Coil Type Identification; Novationtcoil Cleaning And Maintenance; Repairing Novation Condenser Tube Leaks - Carrier 38AU Installation, Start-Up And Service Instructions Manual

Coil Type Identification

38AU units are available with different coil types. Cleaning
methods differ for each type so identifying the coil type is
important. Unit model number and appearance can identify
the coil type.
NOVATIONt Type —
The new NOVATION Heat Exchanger Technology is an
all- - aluminum construction with louvered serpentine fins
over single- - depth crosstubes. The horizontal crosstubes have
large diameter aluminum headers on each end.
optional coatings are also available.
38AU units use two- - row segmented coils.
Fig. 42 - - NOVATION Heat Exchanger Coil
Model number designation: See Fig. 3 for general unit
model number format. Position 11 indicates the coil type
and coating. Position 11 values of G, K, T and W indicate
NOVATION coil type is on this unit.
Round- - Tube Plate- - Fin (RTPF) Type —
This construction uses a series of small diameter copper
hairpin tubes running horizontally with vertical plate fins.
The plate fins may be aluminum (standard) or copper
(optional). Various optional coatings are also available.
These coils may be one- - row or two- - row.
Model number designation: See Fig. 3 for general unit
model number format. Position 11 indicates the coil type
and coating. Position 11 values of A, B, C, M, N and P
indicate RTPF coil type is on this unit.
NOVATION Coil Cleaning and Maintenance —
To clean the NOVATION condenser coil, chemicals are
NOT to be used; only water is approved as the cleaning
solution. Only clean potable water is authorized for cleaning
NOVATION condensers.
Clean the coil as follows:
1. Turn off unit power.
2. Remove screws holding rear corner posts and top cover
in place. Pivot top cover up 12 to 18 in. (305 to 457
mm) and support with a rigid support. See Fig. 43.
Various
TUBES
FINS
MANIFOLD
MICROCHANNELS
C07273
Fig. 43 - - Pivot and Support Top Cover
3. Carefully remove any foreign objects or debris at-
tached to the coil face or trapped within the mounting
frame and brackets.
4. Using a high pressure water sprayer, purge any soap
or industrial cleaners from hose and/or dilution tank
prior to wetting the coil. Clean condenser face by
spraying the coil core steadily and uniformly from top
to bottom, directing the spray straight into or toward
the coil face. Do not exceed 900 psig or a 45 degree
angle; nozzle must be at least 12 in. (30 cm) from the
coil face. Reduce pressure and use caution to prevent
damage to air centers (fins). Do not fracture the braze
between air centers and refrigerant tubes. Allow water
to drain from the coil core and check for refrigerant
leaks prior to start?up.
5. Replace top cover and rear corner posts.
CAUTION
!
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Chemical cleaning should NOT be used on the
aluminum microchannel (NOVATION) condenser.
Damage to the coil may occur. Only approved
cleaning is recommended.
Repairing NOVATION Condenser Tube Leaks —
RCD offers service repair kit Part Number 50TJ660007 for
repairing tube leaks in the NOVATION coil crosstubes. This
kit includes approved braze materials (aluminum fluxcore
braze rods), a heat shield, a stainless steel brush, replacement
fin segments, adhesive for replacing fin segments, and
instructions specific to the NOVATION aluminum coil. See
EPIC for instruction sheet 99TA526379.
The repair procedure requires the use of MAPP gas and
torch (must be supplied by servicer) instead of conventional
42
C10216