Cleveland Convotherm OEB-20.20 Service And Parts Manual page 60

◊ The normally closed auxiliary contacts of K55.1, K55.2 and K56 open
preventing the K57 contactor from energizing.
• If the combi fan is in the reduced setting 220 VAC is sent from terminal 6 on
connector X11 through the normally closed auxiliary contacts of contactors
K55.1, K55.2 and K56 to the coil of contactor K57
◊ The K57 contactor closes
(a) 220 VAC is sent through the Q57.1 thermal overload to the motor and
the upper motor turns at a reduced speed.
(b) 220 VAC is sent through the Q57.2 thermal overload to the motor and
the lower motor turns at a reduced speed.
◊ The normally closed auxiliary contacts of K57 open preventing the K55
and K56 contactors from energizing.
• For the first 2 minutes 220 VAC is sent from terminal 4 on connector X11
through the normally closed auxiliary contacts of contactor K5 to the K50
contactor coil
◊ K50 contactor closes and the motor turns CW
◊ The normally closed auxiliary contacts on K50 open preventing the K5
contactor from energizing.
• For 15 seconds the motor is de-energized and allowed to coast.
• For the next 2 minutes 220 VAC is sent from terminal 3 on connector X11
through the normally closed auxiliary contacts of contactor K50 to the K5
contactor coil
◊ K5 contactor closes and the motor turns CCW
◊ The normally closed auxiliary contacts on K5 open preventing the K50
contactor from energizing.
• NOTE: If the door switch (S7) opens by the door opening, then the fan circuit
is de-energized. Then the motor will be pulsed in the opposite direction to
"break" the fan. This is to stop the fan quicker for the operator.
c The hot air heat circuit is energized
• 220 VAC is sent from terminal 3 of connector X12 on the Control Board
(A10) to the coil of Contactors K41 and K61 until the cabinet reaches the set
temperature as sensed at probe B6.
◊ The Contactors K41 and K61 close and he 220 VAC is sent to the outer
elements (E41 and E61)
• 220 VAC is sent from terminal 7 of connector X11 on the Control Board
(A10) to the coil of Contactors K42 and K62 until the cabinet reaches the set
temperature as sensed at probe B6.
◊ The Contactors K42 and K62 close and 220 VAC is sent to the inner
elements (E42 and E62)
◊ If the reduced power option is chosen then Contactors K42 and K62 are
not energized.
d The steam circuit is energized
• 220 VAC is sent from terminal 4 of connector X12 on the Control Board
(A10) to the coil of the Y3 solenoid allowing water to be thrown against the
element until the bypass probe (B5) senses 183 degrees F.