G—G770BGJ 100% Lockout, Microprocessor-Based Intermittent Pilot Ignition Control 3
The G770BGJ ignition control is designed to ignite gas at the pilot burner
through the use of a spark. An electrode is positioned in the pilot gas
stream and adjusted to provide a nominal spark gap of 2.54 mm (0.10 in.).
The pilot burner then ignites the main burner.
The G770BGJ control proves the presence of the pilot flame by flame
rectification, and automatically shuts off the gas supply to the pilot burner
and the main burner if the pilot flame does not prove.
All applications must use redundant gas valves. This control is suitable for
operation over a temperature range of -40 to 71
°
C (-40 to
160°
F). Any
application over 117 kW (400,000 Btu/hr) must be approved by the
Johnson Controls Application Engineering Department.
The following definitions describe operating conditions:
•
Prepurge--Initial time delay between thermostat contact closure and
activation of the spark circuit and pilot valve.
•
Trial for Ignition--Total time pilot valve and spark circuit energize in
an attempt to light the pilot.
•
Run--Main valve energizes and spark turns off after pilot flame is
proven. Main burner remains on until thermostat contacts open.
•
Interpurge--Period between trials for ignition when both gas valve
and spark are deactivated to allow unburned gas to escape before the
next ignition sequence. Interpurge occurs only if ignition was not
successful during the previous trial or after a flameout.
•
Flameout--Loss of proven flame.
•
Lockout--An internal or external fault that causes the control to
de-energize the spark circuit and gas valves. The thermostat contacts
must be opened for 30 seconds and then closed to begin a trial for
ignition.
Application
Operating Mode
Definitions