PRINCIPLES OF OPERATION
11
INDICATOR LIGHTS:
An indicator light is included for both compartments.
The light remains on (red) at all times when the co-
inciding timer dial is set and the door interlock switch
is closed. The light turns off at the end of the timed
cooking duration.
BUZZER:
The buzzer is an alarm device that operates by oscil-
lation of a striker against the core of an electromag-
net. When the 60 minute timer dials reach the “0 Min-
ute” position, the buzzer coil is energized to sound
the buzzer. Movement of the timer dial to the OFF
position opens the contact to the buzzer coil to shut
it off.
DOOR INTERLOCK SWITCH:
The interlock switch is a single-pole proximity switch
with normally open contacts. The switch is operated
by the proximity of a magnet within the door. When
the door is open, the switch contacts remain in the
open position. When the door is closed and secure-
ly latched in place, the magnet is near the switch to
close the contacts. Connected between the operating
contact (3) of the timers and the steam inlet solenoid
valve, the door switch acts as a protective device to
interrupt valve operation unless the door is closed.
THERMOSTATIC SWITCH:
The thermostatically operated switch is a two-posi-
tion, normally open switch mounted on the cooking
compartment. The switch functions to activate the
cold water solenoid valves of the steam condensing
system and to delay timer motor operation until the
compartment temperature reaches 195°F, thus as-
suring that cooking temperature exists throughout the
timed duration.
Fig. 2 Pictorial Diagram, Steam and Water Circuits
