Drain Connections - Mitsubishi Electric M Series Installation Manual

12. Drain connections

IMPORTANT!
Over-tightening the drain connections could result in drain pan
breakage and failure.
Please follow the following technique for attaching the drain pan
adapter:
1. Apply (2) wraps overlapping of sealing tape
2. Torque the drain pan adapter to 2.5 Nm +/-0.5 [22 in-lb]
The air handler contains ¾" FPT drain connections. When the unit
is used in the vertical position, there is one set. When the unit is
mounted horizontally there is one set. Each set contains a primary
drain and a secondary or auxiliary drain. The primary drain is the
one that is lowest (even with the bottom of the pan). The secondary
drain is at the higher level. They are labeled on the dimensional
drawings above.
-These units operate with a positive pressure at the drain
connections and although a P-trap is not required, it is
recommended to prevent capacity loss. Always follow local
codes and standards
-The trap needs to be installed as close to the unit as possible.
Make sure the top of the trap is below the connection to the drain
pan to allow complete drainage of the pan.
-Slope the drain line a minimum of ¼" per foot.
-Do not reduce the pipe size from ¾", this could cause premature
blockage in the lines
-Do not braze near the plastic drain piping
18
2" Min.
2" Min.
Note:
Horizontal runs must also have an anti-siphon air vent
(standpipe) install ahead of the horizontal run to eliminate air
trapping. Horizontal drain lines must be pitched a minimum ¼" per
foot.
Route the drain lines outside or to an appropriate drain. Drain lines
must be installed so they do not block service access to the front
of the unit. 24" clearance in the front is for routine maintenance or
service.
Note:
Check local codes before connecting the drain line to an
existing drainage system.
Insulate the drain lines where sweating could cause water damage.
Upon completion of installation, it is the responsibility of the
installer to ensure the drain pan(s) captures all condensate, and all
condensate is draining properly and not getting into the ductwork/
system.
Vertical Mounting:
When mounted vertically, the air handler's primary drain connection
is located in the center of the unit. The slightly higher drain to the
left is the secondary drain.
Attach the drain connector and tighten TO THE PROPER TORQUE
SHOWN PREVIOUSLY with sealant and install the drain line.
IMPORTANT!
Over-tightening the drain connection could result in drain pan
breakage and failure.
The secondary connection should be connected to a separate
drainage system. Run the secondary drain so the occupants will be
able to notice water owing through the secondary drain indicating
a blockage in the primary drain. Optional use for the secondary is a
primary drain line over ow switch (provided by others). This device
will shut the cooling operation unit down in the event of a primary
drain line blockage. See wiring section for connecting this device.
Horizontal (Left or Right):
If the unit is installed horizontally, remove the knockout in the front
panel to gain access to the side drain pan connections. Attach the
connector as described above and route drain line. Any vertical
drain pan openings must be covered to eliminate air loss which will
decrease the capacity of the unit.
IMPORTANT!
Over-tightening the drain connection could result in drain pan
breakage and failure.
The secondary connection should be connected to a separate
drainage system. Run the secondary drain so the occupants will be
able to notice water owing through the secondary drain indicating
a blockage in the primary drain. Optional use for the secondary is a
primary drain line over ow switch (provided by others). This device
will shut the cooling operation unit down in the event of a primary
drain line blockage. See wiring section for connecting this device.
2" Min.
Anti-syphon
air vent
Vent T
Drain Trap