Offset
In the event the refrigerator needs to be calibrated, a sim-
ple routine is available to adjust the display and control
point to a referenced standard. To set a temperature off-
set while in the Control Mode (mode LED off), simply
press and hold the Menu key for 5 seconds. The display
will flash oS followed by the last temperature offset value.
The factory setting is 0.0. To change the offset value,
press the Increase or Decrease keypad to the value
which when algebraically added to the last displayed tem-
perature, will agree with the reference temperature. Next,
press the Menu key until the Mode LED turns off.
For Example:
The display indicates 4°C but a reference thermometer in
the refrigerator chamber indicates 6°C. The operator
presses and holds the Menu KEY until the display shows
(oS) offset, then the value. Change the value from 0.0 to
2.0. The Menu key is then pressed repeatedly until the
Mode LED turns off. Now the display indicates a cham-
ber temperature of 6.0°C (approx.) and the controller
begins to cool to the desired temperature of 4.0°C.
Allow an additional 30 to 40 minutes for the refrigerator to
again stabilize. If the display is still inaccurate, repeat the
calibration procedure.
Convenience Outlet
(Chromatography Refrigerators Only)
Chromatography Refrigerators are equipped with a con-
venience outlet located in the center of the back wall.
Models 140A, 140RA, 141A AND 141RA (three doors)
have two convenience outlets. The power to the outlets
is protected by a circuit breaker. The breaker is located
just below and to the right of the outlet. Pressing the
breaker button resets the breaker after a fault.
The total load to one or both convenience outlets should
not exceed 4 amps.
21
C
ONTROLS
Caution
INCREASING the offset value
DECREASES the temperature at
which the system controls. If the offset
is inadvertently set too high, the cham-
ber temperature can fall below zero
and lead to evaporator freeze-up.
Warning
The convenience outlet is LIVE at
any time the unit is connected to an
electrical power source, regardless
of the position of the key switch.
