I am trying to find the installation / operating manual for my Lossnay MVHR unit model KAR-50RSDC I have the manual already for the LGH-50RSDC which seems easy to find and download, but it is different, with a different type of controller PCB.

 

The issue I am having is I cannot manually select summer bypass mode. My unit has two inputs called "heat" and "cool" (which the connection diagram says refer to bypass condition select) and it does not matter which I select, the bypass mode does not turn on.

 

I have just finished the ducting and giving the unit a basic operational check and frustrated I can't operate the bypass mode.

 

Anyone have the manual for the KAR unit or have one working please?

 

Does it have a TM2 and TM3 connector on the right of the board ..?

This is my controller pcb

 

the TM2 and TM3 connectors are at the bottom of the board and have a slightly different function to the LGH version.

Also m board has only one DIP switch with different functions to the LGH version.

 

Well I have not found the manual, but I have been doing some experimenting, which might help others with this version of the Lossnay mvhr units:

 

The unmarked right hand terminal of TM3 activates the summer bypass mode.

 

The DIP switch has different functions to that described in the LGH version manual.  So far I have discovered SW1 is the same test mode.and SW5-8 do the same fan speed fine tuning that Dip Switch bank 2 does on the LGH version.  Not yet worked out what switches 2-4 do.

 

I also found this table about the unit on a website where someone was advertising one. This information is not in the manual so worth knowing.

 

Ventilation mode                                                          Lossnay                                                         Bypass

Fan speed                                                  1             2            3           4                               1            2             3          4

Power Consumption   W                             225         125          57         19                          228       126         57        19

Air volume               m3/h                           468          360       252        144                         468       360       252      144

                                 l/s                            130          100         70          40                          130       100         70        40

Ext static pressure   Pa                            124            73         36          12                          124         73          36        12

Heat exchange efficiency       %                 75.5          79.5       84          88

Enthalpy exchange      Heating     %           68           72.5       77.5      82  

efficiency                     Cooling     %          65           70          75          81  

Sound Level                        dB                  36          33.5       29           23                            37       34.5         30       24

 

(sorry about the poor formatting)

 

I will have to investigate what these heating and cooling modes are all about and what that means in that table?