Unit Start-Up; Adding Refrigerant For Longer Line Set; Troubleshooting; Test Run - Lennox MLA Series Installation & User's Instructions

Single-zone mini-split system, floor mount console
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Unit Start-Up

IMPORTANT
Units should be energized 24 hours before unit start-up
to prevent compressor damage as a result of slugging.
1. Inspect all factory- and field-installed wiring for loose
connections.
2. Verify that the manifold gauge set is connected.
3. Add additional refrigerant charge if required before
opening valves and while system is still under a
vacuum.
4. Open the liquid and gas line service valves to release
the refrigerant charge contained in outdoor unit into
the system.
5. Replace the stem caps and tighten to the value listed
in "Table 4. Flare Nut Torque Recommendations" on
page 12.
6. Check voltage supply at the outdoor unit terminal strip.
The voltage must be within the range listed on the
unit's nameplate. If not, do not start the equipment
until you have consulted with the power company and
the voltage condition has been corrected.
7. Refer to the included user guide to operate the system
using the provided remote control.
8. Visually check for binding of both indoor and outdoor
fans.

Adding Refrigerant for Longer Line Set

The outdoor unit is factory-charged with refrigerant.
Calculate the additional refrigerant required according to
the diameter and the length of the liquid pipe between the
outdoor unit and indoor unit connections.
Be sure to add the proper amount of additional refrigerant.
Failure to do so may result in reduced performance.
Table 8. Additional Refrigerant Charge
System Size
Pipe Length
(KBtu)
(feet / meters)
12
>25 (7.5)
Amount of Refrigerant
to add
0.161 oz/ft (15g/m)
17

Troubleshooting

See "Error Codes" on page 19 for details on
troubleshooting.

Test Run

Pre-Checks

Only perform test run after you have completed the
following steps:
Electrical Safety Checks – Confirm that the unit's elec-
trical system is safe and operating properly
Refrigerant Leak Checks – Check all flare nut connec-
tions and confirm that the system is not leaking
Confirm that liquid and gas valves are fully open

Procedure

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 following
functions, one at a time:
COOL - Select lowest possible temperature
HEAT - Select highest possible temperature
4. Let each function run for 5 minutes, and perform the
following checks:
Table 9. Test Run Checklist
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
Unit performs HEAT function
properly
Indoor unit louvers rotate
properly
Indoor unit responds to
remote controller
Pass
Fail
Outdoor
Indoor
(2):
(2):

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