for the port at the BC box.
If thats ok then check correct opening of indoor unit LEV valve.
If thats ok then you might have blocked strainer.

You can also try in Test Heat mode
If the solenoid valve for heat opens at the BC box you should get the indoor unit coil full of hot gas for a few mins but if LEV locked shut or problem with liquid line strainer blockage then there will be no flow of hot gas through the coil & it will gradually cool down back to room temp as the hot gas condenses to liquid.

On new systems
Sometimes there has been incorrect set up of the indoor unit in the groups at the G50.
Sometimes incorrect branch address setting at the indoor unit.
Sometimes sparks disturbed LEV wiring connection at indoor unit circuit board when making power & control wiring connections.

On older systems
Sometimes the BC port solenoid coils fail which prevents flow of refrigerant to the indoor unit connected to that port.
Sometimes LEV valve fails locked shut.

You just need to check the basics first & then work through a logical trouble shoot procedure to locate the problem.

Make sure you go to site with the correct service manual because without that you will be going no place fast.

[sork]

hi thermatech

thank you so much mate