13
Through-the-Floor Return Air System (Ducted)
1. Prepare Floor Opening(s):
a. Mark fl oor openings as shown in Figure 5 (page 9).
Provide minimum clearances at rear and left side
walls of closet for installation of furnace and wiring.
b. Cut fl oor opening on outside edge of marked line
so that opening is slightly larger than area marked.
c. Additional provisions may be necessary for optional
air conditioning if refrigerant lines are installed other
than at the front of the furnace.
2. If return air duct is made of combustible material, locate
a pan fabricated of non-combustible material with 1”
upturned fl anges under furnace return air opening.
3. Route 240V supply circuit(s) and 24V wiring to closet.
See Figure 21 (page 18) for appropriate locations.
4. Position optional coil cabinet over fl oor cutout and
secure with three or more fasteners.
5. Position furnace onto coil cabinet and secure with two
or more fasteners.
6. Use optional upfl ow duct connector or fi eld supplied
connector to attach furnace to overhead supply duct.
See Figure 16.
Figure 16. Over-the-Floor Return Air System
with Upfl ow Stand
Upflow Duct
Connector
Furnace
Filter
(one obtained
from furnace)
Upflow Stand
ELECTRICAL WIRING
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to follow safety warnings exactly could
result in serious injury or property damage.
Improper servicing could result in dangerous
operation, serious injury, death or property
damage.
• Before servicing, disconnect all electrical
power to furnace.
• When servicing controls, label all wires prior
to disconnecting. Reconnect wires correctly.
• Verify proper operation after servicing.”
WARNING:
• Electrical connections must be in compliance with all
applicable local codes and the current revision of the
National Electric Code (ANSI/NFPA 70).
• For Canadian installations the electrical connections
and grounding shall comply with the current Canadian
Electrical Code (CSA C22.1 and/or local codes).
Line Voltage Wiring
IMPORTANT NOTE:
Proper line voltage polarity must be
maintained for the control system to operate correctly.
Verify the incoming neutral line is connected to the
white wire and the incoming HOT line is connected
to the black wire. The furnace will not operate unless
the polarity and ground are properly connected.
IMPORTANT:
Circuit breakers installed in this unit provide
short-circuit protection of the internal wiring
and serve as a disconnect. The circuit breakers
DO NOT provide over-current protection of the
supply wiring and may be sized larger than
the branch circuit protection. Overcurrent
protection of the supply wiring is provided by
the breaker in the distribution panel and must
be sized as shown in Table 7 (page 20).
It is recommended that the line voltage (240 VAC) to
the furnace be supplied from a dedicated branch circuit
containing the correct fuse or circuit breaker for the furnace.
See Table 7 (page 20).for minimum circuit ampacity and
maximum over-current protection. See unit wiring diagrams
(Figures 23 - 26, pages 21 - 24) for wiring details. Electrical
components are shown in
Figure 20 (page 17).
Supply
circuit requirements are listed at the top of page 14:
