Indoor Unit Connection Points For Centralized Controller; Dry Mode Operation - Indoor Units; Procedure; Dry Mode Operation Sequence - Lennox MCA Series Service Manual

7.2. Indoor Unit Connection Points for
Centralized Controller
Mini-split indoor units can be connected to a centralized
controller (e.g. Lennox VRF Manager - LVM or Trane Tracer)
or a BACnet or LonWorks gateway using the XYE terminals
on the indoor unit main board.
Figure 15. Indoor Unit Connection Points
(Typical Wiring Diagram)
Figure 16. Typical Indoor Unit Connection Points
7.3.

Dry Mode Operation - Indoor Units

7.3.1.

Procedure

1. Press the MODE button to select DRY mode.
2. P ress the UP/ DOWN button to select the desired
temperature. The temperature setting range is from 62°F
to 86°F in one degree increments.
NOTE:
The blower is preset at a low speed and cannot be
changed therefore it will get cold and most likely
will over shoot the temperature setting by 6-10
degrees depending on the room size or other
various factors. Also the Follow Me mode does
not operate in this mode. The Follow Me mode is
only available when a return air sensor is utilized.
Typically in most cases the Follow Me mode will
not be sufficient to remove excessive humidity.
NOTE: In addition, the outdoor units do not have a
humidistat installed therefore they are unable to
determine humidity levels. This product is not
recommend as a main source for dehumidification.
Note, this well over shoot the temperature by 6-8
degrees below what was set for dry mode.
NOTE: Using this mode will over shoot the temp by 6-8
degrees below what was set for dry mode.
(E)
X Y
Y/G
To CCM
Comm.Bus
7.3.2.

Dry Mode Operation Sequence

When in dry mode operation the unit is actually in cooling
mode with a low speed blower operation. The compressor
will stop when the room temperature is two degrees Celsius
lower than the temperature setting.
However there is a temperature compensation for cooling
mode that is two degrees Celsius. So the unit will stop when
the temperature is four degrees Celsius lower than the room
temperature settings.
NOTE:
Four degrees Celsius is equivalent to 8°F
difference.
7.4.

Test Run - Indoor Units

Only perform test run after you have completed the following
steps:
• Electrical Safety Checks – Confirm that the unit's
electrical system is safe and operating properly
• Gas Leak Checks – Check all flare nut connections and
confirm that the system is not leaking
• Confirm that gas and liquid (high and low pressure)
valves are fully open.
7.4.1.

Test Run Instructions

You should perform the Test Run for at least 30 minutes.
1. Connect power to the unit.
2. Press the ON/OFF button on the remote controller to turn
it on.
3. Press the mode button to scroll through the functions,
one at a time:
4. Let each function run for five minutes, and perform the
following checks:
7.4.2.

Before Test Run

Table 3.
Checks
No electrical leakage
Unit is properly grounded
All electrical terminals
properly covered
Indoor and outdoor units
are solidly installed
All pipe connection points
do not leak
Water drains properly from
drain hose
All piping is properly
insulated
Unit performs COOL
function properly
Indoor unit louvers rotate
properly
Indoor unit responds to
remote controller
14
Test Run Checklist
Pass Fail