Reznor UDBS Unit Installation Manual - Manual (Page 8)

Form I-UDB, P/N 202658 R14, Page 8
4.0 Clearances
and
Dimensions
4.1 Clearances
FIGURE 2 -
Installing
High Altitude
Pressure Switch
required above
6000 ft (1830M)
elevation
Instructions for Changing Pressure Switch
1. In the control compartment, locate the pressure switch.
2. Mark and disconnect the two wires attached to the pressure switch.
3. Disconnect the sensing tubes from the pressure switch.
4. Locate the two screws holding the switch mounting bracket. Remove the screws and
the pressure switch. Save the screws.
5. Using the same screws, install the high altitude pressure switch. Attach the sensing
tubes and wires.
Pressure
Switch
Model UDBP
Size
30 45 60 75 100 125 150 175 200 225 250 300 350 400
High Altitude Switch P/N 197031 197032 197031 201160
Negative Pressure OFF
Setpoint ("w.c.)
0.35 0.45 0.35 1.05
Label color Purple Pink Purple Brown
Model UDBS
Size
30 45 60 75 100 125 150 175 200 225 250 300 350 400
High Altitude Switch P/N 197031 197032 196362 197032 197031 197030 197031 201160
Differential Pressure
OFF Setpoint ("w.c.)
0.35 0.45 0.55 0.45 0.35 0.40 0.35 1.05
Label color Purple Pink White Pink Purple Green Purple Brown
Downturn Nozzle Kits,
Option CD 2, 3, 4, or 5
Follow the instructions with the kit to install. Additional length beyond the front of the
unit is shown in FIGURE 3.
FIGURE 3 - With Optional Downturn Nozzle, Dimension “A”
3.0 Uncrating and
Preparation
(cont’d)
3.2 Preparing for Installation (cont’d)
A A
With 25-65°
downturn
with or
without
vertical
louvers
(Option
CD2 or CD4)
With 50-90°
downturn
with or
without
vertical
louvers
(Option
CD3 or CD5)
Dimension A
UDBP and
UDBS Sizes
Options CD2 & CD4 Options CD3 & CD5
inches mm inches mm
30, 45 7-1/8 181 12-3/8 314
60, 75 8-5/8 219 15 381
100, 125 12-5/8 321 21-7/8 556
150, 175, 200 11-1/2 292 19-7/8 505
225, 250 14-1/2 368 25-1/8 638
300, 350, 400 18-1/2 470 32 813
Units must be installed so that the clearances in FIGURE 4 are provided for com-
bustion air space, inspection and service, and for proper spacing from combustible
construction. Clearance to combustibles is defined as the minimum distance from the
heater to a surface or object that is necessary to ensure that a surface temperature of
90°F above the surrounding ambient temperature is not exceeded.
UDBP and UDBS
Sizes
30-125 150-400
inches mm inches mm
Top* 6 152 14 356
Flue Connector 6 152 6 152
Access Panel 18 457 18 457
*Non-Access Side 24 610 24 610
Bottom 1 25 1 25
Rear 18 457 18 457
REZNOR
Top clearance is from top
of the heater cabinet.
Non access side
clearance is
from side of the
heater cabinet.
FIGURE 4 - Clearances
If the pressure switch needs to be changed, do that before the heater is operated; fol-
low the instructions in FIGURE 2.