Accu-Steam™ G2 Gas Service Manual
PAGE 8
SP8042-1609
Sequence of Operation
1. When the G2 griddle is plugged in, AC line voltage is supplied to the primary side of the
transformer.
2. The voltage out of the secondary side of the transformer is 24VAC nominal. Yellow and blue
wires out of the transformer.
3. The blue leg of the secondary side of the transformer (24VAC) is connected to the yellow
system harness, is split and is connected to the combination gas valve coils, remote timer connector
and the Hi-Limit thermostat.
4. From the HI-Limit thermostat the 24VAC leg is daisy chained to the, heat lamp, the main
digital control board and to chassis ground.
5. The yellow secondary leg of power from the transformer connects to the violet system
harness and goes to the Hi-Limit, then daisy chains over to the main digital control board. At this
time the system is waiting to be powered on via the Digital control board.
6. Upon pressing the “ON” button on the digital controller, the digital controller powers up and
a relay on the digital controller is closed making a connection between the violet 24VAC leg and
the input of the HI-Limit thermostat through the white with brown striped harness.
7. If the reading from the Hi-Limit RTD (Resistive Thermal Device) is not 425°F or higher, an
output relay in the Hi-Limit controller will be closed causing the 24VAC to be sent to the ignition
control, DC relay and to the pilot valve coil of the gas combination valve, opening the pilot valve.
8. If the reading from the Hi-Limit RTD (Resistive Thermal Device) is 425°F or higher, an
output relay in the Hi-Limit controller will be opened causing the 24VAC to be cut off from the
ignition control, DC relay and to the pilot valve coil of the gas combination valve, closing the pilot
valve.
9. The over temperature lamp is connected across the common and the normally open contacts
of the High Limit thermostat output relay. When the relay is activated or closed, the griddle
temperature is below 425°F, there is 24VAC on both sides of the over temp lamp, preventing it
from lighting up. If the High Limit thermostat output relay is deactivated or open, the griddle
temperature is at or above 425°F, the lamp will see the voltage potential from the chassis ground/
yellow system harness side of the transformer through the pilot valve coil and light up.
10. If the digital controller senses the griddle temperature is below the set point temperature via
the digital controller RTD sensor, the controller will output 24VDC to the ignition control DC coil
relay and allow 24VAC to be sent to the ignition module via the blue harness to pin 2 of the ignition
module, which is daisy chained to the ignition fault indicator lamp.
11. The ignition module will begin the ignition sequence by initiating a spark at the ignition probe
first then it will send 24VAC, via the red harness from pin #1 of the ignition module to the heat
lamp, which is daisy chained to the main gas valve coil of the combination gas valve through the
red system harness. This allows gas to flow through the combination gas valve, through the orifices
in each main burner and through the main burner tiles.
12. When the gas air mixture is ignited, the flame sense probe will detect a DC voltage level
through the flame’s ionized gas to ground via the orange flame sense harness to the ignition
module, pin #6.
