STERO SD3 Series, Service And Parts Manual

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The control board is programed to cause the booster
heater to turn on at the beginning of every rinse cycle
and turn off at the end of the cycle. This occurs even
if the booster water temperature meets or is above the
booster temperature set point. Should the booster
temperature be below the set-point, the booster
heater will remain energized until set-point is
achieved.
If the booster water temperature is below the booster
temperature set point at the end of a wash cycle, and
Rinse Assurance is enabled, the wash cycle will be
extended (maximum total wash time is one minute).
The extended wash time allows the booster water
temperature to reach set point before the rinse cycle
begins.
The tank float also controls the heat for the booster. If
the float is down (float switch open), the booster heater
circuit will be disabled. If the float is up (float switch
closed), the control board will regulate the booster
heat as needed.
READY MODE
When a cycle is not in progress, the machine will be
maintained in a ready state. In the ready state, tank
and booster temperatures are maintained. If water
level drops below the tank float in ready mode, tank
and booster heating elements are de-energized and a
fill cycle will be initiated the next time the chamber
door is opened and then closed. An error code [ Ed ]
will be displayed indicating the machine has a slow
leak. To clear an error from the display, cycle power
by turning the machine off then back on.
RUNNING A CYCLE
After the fill cycle is complete, a cycle is initiated by
raising and lowering the chamber door.
NOTE: If the chamber door is raised any time during
a cycle, the wash pump and rinse solenoid will
deenergize. The control will start a new cycle once the
chamber door is closed.
CHANGING CYCLE TIME
Changing Cycle Time
Wash cycle duration can be selected at any time
whether the machine is at rest or in a cycle. Pressing
the CYCLE button will step through the pre-
programmed timed cycle selections 1, 2, or 4. The
selected cycle time will be retained by the control even
when power is removed and turned back on.
Cycle selection 1 is programmable allowing the wash,
dwell, rinse, and sani-dwell times to be changed from
the default settings. Refer to SERVICE
PROGRAMMING for procedures on altering the pre-
programmed times of cycle one.
NOTE: Cycle 1's times cannot be adjusted below the
NSF minimums.
LUBRICATION
Component Lubrication Type
Impeller O - Ring P 80® Rubber Lube
Booster Heater Screws Never Seez
All NPT Fittings
Pipe Thread Sealant,
Locktite 565
High-Limit Thermostat
1TAS
Thermal-Joint Compound
High-Limit Thermostat
3TAS (Booster Option.)
Thermal-Joint Compound
TOOLS
• Standard set of hand tools.
• VOM with A/C current tester (any quality VOM
with a sensitivity of at least 20K ohms per volt can
be used).
• Anti Static Kit
• Temperature Tester.
• Clamp on type amp meter for meausring heating
element current draw.
SD3 Series - GENERAL
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