Lennox MPD35ST-NM-B Installation Instructions Manual page 3

Millivolt Models - The millivolt appliances are
manually controlled and feature a spark igniter
(piezo) that allows the appliance's pilot gas to
be lit without the use of matches or batteries.
This system provides continued service in the
event of a power outage.
Millivolt models come standard with a manu-
ally-modulated gas valve; flame appearance and
heat output can be controlled at the gas valve.
The BTU Input for these appliances is shown
in Table 1.
BTU Input - Millivolt Models
Input (BTU) Manually-Modulated Gas
Valves (millivolt models)
Models Fuel
Type
MPD35ST/PF-NM Natural
MPD35ST/PF-PM Propane
Table 1
Electronic Models - Electronic models have
a fixed rate gas valve. The BTU input for the
electronic models is shown in Table 2.
BTU Input - Electronic Models
Input (BTU) - Fixed Rate
(electronic models)
Models Fuel
Type
MPD35ST/PF-NE Natural
MPD35ST/PF-PE Propane
(if field converted)
Table 2
Gas Pressure - All Models
Tables 3, 4 and 5 show the appliances' gas
pressure requirements:
Inlet Gas Supply Pressure
(all models)
Fuel # Minimum
5.0" WC
Natural Gas
(.24 kPa)
.0" WC
Propane
(2.74 kPa)
Table 3
Manifold Gas Supply Pressure
Fuel #
Natural
Gas
Propane
Table 4
Manifold Gas Supply Pressure
Fuel #
Nat. Gas
Input Rate
(BTU / HR)
Propane
30,000 high
Table 5
23,000 low
Test gauge connections are provided on the
28,000 high
front of the millivolt gas control valve, identi-
22,000 low
fied IN for the inlet and OUT for the manifold
side. A 1/8" NPT Test gauge connection
is provided at the inlet and outlet side of
the electronic gas control valve.
These appliances must be isolated from the
gas supply piping system (by closing their
individual manual shut-off valve) during any
pressure testing of the gas supply piping
system at test pressures equal to or less than
1/2 psig (3.5 kPa).
Input Rate
(BTU / HR)
These appliances and their individual shut-off
valves must be disconnected from the gas
30,000
supply piping system during any pressure
testing of that system at pressures greater
than 1/2 psig (3.5 kPa).
28,000
Orifice Sizes - Sea Level to High Altitude
(All Models)
These appliances are tested and approved for
installation at elevations of 0-4500 feet (0-1372
meters) above sea level using the standard burner
orifice sizes (marked with an "*" in Table 6 ). For
elevations above 4500 feet, contact your gas
supplier or qualified service technician . Install
the appliance according to the regulations of
Maximum
the local authorities having jurisdiction and, in
0.5" WC
the USA, the National Fuel Gas Code NFPA 54
(2.6 kPa) / ANSI Z223.1 - latest edition or, in Canada, the
CAN1-B149.1 and .2 codes - latest edition.
3.0" WC
(3.23 kPa)
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
(millivolt models)
Low High
(Lo) 2.2" WC (Hi) 3.5" WC
(.55 kPa) (.87 kPa)
(Lo) 6.3" WC (Hi) 0.0" WC
(.57 kPa) (2.49 kPa)
(electronic models)
Maximum Manifold Pressure
(Hi) 3.5" WC (.87 kPa)
(Hi) 0.0" WC (2.49 kPa)
Burner Orifice Sizes (all models)
Natural
Elevation
Gas
Feet (meters)
drill size (inches)
0-4500
#37 (.04") *
(0-372)
24M00 •
Table 6
* Standard size installed at factory
• Part /Cat. Number
Gas Valve Diagrams
See Figure 1 for Millivolt models and Figure 2
For Electronic Models.
SIT Millivolt Gas Valve
Inlet Pressure Tap
HI/LO Variable
Flame Height
Manifold Pressure Tap
Adjustment
Main Gas
Pilot Adjustment
Control Knob
Screw
OFF/PILOT/ON
Figure 1
Honeywell Electronic Gas Valve
Manifold Pressure
ON / OFF Switch
Port
Electronic Gas
Control Valve
Figure 2
Massachusetts And New York City, NY Re-
quirements
These appliances are approved for installation
in the following USA locations listed in the
following:
Propane
Gas
drill size (inches)
.55 mm (.06") *
42M790 •
Inlet
Pressure
Port
3