McQuay IM 672-7
35
Maintenance
Winterizing Water Coils
Coils can freeze due to air stratification or failure of outdoor
air dampers and/or preheat controls. Drain all coils as
thoroughly as possible and then treat in the following manner.
•
Fill each coil independently with an antifreeze solution
using a small circulating pump and again thoroughly drain.
•
Check freezing point of antifreeze before proceeding to next
coil. Due to a small amount of water always remaining in
each coil, there is a diluting effect. The small amount of
antifreeze solution remaining in the coil must always be
sufficient enough to prevent freeze-up.
Note:
Carefully read instructions for mixing antifreeze solution
used. Some products have a higher freezing point in
their natural state when mixed with water.
McQuay
International is not responsible for the freezing of
coils.
Removing and Replacing
Components
Removing a Side or Top Panel
1
Remove the flat head fasteners located along the sides of
the panel.
2
Once all fasteners are removed, lift off the panel.
Removing a Frame Channel
Frame channels that run the length of the unit along the top can
be removed to allow access to both the side and top of the unit.
1
First remove any adjoining side and top panel(s).
2
Once the side panel is off, remove the flat head fasteners in
the corner of the frame channels.
3
Pull the frame channel out the side.
4
If any top panel fastens into the frame channel (when the
frame channel is 24" or wider in direction of air flow),
remove the fasteners in the top panel before pulling out the
channel.
Removing the Fan Section
The fan shaft, motor, and any drive components can be
removed and replaced through the access door opening. If
required, the side panel can be removed for additional access.
If fan replacement is required, the entire fan assembly can be
pulled out the side of the cabinet. The fan assembly includes
the fan housing, the bearing support, and the fan base.
1
Remove the side panels and any intermediate supports
(follow instructions for side panel removal).
2
Once the panels and any intermediate supports are
removed, disconnect the neoprene bulk head seal that is
attached to the fan discharge.
3
Remove the four discharge angles that hold the neoprene
canvas in place around the discharge opening.
4
Disconnect the fan sled from each of the corner mounts and
pull the entire assembly out the side of the unit.
5
After the fan sled is out, loosen the fan bearings and pull
out the shaft.
6
Disconnect the fan housing from the fan sled, and bearing
support by removing the attaching bolts.
7
Replace the new fan, reconnect the shaft and bearings and
put the fan assembly in the cabinet.
8
Replace panels and fasteners.
Removing and Replacing the Coil
The coil can be removed by the side, top, or a combination of
both. The size and configuration of the coil affects how the
coil can be removed. Single banks of coil are fastened only on
the connection side of the unit. Stacked and staggered coils are
fastened on both ends of the coil. See the instructions below
for details to remove each coil type.
Before removing the coil, disconnect all piping. The
instructions below assume the coil is mounted in a
sectionalized coil section where the frame channel can be
removed without affecting other components. If the coil
section is unitized with other components, removing the top
frame channel requires removing additional panels.
Removing Single Coils
Note:
Single coils are bolted to the unit on the connection end.
The connection end is held in place with a clamp
.
1
Disconnect all piping and remove the brass plugs for the
vents and drains located in the connections.
2
Remove all screws and remove the access panel.
3
Remove the screws holding the coil in place.
4
Lift and pull the coil out the side.
WARNING
Mold can cause personal injury. Clean drain pan regularly so
mold does not develop.
AVERTISSEMENT
La moisissure présente un danger respiratoire. Pour éviter la
moisissure, nettoyer régulièrement le bassin de drainage.
WARNING
Before removing any component, lock out and tag out all
power to the unit. Fans and belts can cause severe personal
injury or death.
AVERTISSEMENT
Avant d’enlever toute composante, couper et indiquer que
l’alimentation électrique à l’unité est coupée. Les ventilateurs
et les courroies peuvent entraîner des blessures personelles
graves ou même la mort.
