VR8200, VR4200
STARTUP AND CHECKOUT
11
68-0046—4
4. If the desired outlet gas pressure or gas flow rate
cannot be achieved by adjusting the gas control, check the
gas control inlet pressure using a manometer at the inlet
pressure tap. If the inlet pressure is in the normal range
(refer to Table 7 or 8), replace the gas control. Otherwise,
take the necessary steps to provide proper gas pressure to
the gas control.
Step-Opening Pressure Regulator and Delayed and
Step-Opening Pressure Regulator
1. The gas control outlet pressure should match the
manifold pressure listed on the appliance nameplate.
2. With main burner operating, check the gas control
flow rate using the meter clocking method or check the gas
pressure using a manometer connected to the gas control
outlet pressure tap. Refer to Figs. 2 and 3.
3. If necessary, adjust the pressure regulator to match
the appliance rating. Refer to Table 7 or 8 for factory-set
nominal outlet pressures and adjustment ranges.
a. Remove the pressure regulator adjustment cap
screw.
TABLE 7—PRESSURE REGULATOR SPECIFICATION PRESSURES IN INCHES WC.
Outlet Pressure
Nominal
Nominal Factory
Setting Range
Inlet
Setting
Pressure
Full
Full
Model
Type of Gas
Range
Step
Rate
Step
Rate
Standard,
NATURAL
5.0 - 7.0
—
3.5
—
3.0 - 5.0
Slow-
LP
12.0 - 14.0
—
10.0
—
8.0 - 12.0
opening
Step-
NATURAL
5.0 - 7.0
0.9
3.5
—
3.0 - 5.0
opening
LP
12.0 - 14.0
2.2
10.0
—
8.0 - 12.0
TABLE 8—PRESSURE REGULATOR SPECIFICATION PRESSURES IN kPa.
Outlet Pressure
Nominal
Nominal Factory
Setting Range
Inlet
Setting
Pressure
Full
Full
Model
Type of Gas
Range
Step
Rate
Step
Rate
Standard,
NATURAL
1.2 - 1.7
—
0.9
—
0.7 - 1.2
Slow-
LP
2.9 - 3.9
—
2.7
—
2.0 - 3.0
opening
Step-
NATURAL
1.2 - 1.7
0.2
0.9
—
0.7 - 1.2
opening
LP
2.9 - 3.9
0.9
2.7
—
2.0 - 3.0
CHECK SAFETY SHUTDOWN PERFORMANCE
WARNING
FIRE OR EXPLOSION HAZARD,
CAN CAUSE PROPERTY DAMAGE,
SEVERE INJURY, OR DEATH.
Perform the safety shutdown test any time work
is done on a gas system.
!
1. Place gas control knob in PILOT position. Main
burner should go off and pilot should remain lit.
2. Extinguish pilot flame. Pilot gas flow should stop
within 2-1/2 minutes. Safety shutoff or pilot gas proves
complete shutdown since safety shutoff valve permits
main burner and pilot gas flow.
3. Relight pilot burner and operate system through one
complete cycle to assure all controls operate properly.
b. Using a screwdriver, turn the inner adjustment
screw clockwise to increase or counter-
clockwise
to decrease the main burner gas
pressure.
c. Always replace the cap screw and tighten firmly
to assure proper operation.
4. If desired outlet pressure or flow rate cannot be
achieved by adjusting the gas control, check the inlet
pressure using a manometer at inlet pressure tap or
upstream of the gas control. If the inlet pressure is in the
normal range (refer to Table 7 or 8), replace the existing
gas control. Otherwise, take the necessary steps to pro-
vide proper gas pressure to the gas control.
5. Carefully check main burner lightoff at the step
pressure. Ensure the main burner lights smoothly and
without flashback to the orifice and that all ports remain
lit. Cycle the main burner several times, allowing at
least 30 seconds between cycles for the regulator to
resume the step function. Repeat after allowing main
burner to cool. Readjust the full rate outlet pressure if
necessary to improve lightoff characteristics.