C24EO SERIES STEAMER - ELECTRICAL OPERATION

SEQUENCE OF OPERATION

Schematic diagram AI2851 will be used to explain the electrical sequence of operation.

Timed Cooking Mode

1.Conditions.

A.Steamer connected to correct voltage and is properly grounded.

B.Power switch (1S) off.

1)Relay K3 energized. K3 N.C. contacts open.

C.High limit thermostat closed.

D.Hold thermostat closed.

E.Low water thermostat closed.

F.Temperature control is setup properly and is ready to use.

G.Door closed (door switch closed).

H.Timer off.

I.Cooking compartment filled to the water level mark and below hold temperature of 175°F (+/- 5°F).

J.Drain valve is closed (drain lever pushed in).

2.Press momentary start switch (1S).

A.Limiting contactor (1CON) coil energized thru high limit thermostat (1TAS).

1)Line voltage is supplied to one side of heating elements.

B.Relay K2 coil energized thru low water thermostat (2TAS).

1)K2-1 N.O. contacts close.

a.Power switch circuit is latched.

2)K2-2 N.C. contacts open.

a.Low water light (1LT) and buzzer are de-energized.

C.ON indicator light (2LT, amber) comes on.

D.Relay K1 coil energized thru door switch and hold thermostat (3TAS).

1)K1-3 N.O. contacts close and regulating contactor (2CON) coil is energized.

a.Line voltage is supplied to other side of heating elements. Elements heat.

2)K1-2 N.C. contacts open.

3)K1-1 N.C. contacts open (prevents timer from being energized during pre- heat).

3.Steamer reaches 175°F.

A.Hold thermostat opens and relay K1 coil is de-energized.

1)K1-3 N.O. contacts close and remove line voltage to heating element assembly.

2)K1-1 and K1-2 N.C. contacts return to close condition.

NOTE: Steamer will maintain hold temperature until a cook time is dialed on timer, door is opened, or power switch is turned off.

4.Set cook timer to desired time.

NOTE: Timer motor will not run when hold thermostat (3TAS) is below 175°F.

A.Timer contacts close, timer motor is energized and timing down begins.

NOTE: Additional time can be set or the cook timer can be turned off throughout the cooking cycle. If turned to off, steamer reverts to hold temperature.

B.Cook light (3LT, red) comes on.

C.Temperature controller energized and evaluates input from thermocouple.

1)If temperature is below set point, temperature controller internal N.O. contacts close and energize regulating contactor (2CON) coil thru K1-2 N.C. contacts.

a.Line voltage is supplied to other side of heating elements. Elements heat.

5.Temperature reaches set point and the temperature control’s internal N.O. contacts open.

A.Regulating contactor (2CON) coil de- energized and power is removed from heating elements.

6.Steamer cycles on the temperature control until cook time expires.

7.Time expires on cook timer.

A.Timer contacts 11 & 13 open, timer motor is de-energized and timing stops.

B.Timer contacts 11 & 14 close.

1)Buzzer energized thru K2 N.O. contacts and sounds.

NOTE: The buzzer continues to sound until timer dial is set to off position or additional time is set.

C.Timer contacts 21 & 23 open, cook light (3LT, red) goes out and temperature controller is de-energized.

F25386 (June 2010)

 

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