First Co WH / XH Horizontal Double wall - Manual (Page 9)

9
Hinged Doors
Larger units, 7.5 ton and larger, have hinged doors that can be lifted off for
component access. This allows free access for blower or motor assembly
replacement. Enough side clearance is needed to open the doors at
least 80 degrees to remove them.
Use the door width as a simple guide for side clearance.
Blower
Inspect the bearings for wear. They are ball bearing, self-aligning and grease packed. Replace if required. Inspect the thrust
collars for end play and alignment of wheel. Check the blades for accumulations of dirt and clean in order to avoid imbalance
and vibration. Check mounting brackets, base bolts and isolation material.
Motor
Check motor connections to ensure that they are secure and made in accordance with the wiring diagram.
The blower motor should be cleaned annually and if it has oiling ports, it should be oiled with a good grade of SAE 20 oil. Normally
a few drops of oil in each bearing is sufficient.
Coil
Any dust or other contaminants which accumulate on the heat transfer surfaces interferes with the air flow and impairs heat
transfer. The coil must be kept clean by cleaning with low pressure compressed air or flushing / rinsing with water (a detergent
is advisable for greasy surfaces).
For severe conditions the air handlers coils are designed for removal. The coils may be removed one at a time starting with the
last coil in the air stream. Disconnect piping from all coils. Remove drain pan door by loosening the two thumb screws. Next
remove the coil panel door. Supply side coils are removed first by removing 3 screws holding the coil to the return side coil and
pulling the coil straight out. The final coil is removed by removing three screws holding the coil support bracket to the cabinet
and pulling it straight out. When this coil is reinstalled the coil support bracket on the opposite coil end must slide in behind
the cabinet corner post.
WARNING: Coils are heavy. When removing coils from the unit have an appropriate lifting device that can
handle the coil weight. Coil fins and end sheets are sharp and can cause severe personal injury. Failure to
do so will result in personal injury and equipment damage.
Filter
The air filter should be cleaned or replaced every 30 days or more frequently if severe conditions exist. Always replace the filter
with the same type as originally furnished.
Drain Piping
The drain should always be connected or piped to an acceptable disposal point sloped away from the unit. Check the drain line
for restrictions or blockage before summer operation and monthly during the cooling season.
Drain Pan
The drain pan should be clean to allow proper condensate flow. Remove any accumulation of residue from the drain pan and
inspect. To remove the drain pan, disconnect condensate piping at unions if used. Loosen drain pan door thumb screws. Drain
pan and drain pan door can be pulled out of the unit. Drain pan can be cleaned with mild detergent. When drain pan is reinstalled
it must be centered under the coil supports and pushed in completely so the drain pan door can be reinstalled.
Maintenance Updates
A current copy of the Maintenance Program log can be found at www.firstco.com under “Product Information”.
CAUTION: Doors are heavy sheetmetal assemblies. If you are going to lift them off then wear gloves and have
a plan for getting them down from the unit and back. Ensure that no one is standing or working under you in
the event you lose your grip and drop the door.