Safety Shutdown - resideo S8910U3000 Manuel D'installation

the main burner (burner ground). The S8910U flame
sensing circuit detects the flame current and holds open
the gas control. The main flame is monitored continuously
during the call for heat.

Safety Shutdown

One Trial
If flame is not sensed by the end of the timed trial for
ignition, the gas control closes and the module locks out.
It must be manually reset by removing power or setting
the thermostat below the room temperature for at least 30
seconds.
If the burner lights and flame is proved but goes out
during the run cycle, the gas control closes and the
module locks out. It must be manually reset by removing
power or setting the thermostat below the room
temperature for at least 30 seconds.
Three Trial
If flame is not sensed by the end of the first timed trial for
ignition, the gas control closes and the module initiates a
second 96 seconds between trial purge cycle, followed by
igniter warmup and a second trial for ignition. If flame is
not established, the between trial purge, warmup, trial for
ignition cycle is repeated a third time. If flame is still not
established following the third trial, the gas control closes
and the module locks out. It must be manually reset by
removing power or setting the thermostat below the room
temperature for at least 30 seconds.
If the burner goes out during the run cycle, the gas control
closes and the module checks for the number of ignition
trials performed during the current call for heat. If the
number is less than three, the module initiates a between
trial purge, warmup and trial for ignition. After the third
trial during a single call for heat, the module locks out. The
module must be manually reset following the lockout.
MAINTENANCE
WARNING
FIRE OR EXPLOSION HAZARD.
CAN CAUSE PROPERTY DAMAGE, SEVERE
INJURY, OR DEATH.
Do not attempt to take apart the module or to clean
it. Improper assembly and cleaning can cause
unreliable operation.
Regular preventive maintenance is important in
applications that place a heavy load on system controls
such as those used in the commercial cooking and
agricultural and industrial industries because:
• In many such applications, particularly commercial
cooking, the equipment operates 100,000 to 200,000
cycles per year. This heavy cycling can wear out the gas
control in one to two years.
• Exposure to water, dirt, chemicals and heat can
damage the gas control and shut down the control
system. A NEMA 4 enclosure can reduce exposure to
environmental contami-nants.
The maintenance program should include regular
checkout of the system as outlined in the Startup and
Checkout section, and checkout of 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. Because these
environments can cause the gas control to deteriorate
more rapidly, the system should be checked more often.
Any control should be replaced if it does not perform
properly on checkout or troubleshooting. In addition,
replace any module if it is wet or looks like it has ever been
wet. Protective enclosures, as described in the Planning
the Installation section, are recommended regardless of
checkout frequency.
TROUBLESHOOTING
IMPORTANT
1. The following service procedures are provided as a
general guide. Follow the appliance manufacturer
service instructions if available.
2. Meter readings between gas control and ignition
module must be taken within the trial for ignition
period. Once the ignition module shuts off, wait for
retry or reset at the thermostat.
3. If any component does not function properly,
make sure it is correctly installed and wired before
replacing it.
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S8910U3000
34-00008EFS—03