atwood 8500-IV Series Furnace (8516, 8520, 8525, 8531, 8535) - Manuel (Page 3)

3
Required Minimum Discharge - (also see STATIC PRESSURE TEST )
MODELS REQUIRED DISCHARGE
8516-IV, 8520-IV ............................................................24in 2
8525-IV & 8531-IV ........................................................36in 2
8535-IV ..........................................................................48in 2
ALL MODELS - TOP OR BOTTOM DISCHARGE SYSTEMS ..................48in 2
8525-IV, 8531-IV, 8535-IV VERTICAL INSTALLATION ..............48in 2
( EXCEPT WHEN USING THE THREE REAR DUCT OPENINGS OR MODELS WITHOUT DOOR )
• See MINIMUM CLEARANCE TO FLOORBOARDS , WALLS & SIMILAR COMBUSTIBLE
BUILDING MATERIALS .
• Each 4-inch duct opening provides 12 in 2 of discharge area. Provide
an extra 12 in 2 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 - INCH flexible 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.
Hard Ducting Floor 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 INSTALL
- BOTTOM / TOP DISCHARGE OR VERTICAL BOTTOM ( FIG 5 )
1. Remove bottom/top discharge cover plate. This ducting option
must be connected to a ducting system. FIG 15 #4 - GASKET AND
PLENUM PLATE is available when attaching furnace.
2. If cutout is required:
FLOOR CUTOUT
BOTTOM DISCHARGE ( FIG 5 ) A B C D
8-1/4˝ 9-1/2˝ 6-1/4˝ 1/4˝
3. Fasten plenum plate (5-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 (5-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.
OPTIONAL INSTALLATION - EXTENSION BOX KIT ( FIG 6 )
FIG 15 #7 Extension Box #7 and FIG 15 #54 Plenum Plate may be
used for top or bottom discharge installation. A casing extension box
adds 6˝ of depth to furnace.
1. Remove three knockouts from rear of furnace.
2. If cutout is required:
FLOOR CUTOUT
( FIG . 6 ) A B C D E
EXTENSION BOX 18˝ 1/2˝ 5˝ 16˝ 1/4˝
3. Place extension box with foam gasket against furnace, making
sure the three openings are enclosed within extension box. With
extension box held in place, secure with two 1/2˝ sheet metal screws.
4. Fasten plenum plate over cutout.
5. Position gasket on plenum plate.
6. Set furnace on gasket, make sure gasket remains in position.
7. Fasten extension box to floor with two 1/2˝ sheet metal screws.
8. Additional ducting can be used to maintain correct static pressure.
OPTIONAL INSTALLATION - FLEX ADAPTER KIT ( FIG . 7 )
A flex adapter FIG 15 #26 may be used to provide more flexibility for
alignment of discharge opening on hard duct systems. This system
can be used on all models installed horizontally or vertically provid-
ing ducting from rear of furnace without using side ducts.
1. Remove three knockouts from rear of furnace.
2. If cutout is required, use placement and cutout dimensions for the
EXTENSION BOX ( FIG . 6 ).
3. Install duct adapters (7-A) in each opening.
4. Place flex adapter plate (7-C) with foam tape against hard ducting,
making sure openings line up.
5. With plate held in place, fasten plate to ducting (7-D).
6. Install three duct adapters into flex adapter plate.
7. Attach flexible ducting (7-B) from furnace to flex adapter plate and
secure ducting in place.
8. Additional ducting can be used to maintain correct static pressure.
PROPANE GAS CONNECTION ( FIG . 1 )
1. Connect gas line to brass fitting on right side of furnace. Be sure all
male pipe threads, other than flare fittings, are treated with a sealing
compound resistant to the action of propane (LP) gas.
DO NOT put
sealing compound on flare fittings.
WITH DOOR ONLY
• Remove slide plate (1-E) and gas inlet plug (1-F) from furnace.
• Insert gas line (1-G) through gas inlet plug (
DO NOT CUT ).
• Connect gas line through gas inlet plug inside furnace casing
immediately ahead of gas control valve.
• A 1/8˝ N.P.T. plug is accessible for test gauge connection on gas
valve assembly.
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 brass fitting and flare nut when tightening
gas line to brass fitting. DO NOT twist valve assembly ( FIG . 8 ).
ELECTRICAL CONNECTION ( FIG . 14)
ƽ
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
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
ƽ
CAUTION
PROPERTY DAMAGE
•
This connection is for low-voltage battery or direct current only. Do
not connect to 120- or 240- volts AC.