14
McQuay IM 777-7
Mechanical Installation
Water Heating Coils
•
Water supply and water return connections extend through
the end panel of the coil section. All connections are labeled
on the end panel.
•
Water supply and water return connections are male NPT
iron pipe.
•
When installing couplings, do not apply undue stress to the
connection extending through unit panel. Use a backup pipe
wrench to avoid breaking the weld between the coil
connection and header.
•
Follow recommendations of the control manufacturer
regarding types, sizes, and installation of controls.
•
Do not use hot water coils with entering air below 40°F.
•
If fresh air and return air are to be heated by a hot water coil,
carefully design the system to provide thorough mixing
before air enters the coil.
•
To prepare coils for winter operation, see
Winterizing Water
Coils‚ page 32
.
Drain Pan Traps
Run drain lines and traps full size from the drain pan
connection. Install drain pan trap to allow condensate to drain
freely. On both blow-through and draw-through units, the trap
depth and the distance between the trap outlet and the drain
pan outlet must be twice the static pressure in the drain pan
section under normal operation so the trap remains sealed
(
Figure 22
).
Figure 22: Allow Adequate Distance Between Trap Outlet
and Drain Pan Outlet
Note:
The door panels on some applications have a close
clearance over the drain pipes. Extend the drain fitting
with a coupling if necessary for door clearance
(
Figure 23
).
Note:
Use material that can withstand freezing temperatures
for outdoor drain traps.
Note:
Drain traps that dry out can allow cold air to seep into the
equipment.
Figure 23: Extend Drain Fitting for Door Clearance
CAUTION
Improper installation, use, or maintenance of water heating
coils can cause equipment damage. Read and follow
instructions carefully.
ATTENTION
Si l’installation, l’utilisation ou l’entretien des serpentins
de chauffage à eau sont inadéquats, ceci endommagera
l’équipement.
Lire et suivre attentivement les instructions.
Pressure (P)
at the drain pan
2P
2P
C l e a r a n c e
D r a i n
