Daikin Rebel Applied DPSA - Burner and Gas Manifold Pressure Adjustment Instructions; 2-Stage Furnaces; 4-Stage Furnaces; Modulating Furnaces

IM 1287-6 • REBEL APPLIED ROOFTOP 154 www.DaikinApplied.com

Burner and Gas Manifold Pressure
Adjustment Instructions
2-Stage Furnaces
1. Read gas pressure P1 at the Inlet Pressure Tap of the
two stage valve (Figure 206) and conrm pressure
matches the value specied in Table 39 for your unit’s
capacity and modulation conguration. Adjust upstream
pressure reducing gas regulator as required to obtain
inlet pressure specied in Table 39.
2. In main cabinet control panel, set MicroTech 4 controller
to manual mode. Specify high re operation by setting
“Htg Stage 2” menu item to ON. Back at the furnace,
read gas pressure P2 on the burner manifold pressure
tap. Conrm P2 pressure matches the HIGH value
specied in Table 39 for your unit’s capacity and
modulation conguration. If adjustment is required, adjust
the HI regulator on the two stage gas valve (Figure 207).
3. In main cabinet control panel, set MicroTech 4 controller
to manual mode. If “Htg Stage 2” menu item is set to
ON, turn it OFF. Specify low re operation by setting “Htg
Stage 1” menu item to ON. Back at the furnace, read
gas pressure P2 on the burner manifold pressure tap.
Conrm P2 pressure matches the LOW value specied
in table S for your unit’s capacity and modulation
conguration. If adjustment is required, adjust the Lo/
Med regulator on the two stage gas valve (Figure 207).
4-Stage Furnaces
1. Read gas pressure P1 at the Inlet Pressure Tap of the
two stage valve (Figure 206) and conrm pressure
matches the value specied in Table 39 for your unit’s
capacity and modulation conguration. Adjust upstream
pressure reducing gas regulator as required to obtain
inlet pressure specied in Table 39.
2. In main cabinet control panel, set MicroTech 4 controller
to manual mode. Specify high re operation by setting all
“Htg Stage” menu items to ON. Back at the furnace, read
gas pressure P2 and P3 on the burner manifold pressure
tap. Conrm both P2 and P3 pressures match the HIGH
value specied in Table 39 for your unit’s capacity and
modulation conguration. If adjustment is required, adjust
the HI regulator on the relevant two stage gas valve
(Figure 207).
3. In main cabinet control panel, set MicroTech 4 controller
to manual mode. If any “Htg Stage” menu items are
ON, turn them OFF. Specify low re operation by
turning “Htg Stage 1” ON. Back at the furnace, read gas
pressure P2 and P3 on the burner manifold pressure
taps. Conrm both P2 and P3 pressures match the LOW
value specied in Table 39 for your unit’s capacity and
modulation conguration. If adjustment is required, adjust
the Lo/Med regulator on the relevant two stage gas valve
(Figure 207).
Modulating Furnaces
1. Read gas pressure P1 at the Inlet Pressure Tap of the
two stage valve (Figure 206) and conrm pressure
matches the value specied in Table 39 for your unit’s
capacity and modulation conguration. Adjust upstream
pressure reducing gas regulator as required to obtain
inlet pressure specied in Table 39.
2. In main cabinet control panel, set MicroTech 4 controller
to manual mode. Specify high re operation by “Htg
Valve” menu item to 100%. Continue to specify high
re operation by setting all available “Htg Stage” menu
items to ON. Back at the furnace, read the gas pressures
specied in Table 39 for your conguration on the burner
manifold pressure taps. Conrm each pressure matches
the HIGH value specied for each manifold in Table 39
for your unit’s capacity and modulation conguration.
If adjustment is required, adjust the HI regulator on the
relevant staged gas valve (Figure 207).
3. In main cabinet control panel, set MicroTech 4 controller
to manual mode. Specify low re operation by setting all
available “Htg Stage” menu items to OFF. Continue to set
low re operation by setting the “Htg Valve” menu item to
the applicable value shown in Table 41 below.
4. At the furnace, read gas pressure P2 on the burner
manifold pressure tap. Conrm P2 pressure matches the
LOW value specied in Table 39 for your unit’s capacity
and modulation conguration. If adjustment is required.
Refer to “Maxitrol EXA Star Controller” on page 155.
Table 41: Modulating Furnace Low Fire “Htg Valve” Value
Furnace
Capacity
Natural Gas (NG) 
Modulation
Low Fire “Htg
Valve” Setting
Modulation
Low Fire “Htg
Valve” Setting
200 MBH
(58.6 kW)
5:1 20% 5:1 20%
400 MBH
(117.2 kW)
5:1
20%
5:1
20%
10:1 10:1
600 MBH
(175.8 kW)
5:1 40% 5:1 40%
10:1
20%
10:1
20%
20:1 20:1
800 MBH
(234.5 kW)
10:1
20%
6:1
33%
20:1 12:1
1125 MBH
(309.1 kW)
10:1 40% 6:1 63%
20:1 20% 12:1 31%
1500 MBH
(439.6 kW)
10:1 40% 6:1 67%
20:1 20% 12:1 33%