Reznor MAPS II Unit Installation Manual - Manual (Page 50)

Form I-MAPS II, Page 50
9. Optional Equipment including Heat Sections (cont'd)
9.4 Optional Gas-
Fired Duct
Furnace Curb
Section, Model
JHUP-0250
(natural gas
only)
The Model JHUP-0250 duct furnace curb section includes a 250 BTUH gas-
fired duct furnace. The curb section fits on a Cabinet B roof curb and mates
to a Cabinet B Model RDCA or RDDA with a Size 250 heat section, placing
a second heat exchanger in the discharge airstream. The Model JHUP-0250
duct furnace curb section adds 23-1/8" (587mm) to the height as shown in
FIGURE 40B.
The duct furnace requires a separate gas line; gas connection is 1/2". See
gas supply entrance location in FIGURE 40B. Refer to Paragraph 9.3.2.1 for
gas supply piping and pressure requirements. Since the Size 250 duct furnace
burner is the same as the burner on the unit and operates only at high fire,
manifold pressure information is the same as for a Size 250 gas heat section
at full fire.
The ignition system is the same as in Paragraph 9.3.3 and the vent/combustion
air is the same as in Paragraph 9.3.4. The high temperature limit control shown
in FIGURE 40A functions the same as in Paragraph 9.3.5.
Field wiring is required. Check the wiring diagram for field-wiring requirements.
Follow the wiring diagram to connect the field-supplied wiring.
1/2” Gas Connection
Flue Collection Box
Heat Exchanger Assembly
Gas Valve
Gas Valve
Venter Assembly
Burner
Side and End Views of the Duct Furnace Curb
Section showing Limit Control Location and
Entrance for Natural Gas
Limit Control Location
(with Door Removed)
Gas
Supply
Entrance
(natural
gas only)
Front View of JHUP
Duct Furnace
with Access
Panel Removed
Duct Furnace Sequence of Operation:
The JHUP Series duct furnace can
only be energized after the main unit
DSI control has enabled operation of
the integral heat section and the
remote temperature controller’s sensor
initiates a call for heat. When both of
these conditions are met, the JHUP
duct furnace will be energized to
operate at full fire only.
FIGURE 40A - Duct Furnace Curb Heater Gas Train and Limit Control Location