Ducting systems can include any combination of discharge openings, as long as static pressure and minimum discharge area requirements are met.
ALL MODELS - (also see STATIC PRESSURE TEST) | 48 IN2 |
REQUIRED MINIMUM DISCHARGE |
REQUIRED MINIMUM RETURN AIR | 80 IN2 |
•See MINIMUM CLEARANCE TO FLOORBOARDS, WALLS & SIMILAR COMBUSTIBLE BUILDING MATERIALS.
•Each 4-inch duct opening provides 12 in2 of discharge area. Provide
an extra 12 in2 of non closeable duct discharge area for each closeable register used.
•Use of 2˝ ducts does not count toward achieving minimum discharge requirements. Ducting in dead air space with no return air, such as holding tank areas, does not count toward achieving minimum dis- charge requirements.
•Adjust ducting installation to obtain air rise of 100˚F-130˚F.
Flexible Ducting Systems
When designing Flexible Duct Systems:
•avoid sharp bends or crushed ducts
•stretch all ducts and run them directly to outlets, keeping quanti- ty and angles of bends to a minimum
1.Remove knockout plates from desired outlets.
2.Attach a duct adapter to each opening, by inserting flange over cas- ing, locking the tab into casing slot and turning adapter 90˚.
3.Attach and secure FOUR-INCHflexible ducts to adapters.
4.Run ducts to desired location within RV, secure to registers.
5.Additional ducting may be needed to maintain correct static pressure.
Floor Hard Ducting Systems
When designing Hard Ducting Systems:
•undersize ducting will cause high temperature limiting
•oversize ducting will cause inadequate air flow from registers
•when hard ducting is 1-1/2˝ in depth, an additional flex duct may be needed to maintain installation static requirements
•DO NOT install floor registers within 2 feet of return air openings.
OPTIONAL INSTALLATION - BOTTOM DISCHARGE (FIG 4)
1.Remove bottom discharge cover plate. This ducting option must be connected to a ducting system. FIG 3 (parts breakdown) #40 - GASKET AND PLENUM PLATE KIT is available when attaching furnace.
2. If cutout is required: | | FLOOR CUTOUT | |
BOTTOM DISCHARGE | A | B | C | D |
HORIZONTAL-WITHOUT DOOR (FIG 4) | 18-20 1/2˝ | 5-1/2˝ | 10-1/2˝ | 3/4˝˝ |
3.Fasten plenum plate (3-E) over floor cutout. If a gasket and plenum plate are not used, seal furnace to hard duct system mak- ing sure seal is air-tight and continue with STEP 5.
4.Position gasket (3-F) on plenum plate.
5.Set furnace on gasket, make sure gasket remains in position.
6.Additional ducting can be used to maintain correct static pressure.
VERTICAL
There is only one ducting option when using vertical installation. Option 1 has already been illustrated, the other configuration is using top two ducts and two ducts off the back of the casing. This is the only configuration allowed with vertical installation (FIG 3A).
PROPANE GAS CONNECTION (FIG. 2)
1.Connect gas line to fitting on top rear of furnace. Be sure all male pipe threads, other than flare fittings, are treated with a sealing com- pound resistant to the action of propane (LP) gas. DO NOT put sealing compound on flare fittings.
2.A 3/8˝ flared fitting connection is provided at gas control valve inlet for gas supply connection to furnace. The gas supply line of the fur- nace must be of adequate size to provide 11˝ W.C. gas pressure.
This pressure must be maintained under maximum flow conditions with all gas appliances in operation.
3.Use two wrenches to hold fitting and flare nut when tightening gas line to fitting. DO NOT twist fittings (FIG. 2).
ELECTRICAL CONNECTION
WARNING
INJURY OR PROPERTY DAMAGE
•Label all wires before disconnecting for servicing. Wiring errors can cause improper and dangerous operation. Verify proper oper- ation after servicing.
•Disconnect electrical power before servicing.
Conductor Sizing Table - MAX. 10% VOLTAGE DROP - (12 VDC)
CURRENT DRAW (AMPS) | | | | | | | | |
| 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 15 | 16 |
| | |
GAGE | MAX. LENGTH OF SAE CONDUCTOR (IN FEET) FROM SOURCE TO DEVICE | |
18 | 57 | 43 | 34 | 29 | 25 | 21 | 19 | 17 | 11 | - |
16 | 87 | 65 | 52 | 43 | 37 | 33 | 29 | 26 | 17 | - |
14 | | | | | | 52 | 46 | 41 | 28 | 21 |
CAUTION
PROPERTY DAMAGE
•This connection is for low-voltage battery or direct current only. Do not connect to 120- or 240- volts AC.
This furnace is designed for negative ground 12 volts DC only. DO NOT attempt to alter furnace for a positive ground system or connect the furnace directly to 120 volts AC. Damage to furnace components will occur and warranty will be voided.
Use a minimum of 14 GA wire to minimize voltage drop. Furnace must be installed so electrical components are protected from water. To make electrical connections see wiring diagram FIG. 4.
1.Route wiring to left side of furnace.
2.Connect red wire to positive side of power supply.
3.Connect yellow wire to grounded side of power supply.
4.Connect blue wire to thermostat using 22-18 GA stranded wire.
5.Connect the green wire to the green thermostat lead using mini- mum 22-18 GA stranded wire.
See instruction with thermostat for complete wiring directions.
For best furnace performance when power supply is from a converter equipped with a charging port, wire converter to furnace parallel with battery. This provides consistent voltage to furnace, increasing compo- nent life, filtering power surges and AC spikes.
Each unit ships with a standard field harness connection with 12˝ wire leads.
NOTE: All units are supplied with a power switch which when turned off for servicing will remove power through furnace wiring. Switch must be in ON position for furnace to operate FIG 2-G.
POWER SUPPLY
Atwood Mobile Products highly recommends the use of an electronic (solid state) converter with clean, clear power output. This will assure the life of the electronic controls and motor life could be extended as much as 500% beyond typical linear converter applications.
