Owner`s manual

17
SECTION 5 FIELD SERVICE INSTRUCTIONS & ASSEMBLY
DOMESTIC
THE PRESSURE ACTUATED TEMPERATURE
CONTROL, STM-E AND STM-EL :
The pressure actuated temperature control, located
behind the control panel assembly, governs the manu-
facture of steam by controlling the input of electric cur-
rent to the heating elements.
HOW IT WORKS: When the Timer is set, rear and
front contactors will become energized allowing input
of current to the temperature control, thus closing the
contacts completing the current to the heating ele-
ments. Steam will then be generated within the steril-
izing chamber.
The steam pressure within the sterilizing chamber is
transmitted by means of a tube to the bellows of the
temperature control; as the steam pressure increases,
its compression action on the bellows is set to cause
the Switch #1 on the control to cut out on rising pres-
sure at 13.5 PSI and to cut in on falling pressure at
13 PSI (controlling the two outer banks of heating ele-
ments). Switch #2 is set to cut out on rising pressure at
15.5 PSI and cut in on falling pressure at approximately
15 PSI (controlling center heater element only).
Thus, a balancing effect of steam pressure build-up
and heater element current is constantly maintained
during the sterilizing cycle. When the Timer signies
the end of the cycle, the electric current to the con-
tactors will automatically be broken; the temperature
control contacts will be broken; and steam generation
will stop.
ADJUSTING THE RANGE OF OPERATION, STM-E:
NOTE: These instructions should be
performed by qualied service personnel only.
The operational range of the temperature control is fac-
tory set as follows: Outer bank of elements OFF at 13.0-
13.5 PSI; Center bank of elements OFF at 15.5- 15.0
PSI; minor compensating adjustments can be made by
turning the adjusting screws counter-clockwise to in-
crease pressure and clockwise to decrease pressure.
Both screws should be turned the same amount when
making an adjustment.
NOTE: When resetting this control for elevations above
sea level a correction of 6/10 Ib. per thousand feet is
necessary.
Before making adjustments, shut all electrical
current to the sterilizer OFF to eliminate shock
hazard.
Remove the Flue Cover.
Make sure that all exposed wires are not in a haz-
ardous position, and then turn on electrical power.
Run unit through cycle, observing pressure and
1.
2.
3.
4.
temperature gauges, turn adjusting screws as re-
quired.
EXPORT
THE PRESSURE ACTUATED TEMPERATURE
CONTROL, STM-EX AND STM-ELX:
The pressure actuated temperature control, located
behind the control panel assembly, governs the manu-
facture of steam by controlling the input of electric cur-
rent to the heating elements.
HOW IT WORKS: When the timer is set, rear and
front contactors will become energized allowing input
of current to the temperature control, thus closing the
contacts completing the current to the heating ele-
ments. Steam will then be generated within the steril-
izing chamber.
The steam pressure within the sterilizing chamber is
transmitted by means of a tube to the bellows of the
temperature control; as the steam pressure increases,
its compression action on the bellows causes the con-
tacts to make or break according to the condition of the
pressure at that time (rising or falling).
Switch #1 on the control is set to cut out on rising pres-
sure at 0.95 kg/cm
2
and to cut in on falling pressure at
0.91 kg/cm
2
(controlling the two outer banks of heating
elements). Switch #2 is set to cut out on rising pres-
sure at 1.09 kg/cm
2
and cut in on falling pressure at
approximately 1.05 kg/cm
2
(controlling center heater
element only).
Thus, a balancing effect of steam pressure build-up
and heater element current is constantly maintained
during the sterilizing cycle. When the Timer signies
the end of the cycle, the electric current to the contac-
tors will automatically be broken.
CHECKING THE 110°C. SETTING, STM-ELX:
The Unit should be completely evacuated then temper-
ature selector dial turned to 110
o
C Centigrade. Observe
the current until it takes a sharp drop to approximately
one-third of the full load; at this instant, there should be
a corresponding chamber pressure of 0.14 kg/cm
2
.