Mitsi cassette controller question.

[Chunk]

Hi,I have 7 cassettes in offices in one of my supermarkets,all of which are single splits and have their own seperate wired wall mounted controllers.

These controllers allow you to change the temp and adjust fan speeds as normal,but when you try to switch off using the power button,they flash "centrally controlled"and wont turn off.I have to switch off in main electrical panel for shop services.

My questions: Can this "centrally controlled" bit be bypassed on the controller ie;changing a setting? or bitswitch on the unit?
Or does something need to be rewired?

There 4 different models of cassette,but they have the same standard controller,i dont know if you will need a model number to answer:Dbut can be got if needed.

Cheers

[The Viking]

I might be wrong here...

My suspicion is that they (the indoor units) got an interface board fitted that interlink them to a central time-switch.

If you disconnect the interface from the main PCB, they will become individually controlled.

[Chunk]

I might be wrong here...

My suspicion is that they (the indoor units) got an interface board fitted that interlink them to a central time-switch.

If you disconnect the interface from the main PCB, they will become individually controlled.

Hi Viking

I think they are somehow linked in with building services(trend)system,but i looked through the schematics briefly and it drops the feed through a relay in a control panel to switch them off at night or if there is a fire alarm.

I just would have thought you should still be able to switch off on remote.

I cannot get access to the "Trend" system but i cant see any other cables going to cassettes.I`ll have a look for that interface board,they might have hidden it so i cant see it.Cheers.:D

[1torr]

Sounds like there are 3 wire adapters fitted to each system. 3 wire colours are brown, red, orange from memory. These are fitted to allow bms on/off control or fire shutdown. Hope this helps. Kev.

[frank]

Mitsi's connect to the BMS via the remote controller.

Take the controller off the backing panel and you will see a small 3 wire connection with a small white plug. Unplug this and then you disable the 'centralised control' during servicing work (or permanently).

[Chunk]

Thanks guys.

I take it 1torr is talking the same thing,so i will whip it off tomorrow.

It`s the girls in a couple of the offices moaning,one says the a/c gives her a headache,and the other office moan that it`s causing them to get wrinkles!!

I would normally have told them to stop wasting my time(these units have been there for 8 years)but who can refuse a bunch of crazy old ladies?:p

[The Viking]

It`s the girls in a couple of the offices moaning,one says the a/c gives her a headache,and the other office moan that it`s causing them to get wrinkles!!



Oh that makes me smile!

Today I were called out to a system we "commissioned" recently because of a fault code on a controller that controlled 3 cassette indoor units.
As I start to look at the remote, the lady that sits directly below one of the cassettes ask if I can do something about the unit causing her eyes to hurt...

Well, the fault was that the "commissioning" engineer hadn't told the controller that it controlled more than one unit.

You guessed it, the unit she complained about had never run:eek:

[Thermatech]

If the units are 8 years old then the 3 wire adapter might be connected at the remote control as it was on the really old R22 Mr Slim systems.
Just unplug to regain full on/off control.
About that time Mitsubishi changed the design & the wiring adapter was connected to the indoor circuit board for remote on/off control.

BTW you may need to do a power reset at the unit.

[Chunk]

I`ve got 2 Large a/c package units that were installed last year,i got a call saying the bakery in the store was too warm and could i have a look.

There was no air coming from the vents,but the units were running ok.Looked above false ceiling,there was not any ductwork,just a hole.Next to the hole was the extract fan sucking the cold air straight back out.

[Chunk]

The "crazy old ladies" said thanks.

The wires were on the controller and nice and easy to remove.Power reset.All is good.:D

Thanks chaps.

[Thermatech]

Thank goodness for the female office staff. Without there regular complaints about the a/c we would not get half the callouts to imagined problems.
You only have to drop the smallest hint of a comment & they will be calling you back to site for the next 18 months garanteed.

[Greengrocer]

Thank goodness for the female office staff. Without there regular complaints about the a/c we would not get half the callouts to imagined problems.
You only have to drop the smallest hint of a comment & they will be calling you back to site for the next 18 months garanteed.

Ladies bloew hot & cold. Put a dummy t'stat on the wall and let them play with it. Put the controller in the cupboard and all will will be well.

[sinewave]

Ladies bloew hot & cold. Put a dummy t'stat on the wall and let them play with it. Put the controller in the cupboard and all will will be well.



Yer not wrong there! :cool:

[Chunk]

I dont do as much a/c as you guys,but i can safely say that given the choice,i would rather work with the older ladies as you can have a bit of a banter with them.The younger ones just think you are a perv.

Just my own opinion.;)

[Greengrocer]

I dont do as much a/c as you guys,but i can safely say that given the choice,i would rather work with the older ladies as you can have a bit of a banter with them.The younger ones just think you are a perv.

Just my own opinion.;)

If the younger ones think you are a perv at 33 then I've got no chance.

[frank]

I usually start off by telling them I AM a perv :D

Then I proceed to set the units in TEST mode, lower the set point and await for their little 'in blouse' thermometers to come out :D:o:cool::confused::D:D

[Contactor]

3 lingerie shops in london, no old ladies. it's a fine art and i've mastered it.