Nortek MG1 Series, Installation Instructions Manual

Page: 9 / 32

9
DUCT
CONNECTOR
SCREWS
MOUNTING
PLATE
FUEL LINE
HOLE
FUEL LINE
HOLE
14” SUPPLY
CONNECTION
Figure 13. Round Duct Connector Installed
MTG. PLATE TABS
SLIDE FURNACE
ALL THE WAY BACK
ONTO MTG. PLATE
SUPPLY AIR DUCT
Knockout Over Holes
SECURE FURNACE
WITH 2 FASTENERS AT FRONT
CORNER HOLES
Figure 14. “A” & “B” Cabinet Furnaces
FUEL LINE HOLES
MTG. PLATE TABS
SLIDE FURNACE
BACK AGAINST
MTG. PLATE
SECURE FURNACE
WITH 2 FASTENERS
AT FRONT CORNER HOLES
SUPPLY
AIR DUCT
Figure 15. “A” Cabinet Furnace on Coil Cabinet
• American National Standard (ANSI-C1/NFPA-70) and/or
CSA 22.1 Canadian Electric Code Part 1 for all electrical
field wiring.
• Units have been certified under standards UL 307A & B,
UL727-1999, ANSI Z21.47/CSA 2.3, and CSA B140.10.
General Information
• The furnace must be leveled at installation and attached
to a properly installed duct system.
Do not use the
back of the furnace for return air. See page 7
for circulating requirements.
• The furnace must be installed so that all electrical
components are protected from water
• The dimensions of the room or alcove must be able to
accommodate the overall size of the furnace and the
installation clearances listed in Table 1, (page 6)
and Figure 1 (page 5)
• The furnace must be installed upstream from a
refrigeration system.
• MG1 series gas furnaces are certified for use on wood
flooring or supports, but must be installed on top of a
duct connector. This factory supplied accessory must
be installed in the floor cavity and attached to the supply
air duct before the furnace is installed.
Locating & Cutting Duct Openings
Floor cut-outs and fuel line holes must be carefully located
to avoid misalignment of the furnace, and vent piping.
To locate standard ducts see Figure 6 (page 8) . For
round ducts, see Figure 7 (page 8) .
1. Measure 10” from the rear wall or alcove and mark the
centerline of the cut-out on the floor.
2. Using the centerline as a starting point, draw the rest
of the duct cut-out to the dimensions shown in Figure
6 or Figure 7 .
3. Cut out the floor opening 1/16” larger than the actual
cutout drawn. This will allow some clearance when
installing the duct connector.
4. Measure from the top of the floor down to the top of the
supply air duct to obtain the depth of the floor cavity.
NOTE: The depth of the floor cavity shown as “X” in
Figure 9 (page 8) will determine the correct duct
connector.
5. Determine which duct connector to use from Table 2,
(page 9) .
6. Measure and drill gas hole and cut out for cooling coil
(if applicable). See Figure 6 or Figure 7 .
IF FLOOR
CAVITY
“X” IS:
DUCT CONNECTOR
TYPE & PART NUMBER
STANDARD DUCT ROUND DUCT
7/8” / (22) 901987A 904008
2” / (51) 901988A N/A
4-1/4” / (108) 901989A 904010
6-1/4” / (159) 901990A 904011
8-1/4” / (210) 901991A 904012
10-1/4” / (260) 901992A 904013
12-1/4” / (311) 901993A 904014
NOTE: Dimensions shown as Inches / (Millimeter)
Table 2. Duct Connector Sizes
Standard Duct Connector Installation
The standard duct connector is designed for use on
ducts 12” in width. Ducts narrower than 12” may not
allow sufficient clearances for this type of installation. See
Alternate Attachment Method section below.
1. Center the duct connector in the floor opening with
bottom tabs resting on top of the supply air duct.
2. Mark the cut-out area on the supply air duct by tracing
around the connector tabs of the duct connector. See
Figure 8 (page 8) .
3. Remove the duct connector and cut out the marked
area of the supply air duct 1/4” larger the actual cutout
drawn.