Fisher Scientific 146E, Quick Start Manual, Page: 3 / 6

2. To display the setpoint temperature, press the SET key.
The setpoint temperature will remain on the display for 1
sec. after the SET key is released.
3. To change the setpoint temperature, press and hold SET
while pressing the
∆
or
∇
keys to change the setting. (Note
that when either
∆
or
∇
keys are first pressed, the display
will begin to change slowly at first, then increase change
rate after a few seconds.)
4. Select the desired chamber setpoint then release all
keys. The controller display will revert back to actual
chamber temperature after a few seconds. Allow up to an
hour for unit to stabilize at the new setpoint temperature.
After the incubator temperature has stabilized, place
samples into incubator chamber. For best results, arrange
samples evenly throughout the chamber. Liquid samples
should be covered to prevent evaporation and eventual
frost build up on evaporator coils, particularly when
operating below ambient. Note that frost build-up is normal
when unit is being operated below 35
°
C with cooling set to
100% mode.
The Low Temperature Incubator has an internal 2 amp.
convenience outlet inside chamber to operate devices such
as: shakers, rotators, photosynthesis lights, recording
thermometers etc.
Accessing Controller Menus:
The temperature controller has three menu selections that
can be accessed by pressing and holding the MENU key for
3 sec. To access menu parameter, press and hold the SET
key. To change the parameter, use the
∆
or
∇
keys.
CAL Menu - Calibration Menu is used to change the
temperature offset value to correct for differences in
chamber temperature and the displayed temperature.
Range -5
°
to 5
°
C. See Calibration Procedure.
Pct Menu - (Percent Cooling Menu) Used to select one of
three cooling modes:
100% Mode- Compressor runs continuously which provides
high precision control (+/-.2
°
C Stability) over entire
temperature range. Requires manual defrost.
50% Mode- Compressor runs approximately half the time,
which conserves power and also reduces the amount of
frost buildup on the evaporator. This method greatly
reduces the frequency of manual defrosting but provides
less temperature stability (+/- 1.5°C).
00% Mode- Compressor is completely off. This mode is
ideal for incubating samples at temperatures 10
°
C or higher
above ambient (35
°
C to 60
°
C). It provides the greatest
power savings yet still maintain the advertised stability. No
defrosting required.
Pro Menu - Protection Menu - Used to select the Protection
mode of operation that determines when the alarm is
activated and if the control setpoint can be changed.
Range 0.0 to 0.2.
0.0 Mode- Normal mode that allows the user to change
setpoint. Alarm activates if chamber temperature
(chamber) and setpoint temperature (setpoint) are as
follows:
chamber
≤
15.0
°
C and chamber < (setpoint - 3) or
chamber
≥
40.0
°
C and chamber > (s3)
While ALARM is activated, the safety relay is opened
interrupting power to the heater, fan, convenience outlet
and compressor. When chamber temperature returns to
acceptable limits, the ALARM will automatically terminate
and power is reapplied. In order to allow changing of
setpoint and eliminate nuisance alarms, an alarm by-pass
takes effect when the setpoint is changed or when power is
first applied. The alarm by-pass works as follows: Present
chamber temperature is stored as a nominal alarm
temperature (nominal). If chamber < setpoint then alarm
temperature (alarm) = nominal -3. If chamber > setpoint
then alarm = n3. If chamber should go beyond
alarm or < -13 or > 63 then the ALARM will activate. This
alarm by-pass is active until chamber reaches setpoint
±1
°
C.
0.1 Mode- Same as 0.0 Mode, except that the setpoint is
locked and can't be changed.
0.2 Mode Setpoint is locked, plus, the ALARM will activate
and the safety relay will open as follows:
chamber < (setpoint -3) or chamber > (se3)
In order to use this mode of protection, modes 0.0 or 0.1 will
have to be used to reach the setpoint temperature. Once
the chamber temperature reaches the setpoint and is
stable, protection mode 0.2 can be set.
Note! If the chamber temperature falls outside the setpoint
by ±3
°
C, the ALARM will activate and safety relay will
interrupt power. This mode can only be used if the door is
to remain shut and other disturbances don't effect the
chamber temperature.
As an added safety feature, the incubator has a thermostat
in the heater compartment that limits the upper chamber
temperature to 65
°
C.
MAINTENANCE
WARNING
To reduce the risk of electric shock, disconnect from
power source before servicing.
Before re-applying power, after maintenance is complete,
check to ensure that safety ground is intact and making a
good connection.