mitsubishi start up

[ballvalve]

help needed please

was called out to comission a city multi p200 with 4 indoors.sounds easy,till i tryed to address it.they have to be the most complicated unit to address,,turn switch that way turn switch this way.
any way i have the bc box set for 51 and each indoor set for 101 102 103 104 as this is what i have been told to do.but still no joy.any words of wisdom would be very handy
thanks in advance

[AbsoluteWDJ]

help needed please

was called out to comission a city multi p200 with 4 indoors.sounds easy,till i tryed to address it.they have to be the most complicated unit to address,,turn switch that way turn switch this way.
any way i have the bc box set for 51 and each indoor set for 101 102 103 104 as this is what i have been told to do.but still no joy.any words of wisdom would be very handy
thanks in advance

The outdoor unit should be set to 51 and BC controller to 52. Make sure the port addressing dial (SW14 indoor PCB's) correspond to actual ports on BC controller.

[Thermatech]

The Mnet address logic is very simple & it works like a small network of computers. Each circuit board with an address communicates with other units in the network by sending data on the 30v dc mnet data communications cable.

1/ Indoor units can be set with any address 001 through to 050.
2/ Outdoor units & BC boxes can be set with address 051 through to 100 with the outdoor unit address set at smallest indoor unit address +50 and then the BC address outdoor unit address +1.
3/ Local Mnet remote controllers PAR27MEA must be set to match the indoor unit address 101 through to 150.

Your system is a very small stand alone system so address settings should be as follows.

Indoor unit 001 remote controller 101
indoor unit 002 remote controller 102
Indoor unit 003 remote controller 103
Indoor unit 004 remote controller 104

Outdoor unit 051
BC unit 052

All circuit boards have the 100's digit preset. So for example the indoor unit full address is 001 but you dont have to set the 100's digit as it is already preset on the circuit board, so you just set 0 on the 10's digit rotary switch & 1 on the 1's digit rotary switch.
Every unit in the system has to have a unique address otherwise if 2 units send data into the Mnet network but both are the same address the system reports a duplicate address error.

All indoor units need to be told by the commissioning engineer which port at the BC box the indoor unit is connected to with the refrigeration pipe connection so that when the indoor unit requests heat or cool the correct port at the BC box can supply the refrigerant to the correct indoor unit.

Using this address setting logic you can have up to 50 indoor units controlled from a G50 / AG150 central control using the Mnet data network.

It matters not where the units & remote controllers are actually connected onto the 30v dc Mnet data cable.
So you could have all the PAR27MEA remote controllers together in one location & they could all be daisy chained togther & one wiring link from all 4 & connect to the nearest Mnet terminal which could be for instance at the BC box or the outdoor unit.
The remote controller does not have to be connected with communication cable to the indoor unit which it is controlling but just needs to be connected to the Mnet network & provided the address is correct it will control the appropriate indoor unit or group of indoor units.
In veiw of this you can see that it is possible to save a great deal of time & money because the communication cable installation can be made very simple.

Mitsubishi have been selling City Multi in Europe for at least 18 years & the Mnet addressing logic has always been exactly like this.

Of course some other VRF systems dont have to set the address settings but instead you need direct wiring control cable so that indoor unit only can communicate with its BS box & remote controller to which it is connected with the direct control cable link.
So for example on some other VRV / VRF system if a number of indoor units need to be controlled in a group you have to install a control cable daisy chain from the remote controler to all those indoor units.
But with City Multi you only have to connect the remote controller to one Mnet terminal at any location in the network & provided the address setting is correct it will control the group of units.

The Mitsubishi desiners of City Multi systems deploy a network solution which makes very simple control cable installation but does need addressing set up instead of more complicated & expensive control cable installation.

For the commissioning sheets you need to put your step ladder up to each indoor unit & note the model / serial number & check things like 240v power connected.
It only takes a few seconds to set the 3 rotary dips for the Mnet address & Branch / port address.
That seems alot easier & cost effective compared with installing a seperate 2 core controls cable from every indoor unit back to the BC box in addition to the controls cable daisy chain from the indoor units back to the outdoor unit.

If you want to save some money on the remote controllers you can use the 12v dc remote controllers PAR21MAA option. In this case there is no address setting for the remote controller but like other VRV / VRF systems the remote controller has to have direct connection to the indoor unit or daisy chain to the group of indoor units & then you spend the money on the extra control cable + cable ties + labour. So most contractors tend to use the 30v dc Mnet remote controllers PAR27MEA as it saves alot on installation costs.

After you have done one or two systems & understand the Mnet address setting logic its becomes second nature & you can do it on auto pilot.
Then you too can be a happy dip switch flicker

[ballvalve]

thanks for the info thermatech.ill try that on monday morn.i had the indoors set for 101 102 etc and remotes at 01 02 etc.i take it that 0 on the remote is 100.iwas getting a 52-7102-66 error code on remote with bc in the top right hand flashing.any other vrf system ive done has never been this hard to get my head around,but as you said its becomes second nature when you get your head around it.

thanks again for the time spent spelling it out

[r0ss]

Remember when doing you're addressing dial switches on the units you will only need to turn the SW11 (unit address) and the SW14 (BC port address)

Only when you have more than 9 units will you need to turn the SW12 dial

[Crypton]

Some answer Thermatech.well explained.

[ballvalve]

Which do you power up first when addressing

[Thermatech]

All the time the outdoor unit has 415v power it is generating 30v dc Mnet communication to the BC, all indoor units & remote controllers.

So really it helps at the commissioning stage to make all the address settings first & then turn on power to outdoor unit.

But you also want to have power on to outdoor unit for crank case heater so that it will be ready to run.

So what some engineers do is leave the Mnet cable disconnected at the outdoor unit & turn 415v power on for the CCH. The outdoor unit just reports a fault because it cannot see any indoor units.
Then you can go arround all the indoor units & set address settings, turn on 240v power at the spur, record model / serial number ect.
Make sure 240v power is also on to the BC box.
Then connect the Mnet communinations cable at the outdoor unit with a power reset.
The outdoor unit will carry out electronic hand shake will all units it finds in the system & will be ready for a test run.

[ballvalve]

thanks thermatech
usally there is an auto address button you just press after setting up your indoor units.
so its outdoor unit-51
bc box- 52
indoor-101 remote-01
indoor-102 remote-02
and so on

[Thermatech]

And if you have any problem the Mitsubishi Electric technical support enginners in Ireland will be able to help with telephone support.

[Robocool]

So when you set Sw14 I assume port one is setting one and for eg port 12 will be setting c etc

[Robocool]

So does port one = setting one on SW14 and port 12 = setting C etc

[Thermatech]

The largest BC box has 16 ports.
It is important to tell the indoor unit which port at the BC box it is connected to with refrigeration pipework so that the indoor unit gets correct heating refrigerant flow or cooling refrigerant flow when the indoor unit requests heating or cooling from the BC box.
It is the responsibilty of the commissioning engineer to program this BC port connection information into each indoor unit using the indoor unit SW14 rotary dip switch.
The port address setting rotary dip SW14 at the indoor unit has 16 possitions.
For example
Sw14 = 1 for indoor unit refrigeration pipe connected at BC box port 1
Sw14 = A for indoor unit refrigeration pipe connected at BC box port 10
SW14 = F for indoor unit refrigeration pipe connected to BC box port 15
SW14 = 0 for indoor unit refrigeration pipe connected to BC box port 16