View Full Version : Mc Quay MDS multi system

26-02-2011, 10:11 AM
has anyone had expierence addressing MDS series A Unit with multiple indoor units. I have installed a MDS060A with Five indoor evaps, but the outdoor unit only turns on with the evap that has the 0 address.
The other evaporators that has adresses of 1,2,3 & 4. would not turn on the outdoor unit.

Any help


26-02-2011, 10:32 AM
Try address the evap units 1,2,3,4,5 .
It's possible setting 0 is a default adress for a stand alone unit.If so the software may not search for multiple connected units.
S1 number 6 on the outdoor board should be on ,to tell the outdoor that there are 5 units connected.check page 99 &103 of attached doc.

28-02-2011, 09:00 AM
Thanks Stufus for your response.
Iwill try your suggestion and let you know the result.However page 103 of the manual is refering to the series B. The PCB on the series A does not have S1, S2 & S3 but instead J1 & J2. (page100)

01-03-2011, 10:52 PM
hi Stu

I have tried your suggestion but it did not work, however thanks .
The installation manual does not tells how to fully address the system. thae series A of the MDS has password protection which only the is given from the sales ageny.
i contacted the local agency and the told me how to address the outdoor unit.

job sucessful.
Thanks again


02-03-2011, 07:08 PM
All's well that ends well !!

03-03-2011, 10:17 AM
Hi All,

What puzzles me is why Mc Quay did not supply the programme instruction in the Installation guide for the MDS Series A.
Seems as though that the want only their technicians to do the job. There are other parameters that can be changed but information is limited. I have'nt work on the Series B, but from the installation guide it seems pretty straight foward because there are switches to set the number of indoor units.

Any suggestions


04-03-2011, 04:16 PM
This is an ongoing issue with many Manufacturers.
At the outset of introducing new machinery the onus is on getting it out the door and into the market.
They will supply it to anyone who will pay for it,the problem arises later when the untrained person installing/commissioning the system decides that since they have been supplied with a list of code variations for parameter changes the HAVE to play around with them knowing they don't fully understand them.
This causes a lot of unwanted nuisance calls to the manufacturer about set up issues.
So they tend to only supply some of the core information to non affiliated people, reducing the call backs .
With the rapid progression of electronic software in air conditioning this is a good thing.
Bottom line if you don't understand it don't f^ck about with it !(not directed at you by the way)
By using password protection they are trying to protect their brand image

31-03-2011, 06:39 PM
Hello Guys,

where are you from?

We have installed many MDS system in the Caribbean and if you need help. Let us know.