Cleveland Convotherm Combination Oven-Steamer Gas 20.20 Service And Parts Manual page 54

◊ Every 120 seconds the rotation of the motor reverses.
◊ NOTE: If the temperature is less than 212 degrees F than fan will be
pulsed on for 2 seconds every 60 seconds after the cabinet set temp (B6)
and the bypass probe (B5) are satisfied.
c Hot air heat circuit is energized
• A signal is sent from terminal 2 of connector X24 on the Gas Board (A20) to
terminal 4 of connector X2 on the Upper Hot Air Power Burner and Fan
Control (U20) selecting the set speed of the combustion blower.
◊ When this speed is attained the signal is sent from terminal 2 of connector
X2 on the Upper Hot Air Power Burner and Fan Control (U20) to terminal
3 of connector X24 on the Gas Board (A20)
• A request for heat is sent from terminal 3 of connector X20 on the Gas Board
(A20) to terminal 10 on connector X1 on the Upper Hot Air Control Module
(N20)
◊ 24 VAC is sent from terminal 2 of connector X2 on the Upper Hot Air
Control Module (N20) to the hot surface igniter (R20).
◊ The gas valve is energized allowing gas and air into the burner chamber to
be ignited by the hot surface igniter.
◊ The Upper Hot Air Burner Control Module (N20) senses at least 1.5 micro
amps DC from the Flame sensor (P1) at terminal 3 of connector X2 and
sends a signal from terminal 2 of connector X1 to terminal 10 of connector
X25 on the Gas Board (A20)
d When the Upper Burner Assembly has proven flame, the Lower Hot Air heat
circuit is energized
• A signal is sent from terminal 8 of connector X24 on the Gas Board (A20) to
terminal 4 of connector X2 on the Lower Hot Air Power Burner and Fan
Control (U21) selecting the set speed of the combustion blower.
◊ When this speed is attained the signal is sent from terminal 2 of connector
X2 on the Hot Air Power Burner and Fan Control (U21) to terminal 8 of
connector X24 on the Gas Board (A20)
• A request for heat is sent from terminal 3 of connector X22 on the Gas Board
(A20) to terminal 10 on connector X1 on the Hot Air Control Module (N22)
◊ 24 VAC is sent from terminal 2 of connector X2 on the Hot Air Control
Module (N20) to the hot surface igniter (R20).
◊ The gas valve is energized allowing gas and air into the burner chamber to
be ignited by the hot surface igniter.
◊ The Hot Air Burner Control Module (N20) senses at least 1.5 micro amps
DC from the Flame sensor (P1) at terminal 3 of connector X2 and sends a
signal from terminal 2 of connector X1 to terminal 10 of connector X25
on the Gas Board (A20)
e The heat circuit will remain energized until the cabinet set temperature is reached
f When the condensate box is heated to 140 degrees F at the B3 probe, 120 VAC is
sent from terminal 5 of connector X12 to the condenser valve (Y1) until the
temperature drops.
g If the "Crisp and Tasty" mode is selected