69-1059
10
SV9540; SV9640 SmartValve™ SYSTEM CONTROLS
MAINTENANCE
WARNING
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE,
SEVERE INJURY, OR DEATH
Do not attempt to take the control apart or clean
it. Improper cleaning or reassembly can cause
gas leakage.
Regular preventive maintenance is important in applica-
tions such as in the commercial cooking and agricultural
and industrial industries that place a heavy load on system
controls because:
•
In many such applications, particularly commercial
cooking, the equipment operates 100,000 to 200,000
cycles per year. Such heavy cycling can wear out the
gas control in one to two years.
1. Carefully check the main burner lightoff. Make sure
that the main burner lights smoothly and that all
ports remain lit.
2. Check the full rate manifold pressure listed on the
appliance nameplate. Ignition system control full rate
outlet pressure should match this rating.
3. With main burner operating, check the ignition
system control flow rate using the meter clocking
method or check pressure using a manometer
connected to the outlet pressure tap on the ignition
system control. See Fig. 4.
4. If necessary, adjust the pressure regulator to
match the appliance rating. See Tables 7A and 7B
for factory-set nominal outlet pressure and
adjustment range.
a.
Remove the pressure regulator adjustment
cap screw.
b.
Using a screwdriver, turn the inner adjustment
screw clockwise
to increase or
counterclockwise
to decrease the gas
pressure to the burner.
c.
Always replace the cap screw and tighten
firmly to prevent gas leakage.
5. If the desired outlet pressure or flow rate cannot be
achieved by adjusting the ignition system control,
check the ignition system control inlet pressure
using a manometer at the ignition system control
inlet pressure tap. If the inlet pressure is in the
nominal range (see Tables 7A and 7B), replace the
ignition system control. Otherwise, take the
necessary steps to provide proper gas pressure to
the control.
NOTE:
If the burner firing rate is above 150,000
Btuh on SV9540 models (see Table 3 for
SV9640 capacities), it may not be possible
to deliver the desired outlet pressure. This
is an application issue, not a control failure.
Take whatever steps are required to
correct the situation.
6. STEP-OPENING PRESSURE REGULATORS
ONLY. Carefully check the burner lightoff at step
pressure. Make sure the burner lights smoothly
and without flashback to the orifice. Make sure all
ports remain lit. Cycle the burner several times,
allowing at least 60 seconds between cycles for
the regulator to resume the step function. Repeat
after allowing the burner to cool. Readjust the full
rate outlet pressure, if necessary, to improve
lightoff characteristics.
Nominal Inlet
Factory Set
Nominal Outlet Pressure
Setting Range
Model Type
Type of Gas
Pressure Range
Step
Full Rate
Step
Full Rate
Standard, Slow
NAT
5.0-7.0
—
3.5
—
3.0-5.0
LP
12.0-14.0
—
10.0
—
8.0-12.0
Step
NAT
5.0-7.0
0.9
3.5
None
0.7-1.7
LP
12.0-14.0
2.2
10.0
None
1.4-5.5
Nominal Inlet
Factory Set
Nominal Outlet Pressure
Setting Range
Model Type
Type of Gas
Pressure Range
Step
Full Rate
Step
Full Rate
Standard, Slow
NAT
1.2-1.7
—
0.9
—
0.7-1.2
LP
2.9-3.9
—
2.5
—
2.0-3.0
Step
NAT
1.2-1.7
0.2
0.9
None
0.17-0.48
LP
2.9-3.9
0.5
2.5
None
1.4-1.37
Table 7A. Pressure Regulator Specification Pressures (in. wc).
Table 7B. Pressure Regulator Specification Pressures (kPa).
•
Exposure to water, dirt, chemicals and heat can damage
the gas control and shut down the control system.
The maintenance program should include regular check-
out of the control as outlined in the Startup and Checkout
section, and the control system as described in the
appliance manufacturer literature.
Maintenance frequency must be determined individually
for each application. Some considerations are:
•
Cycling frequency. Appliances that may cycle 20,000
times annually should be checked monthly.
•
Intermittent use. Appliances that are used seasonally
should be checked before shutdown and again before
the next use.
•
Consequence of unexpected shutdown. Where the cost
of an unexpected shutdown would be high, the system
should be checked more often.
•
Dusty, wet, or corrosive environment. Since these
environments can cause the gas control to deteriorate
more rapidly, the system should be checked more often.
