Southbend StratoSteam STRE-5D - Manual (Page 20)

S ERVICE S TRATO S TEAM E LECTRIC C OUNTERTOP S TEAMER
P AGE 20 OF 56 O WNER ’ S M ANUAL 1189951 (10/08)
H OW THE S TEAMER O PERATES
Compared to steam cookers that have complicated boilers, a StratoSteam steamer is a very simple machine. The
heating cartridges are integrated into the bottom plate of the cooking cavity, and begin to heat immediately as soon as
the steamer is turned on. As water flows into the cooking cavity it covers the heated bottom plate and is converted to
steam. There is no pressure in the steamer. From a cold start the steamer (in COOK MODE) will heat up to cooking
temperature in about 4 minutes.
The internal components of the steamer are shown in Figure 10 on the next page.
Turning the control lever to ON mechanically actuates the power switch, and so turns on power to the rest of the
circuitry. The “Power” indicator light comes on. Turning the control lever to ON also mechanically closes the cooking-
cavity drain valve.
The heating cartridges are controlled by a contactor. The contactor is energized (turning on the heating cartridges) if
(1) the door is shut (as sensed by the door switch), (2) the steamer is not overheated (as sensed by the high-limit
thermostats), and (3) if there is water in the bottom of the steamer cavity (as sensed by the water-level-control sensor
under the cavity). However, if the Cook-Idle switch is in IDLE MODE, the heating cartridges will heat only when the
Idle Thermostat is closed.
The flow of water into the cooking cavity is controlled by the water solenoid, which is energized (turning on the water)
when the control lever is turned to ON and the door is shut. Hence, when cooking, water flows continuously into the
cooking cavity. However, if the Cook-Idle switch is set to IDLE MODE, water will not enter the cavity.
If a high-level thermostat detects that the steamer is overheating, or if the water-level-control sensor (which is a
thermostat) detects low water (by sensing overheating), the contactor is de-energized (turning off the heating
cartridges). Overheating may be caused by too little water entering the cavity, or by lime buildup inside the cavity
reducing the conduction of heat to the water.
During operation, excess heated water flows into the drain box where it mixes with a small stream of cold water that is
continuously supplied to the drain box (to prevent the draining water from being too hot for the plumbing pipes). Water
drains from the drain box out the water drain on the rear of the steamer. If the drain is clogged, water backing-up into
the drain box will escape through the drain-box overflow vent on the rear of the steamer.
Any excess steam is vented out the pressure-relief valve located at the top left rear corner of the steamer.
The dial thermometer on the control panel is connected by a capillary tube to a sensor bulb located in the pressure-
relief vent. The thermometer does not affect the operation of the steamer.
A mechanical timer activates a buzzer when the timer times out. The timer does not affect anything else!
When the control valve is turned to OFF, power to the electric circuitry is turned off, which de-energizes the contactor
and so shuts off the heating cartridges. Turning the control lever to OFF also de-energizes the water solenoid (turning
off the water) and mechanically opens the drain valve, permitting all water to drain from the bottom of the cooking
cavity.