0 mechanical (cont'd), 1 gas piping and pressures (cont'd), Pilot supply pressure – Reznor RDF Unit Installation Manual User Manual
Page 10
I-RDF, PN148384R5, Page 10
Pilot Supply Pressure
These systems are designed to operate on a natural gas pilot supply pressure of 3.5"
w.c. or propane gas of 6.0" w.c. Measure both operating pressure and pilot supply
pressure with the blower in operation.
Manifold pressure is defined as the gas pressure as measured at the burner pressure
tap. Measure manifold gas pressure with the blowers operating. Minimum gas pres-
sure at the burner is typically 4.3" w.c. for natural gas or typically 1.5" w.c. for propane
gas.
FIGURE 8 - Pressure
Tap Locations for
Measuring Manifold
and Pilot Pressure
Manifold Pressure
Gas Pressure
Switches
High gas pressure switches included in the gas train monitor gas pressure downstream
from the safety valves. If the gas pressure at this point on a system equipped with a
high gas pressure switch (standard with Manifolds BM 78, 79, 80, and 81 or Option
BP2 with other manifolds) exceeds the setpoint, the switch will open the electrical
circuit to the burner, stopping all gas flow. The high gas pressure switch is a manual
reset device.
A low gas pressure switch (Option BP3) will shutoff the gas flow if the gas pressure
drops below the setpoint of the low pressure switch. The low gas pressure switch will
automatically reset when the gas pressure rises above the setpoint.
(
NOTE: Model RDF units manufactured prior to April 1993 installed indoors with
optional gas pressure switches require a 3/4" vent line to the outdoors. Beginning with
units manufactured April 1993, the gas pressure switches incorporate a vent limiting
device and do not require venting to the outdoors.)
6.0 Mechanical
(cont'd)
Minimum Supply Gas Pressure ("w.c.) for Full Fire
Manifold Option
BM75
BM76
BM77
BM78
BM79
BM80
BM81
with Gas Control
Option
AG1
AG3
AG 30, 31, 32, 33, 36, 37, 47, 48, or 51
Manifold Size
1"
1"
1"
1"
1"
1-1/4"
1-1/4"
2"
MBH
Nat
Pro
Nat Pro
Nat
Pro
Nat
Pro
Nat
Pro
Nat
Pro
Nat
Pro
Nat
Pro
250
4.0
1.4
4.0
N/A
4.1
1.6
4.3
1.5
4.4
1.6
4.6
1.6
4.5
1.6
5.1
1.8
500
5.3
1.9
5.0
N/A
5.8
2.3
6.2
2.2
6.0
2.3
5.2
1.9
5.0
1.7
5.3
1.9
750
7.5
2.7
6.8
N/A
8.5
3.3
9.5
3.3
8.4
3.3
6.1
2.3
5.7
2.0
5.5
1.9
1000
12.4
4.7
11.7 4.6
7.4
2.8
6.7
2.4
5.8
2.1
1250
9.1
3.5
8.0
2.9
6.2
2.2
1500
11.2
4.3
9.6
3.5
6.6
2.4
1750
13.6
5.3
11.5
4.2
7.2
2.6
2000
16.5
6.3
13.7
5.0
7.8
2.8
2500
23.3
8.9
18.9
7.0
9.4
3.4
3000
11.3
4.1
6.1 Gas Piping and Pressures (cont'd)
Supply Pressure Requirement by Manifold Option (cont'd)
Inlet Pressure Tap
Valve
Valve
Regulator
Manifold Pressure Tap
Gas
Supply
Pilot
Regulator
Pilot Solenoid Valve
Pilot Pressure Tap