Operating Mode Definitions - Johnson Controls G77 Series Installation Sheets Manual

The following definitions describe operating conditions:
Operating
Mode
• Prepurge--Initial time delay between thermostat contact closure and
Definitions
• Trial for Ignition--Period during which the pilot valve and spark are
• Run--Pilot and main gas valves remain energized and spark is turned
• Shutoff--Pilot gas did not ignite within the trial-for-ignition time. The
• Automatic Recycle--If shutoff occurs, the control delays for a specific
• Interpurge--Period between trials for ignition when both the gas valve
• Ignition Lockout--Pilot gas did not ignite within the final
• Flameout--Loss of proven flame.
• Hard Lockout--The control detected a fault. Open thermostat contacts
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trial for ignition.
activated, attempting to ignite gas at the pilot burner. The control
attempts to prove flame at the pilot burner within the trial-for-ignition
time.
off after successful ignition.
control de-energizes the spark circuit and pilot valve, and enters
automatic recycle period.
recycle delay period before beginning another trial for ignition (models
with recycle only).
and spark are deactivated to allow unburned gas to escape before the
next trial. Interpurge occurs between unsuccessful trials on a multi-trial
control or after a flameout (if the control has an interpurge).
trial-for-ignition time. Open thermostat contacts for 30 seconds, then
close, to restart the sequence of operation. (Models with an optional
Light-Emitting Diode (LED) will flash the LED to indicate ignition
lockout.)
for 30 seconds, then close to restart the sequence of operation. (Models
with an optional LED will turn off the LED to indicate a hard lockout.)
GG77x Intermittent Pilot Ignition Controls Technical Bulletin 3