Winter Shutdown; Coil Removal - Carrier AERO 39MN Installation, Start-Up And Service Instructions Manual

7. Allow the coil to dry thoroughly before placing the sys-
tem back into operation. A clean dry cloth may be used
to wipe down the interior panels before placing the unit
in operation.
8. Straighten any coil fins that may have been bent or dam-
aged during the cleaning process with a fin rake.
9. Replace all panels and parts that may have been re-
moved prior to cleaning and restore electrical power to
the unit.
10. Use caution to assure that no contaminated materials
contact other areas of the unit or building. Properly dis-
pose of any polluted materials and cleaning fluids.
It is recommended that auxiliary
Winter Shutdown —
drain piping be added to coil piping if yearly winterizing of
coils is anticipated. This auxiliary piping should be located at
the highest and lowest point on the respective header connec-
tion for each coil.
ANTIFREEZE METHODS OF COIL PROTECTION
1. Close coil water supply and return valves.
2. Drain coil as follows:
Method I — 'Break' flange of coupling at each header
location. Separate flange or coupling connection to fa-
cilitate coil draining.
Method II — Open both valves to auxiliary drain piping.
3. After coil is drained, Method I, connect line with a ser-
vice valve and union from upper nozzle to an antifreeze
reservoir. Connect a self-priming reversible pump be-
tween the low header connection and the reservoir.
Method II, make connection to auxiliary drain valves.
4. Fill reservoir with any inhibited antifreeze acceptable to
code and underwriter authority.
5. Open service valve and circulate solution for 15 min-
utes; then check its strength.
6. If solution is too weak, add more antifreeze until desired
strength is reached, then circulate solution through coil
for 15 minutes or until concentration is satisfactory.
7. Remove upper line from reservoir to reversible pump.
Drain coil to reservoir and then close service valve.
8. Break union and remove reservoir and its lines.
9. Leave coil flanges or coupling open and auxiliary drain
valves open until spring.
AIR-DRYING METHOD OF COIL PROTECTION (Unit
and coil must be level for this method.)
1. Close coil water supply and return main valves.
2. Drain coil as described in procedures for Antifreeze
Methods of Coil Protection, preceding.
3. Connect air supply or air blower to inlet header connec-
tion and close its drain connection.
4. Circulate air and check for air-dryness by holding mirror
in front of open vent in outlet header drain connection.
Mirror will fog if water is still present.
5. Allow coil to stand for a few minutes; repeat Step 4 until
coil is dry.

Coil Removal

NOTE: To reinstall coils, refer to Coil Installation section on
page 78.
REMOVAL OF SINGLE HEIGHT COILS (sizes 03-36) —
The coils in horizontal coil sections must be removed from
either side of the unit. Once the external panels are removed
from the unit, the horizontal upper coil section frame members
are easily removable from the framework, to allow hoisting the
coil up and out of the unit.
NOTE: Refer to Table 14 (Dry Coil Weights) on page 33
before attempting to remove a coil from the unit.
1. Lock open and tag all power supplies to unit fan motor
and electric heaters if present.
2. Remove service panel/coil connection panel and the up-
stream service panel and set aside in a safe place.
3. a. On horizontal coil sections without another unit sec-
tion stacked on top, remove the flat corner plug
from each end piece of the top rail.
b. Extract the Torx T25 screw visible within the
exposed cavity. (Do not mix these screws with
others; they are specific for this location. Set screws
aside for reinstallation of top rail.)
c. Remove the top rail by pulling out at a 45-degree
angle. Set top rail aside.
IMPORTANT: Properly support the coil to assure its
stability before continuing with this procedure.
4. Remove the fastening screws from the upstream perime-
ter face of the coil that attach the coil to the coil baffles.
This may require reaching through an opened damper
assembly, reaching through a filter track after filters are
removed, or removing a coil immediately upstream.
Do not handle the coil by the headers or connection
nipples, as irreparable damage might occur that is NOT
covered by warranty. Protect the finned surface from
damage during all handling and shipping.
5. Slip the foam sealing sleeves off the connection nipples
before removing the coil and set the sleeves aside.
6. The coil may now be hoisted out through the top open-
ing or carefully slid out either side of the cabinet. Sec-
tions where the top frame rail cannot be removed may
require slightly tipping of the coil from the vertical posi-
tion, to clear the upper frame rail and seal.
REMOVAL OF STACKED COILS (sizes 40 to 110) — The
coils in horizontal coil sections must be removed from either
side of the unit. Once the external panels are removed from the
unit, the horizontal upper coil section frame members are easily
removable from the framework, to allow hoisting the coil up and
out of the unit.
1. Lock open, and tag all power supplies to unit fan motor
and electric heaters if present.
2. a. Remove service panel/coil connection panel and the
upstream service panel and set aside in a safe place.
b. Remove the top rail by pulling out at a 45-degree
angle. Set top rail aside.
3. a. On horizontal coil sections without another unit sec-
tion stacked on top, remove the flat corner plug from
each end piece of the top rail.
b. Extract the Torx T25 screw visible within the
exposed cavity. (Do not mix these screws with
others; they are specific for this location. Set screws
aside for reinstallation of top rail.)
c. Remove the top rail by pulling out at a 45-degree
angle. Set top rail aside.
IMPORTANT: Properly support the coil to assure its
stability before continuing with this procedure.
132
CAUTION