Connecting Electrical Supply; Connecting Gas Supply; Connecting Thermostat - Suburban NT-16SEQ Installation Manual

Reduced Front Clearance
Front 12" NT-16SEQ
Front 18" NT-20SEQ
Note: Must provide an additional 12 sq. in. of return air when side clearance
(See Figure 9)
3. When an appliance is installed directly on carpeting, tile, or other combustible
material other than wood flooring, the appliance shall be installed on a metal or
wood panel extending the full width and depth of the appliance. If preferred, the
carpeting, tile or combustible materials, other than wood may be cut away the
full length and depth of the appliance plus the appliance minimum clearances to
combustibles.
4. Cut or frame an opening in the coach cabinetry 10
Figure 2 or Figure 3.
5. Slide the front of the furnace through the opening and extend it beyond the
coach cabinetry 1 / " as shown in Figure 2 or Figure 3.
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6. Determine "X" dimension as shown in Figure 1.
7. Determine "Y" dimension as shown in Figure 1.
8. If X - Y is less than 21", then an opening 9
inner wall only. DO NOT CUT THROUGH COACH SKIN. (See Figure 2.) Next,
locate the center line of the exhaust and intake tube. Cut two 2
through the outer skin as shown in Figure 4.
NOTE: Whenever the furnace cabinet is installed through the outside wall, the
return air louvers on the furnace cabinet must not be blocked. The maximum
projection of the furnace cabinet into the wall is 2
NOTE: Furnace cabinet approved for 0" clearance to combustible materials rear
2 / " of furnace cabinet.
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9. If X - Y is 21" or greater, two methods may be used to install the furnace.
a. Cut a 4" x 7 / " opening through combustible wall as shown in
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Figure 3. DO NOT CUT THROUGH TRAILER SKIN. Next, locate the center line
of the exhaust and intake tube. Cut two 2
(See Figure 4.)
b. If you do not wish to cut the 4" x 7
of the exhaust and intake tube as shown in Figure 4. Next, cut two 2
holes through trailer skin and also the combustible wall of the trailer as illustrated
in Figure 6. Care must be taken when locating the center line of the exhaust and
intake tube as well as when cutting the holes in order to assure a 3/8" clearance
around the exhaust and intake tube to combustible materials.
10. Refer to the chart in Figure 1 and select the range for which the 'X' dimension
falls. The intake tube length directly to the left of the selected range is the length
required. NOTE: The 7 / " length exhaust tube assembly will accommodate all
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approved installation depths - only the intake tube must be ordered when needed.
Under no circumstances should the standard 5" intake tube be cut or altered to
adapt to the 21" - 23 / " range.
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11. Secure furnace to the floor using the two holes provided in furnace cabinet.
(See Figure 2 or Figure 3.)
12. NOTE: OPTIONAL DISCHARGE DUCT ADAPTER -The cabinet has a 4"
diameter knockout on the left side of cabinet. (See Figure 6A.) A 4" diameter
connector can be attached to this location to provide a warm air discharge duct.
(Not to exceed 10" in length.)

CONNECTING GAS SUPPLY

A / " flare connection is provided on the right side of the furnace for the gas supply
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connection to the furnace.
Connect the gas supply to the furnace at the manifold, following the suggestions
outlined below. It will be necessary to hold the flare fitting on the furnace manifold
when connecting or loosening gas lines.
NOTE: Be sure all male joints have been treated with a sealing compound
resistant to the action of liquefied petroleum (LP) gas.
In order to maintain a check on gas supply pressure to the furnace. Suburban
advises the installer to provide a
immediately upstream of the gas supply connection to the furnace.
NOTE: The appliance must be disconnected from the gas supply piping system
during any pressure testing of that system at test pressure in excess of
The appliance must be isolated from the gas supply piping during any pressure
testing of the gas supply piping system at test pressure equal to or less than
WARNING! All joints must be checked for leaks. Do not use open flame to
check for leaks! Use a soap and water solution.
Top 1" Floor / "
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Side 0"*
is 1" - 8"
/ " x 10 / " as shown in
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16 16
/ " x 9 / " must be cut through the
5 3
8 8
/ " diameter holes
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/ ". (See Figure 2.)
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/ " diameter holes through trailer skin.
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/ " opening, locate the center line
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/
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/ " NPT plug tap for test gauge connection
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/
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CONNECTING ELECTRICAL SUPPLY

CAUTION: These furnaces are designed for a negative ground 12 volt
D.C. system only. Do not attempt to alter the furnace for a positive ground
system or connect the furnace directly to 115 volts A.C. Damage to furnace
component parts will occur. Connect only to a protected circuit fused for
not more than 7.5 amps.
Be sure all wiring to the furnace is of heavy enough gauge to keep the voltage
drop through it to a minimum and to provide enough power for start-up surge. No.
12 gauge wire is recommended.
If any of the original wire that is supplied with the appliance must be replaced, it
must be replaced with Type 105° C or its equivalent.
Connect the power supply to the red and yellow wires on the right side of the
furnace. The wires are color coded, red for positive (+) and yellow for negative
(-). This polarity must be observed so the furnace motor will run with the proper
direction of rotation to insure correct air delivery. (See wiring diagram.)
If the furnace power supply is to be from a convertor, we recommend that the
convertor system used to power the furnace be wired in parallel with the battery.
This will serve two purposes:
1. Provide a constant voltage supply to the furnace.
2. Filter any A.C. spikes or volt surges.
NOTE: Furnace models NT-16SEQ AND NT-20SEQ are equipped with an electric
ignitor device that has an energy consumption of.1 amps at 12 volts D.C.

CONNECTING THERMOSTAT

The thermostat used with this unit must have NO voltage output to return leg when
there is not a call for heat or in the "OFF" setting.
Locate the room thermostat approximately 4
bulkhead where it is not affected by heat from any source except room air.
Connect the thermostat wires to the blue wires on the right side of the furnace.
(See wiring diagram.) If your furnace is equipped with a thermostat that has
an adjustable anticipator, the anticipator should be set at .7 amps. If you desire
longer heating cycles, adjust the anticipator to a higher setting. If you desire
shorter heating cycles, adjust the anticipator to a lower setting. Adjustments to the
anticipator setting should be made in .5 amp increments.
INSTALLING VENT ASSEMBLY
" diameter
The vent outlet must be installed so it is in the same atmospheric pressure zone
as the combustion air intake. The exhaust and intake tubes must be installed
from the outside, pass through the RV skin and slide onto the furnace exhaust
and intake.
WARNING! Do not alter the vent assembly supplied with this furnace.
Any modifications will result in improper installation which could cause
unsafe furnace operation. Never operate furnace with vent covered.
CAUTION! Combustion air must not be drawn from the living area. All air for
combustion must be drawn from the outside atmosphere. All exhaust gases
must be vented to the outside atmosphere - never inside the RV. Therefore,
it is essential to insure that the vent cap and tube assemblies are properly
installed.
1. Apply caulking to RV skin behind vent cap as shown in Figure 6. Apply caulking
generously around perimeter of vent cap and across center as shown.
2. Insert intake tube through RV skin and slide it onto the furnace intake (See
Figure 1.) Minimum tube overlap of
3. Insert vent cap exhaust tube through RV skin and slide it onto the furnace
exhaust (See Figure 1.) Minimum tube overlap of 1
4. Attach vent cap assembly to outer skin of RV with the six (6) screws provided.
Do not install vent assembly upside down. The word "Suburban" must be right
side up.
/ PSIG.
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PSIG.
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/ feet above the floor on an inside
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/ " is required.
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/ " is required.
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