Dometic 57908.321 Installation Instructions Manual page 8

A. Dometic Corporation recommends the basic configuration shown on page 8 for installing this air conditioner/heat pump sys-
tem. We have found through testing that this configuration works best in most applications of this air conditioner/heat pump
system. It is the responsibility of the Installer of this system to review each RV floor plan and determine the following:
1. Duct size
2. Duct layout
3 Register size
4. Register location
5. Thermostat location
These items must be determined in conjunction with the Air Distribution System and Sizing and Design Requirements
listed in the chart on page 6.
Important:
Alternate configurations and methods may be used which still allow the air conditioner/heat pump to
operate properly; however, these alternate configurations and methods must be approved by the Dometic Corpora-
tion in writing. The following instructions are based upon the use of Dometic 3105007.XXX Return Air kits, 3105935.
XXX Quick Cool kits, or 3308120.XXX genesis Air Filtration System. The 3109226.XXX and 3109407.XXX Comfort
Control Center kits have the mounting bolts supplied for use with these kits.
B. ROOF AND CEILINg OPENINg PREPARATION
1. A 14-1/4" x 14-1/4" (±1/8") opening must be cut through the roof and ceiling of the RV. This opening must be located
between the roof reinforcing members.
2. Mark a 14-1/4" x 14-1/4" (±1/8") square on the roof and carefully cut the opening.
3. Using the roof opening as a guide, cut the matching hole in the ceiling.
4. The opening created must be framed to provide adequate support and prevent air from being drawn from the roof
cavity. Lumber 3/4" or more in thickness must be used. Remember to provide an entrance hole for power supply
wiring and thermostat cable.
5. The 14-1/4" x 14-1/4" (±1/8") opening is part of the return air system of the air conditioner/heat pump and must be
finished in accordance with NFPA Standard 501C Section 2.7.
6. Route a copper 12 AWG (max. length 24'), with ground, 120 VAC supply line from the fuse or circuit breaker box to the roof
opening.
a. This supply line must be located in the front portion of the 14-1/4" x 14-1/4" (±1/8") opening.
b. The 120 VAC power supply MUST be on a separate 20 amp Time Delay Fuse or HACR Circuit Breaker for
models 520 except 520300, 530, 579, 590, 591, 59516, 600, and 630 series and a 15 amp Time Delay Fuse or
HACR Circuit Breaker for models 520300, 59528, 59529, and 59530 series.
c. Make sure at least 15" of supply wire extends into the roof opening. This ensures easy connection at the junction box.
d. Wiring must comply with all National, State and Local Wiring Codes.
e. Use a steel sleeve and a grommet or equivalent method to protect the wire where it passes into the opening.
7. See Section 6. Comfort Control Center, Remote Sensor and Cable Installation.
5. AIR DISTRIBUTION SYSTEM INSTALLATION
There may be electrical wiring between the
roof and the ceiling. Disconnect 120 VAC
power cord and the positive (+) 12 VDC ter-
minal at the supply battery. Failure to follow
this instruction may create a shock hazard
causing death or severe personal injury.
8
CCC Ducted Installation Instructions