The H-3185B controller (Figure 1) uses on-off control of heating and cooling devices to
cycle between two temperatures. It can be set to cycle between two temperatures for a
finite number of cycles and then stop. When set to run for a finite number of cycles,
ramp rate between temperature extremes can be adjusted as well as soak duration at each
temperature extreme. The controller is programmed to cycle from 40°F to 0°F when set
to run in cycle mode. The controller is designed to be wall mounted near the
Freeze/Thaw machine and runs on 125VAC power. The controller also utilizes a
temperature chart recorder with circular chart paper for tracking and documenting the test
cycles. A J type thermocouple is also supplied with the controller.
1. Mount the controller box securely on a wall nearest to the Freeze/Thaw cabinet,
but away from water or extreme moisture.
2. Plug in all electrical devices on the cabinet such as heaters, cooling system
compressor, fan, and mechanical thermostat to the sockets at the bottom of the
controller box (Figure 2). All electrical connections have twist to lock plugs that
easily attach to the controller box. Each connection is different and no two
connections can be confused.
Figure 2
3. Open the door to the controller box and check the toggle switches inside the
controller box. If they are switched off as in Figure 3, switch heater, cooler, and
fan to the ON position.
4. Plug the main power cord from the controller box into an appropriate receptacle.
The controller requires a 125VAC, 30 amp power source.
5. Connect the thermocouple wire from the machine to the matching connector
coming from under the chart recorder.
6. The main circuit breaker is located on the side of the controller box near the door
latches. Set the breaker to the ON position.
7. Wait for the controller to go through its self test. When the self test is complete,
the upper red display and the lower green display will show temperature readings.
The green display is the set value and the red display is the actual temperature
reading from the TC (Figure 4).
The default mode for the controller is “Normal” mode. In this mode, the controller
will try to maintain the temperature controlled by the Set Value (green display).
When the controller receives power, it will automatically go to this mode. The
controller will continue to heat or cool to maintain the set value temperature until it is
manually stopped. To change the Set Value, press the up or down arrow button
and the value in the green display will change. The speed that the value in the
display changes is a function of the length of time the button is held down. The
longer the button is held down, the faster the display value will change.
3. Follow step 3 in section 4.1 to return to the temperature readings and begin the
operation.
Note: When in Normal mode operation, the controller will try to maintain the
temperature of the set value (green display). If it is desired to maintain the test
samples at a certain temperature, Normal mode should be used. If the controller
was on standby when power to the controller was disconnected and later
reconnected, the controller will automatically go into normal mode when it
receives power.
4.1.2 Standby Mode
1. To change to Standby mode, follow the step 1 in section 4.1 for changing the
ASTM C 666. The controller allows for up to 100 cycles in this mode. The
controller is set up to cycle down to 0°F and then up to 40°F for a total of 36
cycles. When the last cycle has been completed, the controller will automatically
go to standby mode.
5.0 Changing Ramp/Soak Cycle Settings
The settings in the cycle recipe can be changed to the user’s needs. The
temperature set points, ramp times, soak times, and number of cycles can be
changed by going into the recipe menu. One cycle can have up to eight
temperature set points. Each temperature set point has an associated ramp time to
reach that temperature set point and a soak time at that temperature. This
controller is preset to have two temperature set points in a cycle.
5.1 Setting Recipe Options
1. Press the Menu button on the front of the controller and hold it down for at
least three seconds until the display changes.
2. Press the Menu button again quickly to change the red display. It may be
necessary to press the Menu button several times until the red display reads “r-S”
(Figure 9).
1. Continuing from section 5.1, while the green display is alternating between
“rOPt” and “8.r.S” as in step 3 of the previous section, push the Mode button
again until the green display reads “HLd.b” (Figure 11). This is the
Holdback Band function. The green display will alternate between “HLd.b”
and the holdback set temperature variance.
Figure 11
Note: The Holdback Band changes the allowed temperature variance from the set
value. If the actual temperature goes beyond this variance during the cycle, the
ramp timer will stop and the controller will attempt to reach the set value
temperature by switching back and forth between heating and cooling until the set
value is reached before continuing. This setting is preset to 2° which is slightly
less than the 3° variance specified by the ASTM standard at the cycle extremes.
Increasing this setting could allow the test sample to exceed the allowed variance
at the cycle temperature extremes. Decreasing this setting could cause nonuniform cycling
Note: The Termination State tells the controller what to do at the end of the test. The
controller is preset to go to standby when the testing is complete.
1.
5.4 Setting Number of Cycles
1. Continuing from section 5.3, while the green display is alternating between
“tEr.S” and “Stby” as in the previous section, push the Mode button again
repeatedly until the green display reads “”rcY.n” (Figure 13). The green display
will alternate between “rcY.n” and the number of cycles desired minus one (i.e
for 36 total cycles, it should display 35).
Figure 13
2. To change the number of cycles, press the up or down arrow button
1. Continuing from section 5.4, while the green display is alternating between
rcY.n” and the set number of cycles as in the previous section, continue pressing
the Mode button until the green display reads “PFrE” (Figure 14). The
display will alternate between “PFrE” and “on”.
Figure 14
2. To change the option, press the up or down arrow button until the
option is displayed.
Note: This setting controls what happens when the power fails during a
cycling operation. The controller is preset to resume the cycling when power
returns. The options are “on” and “OFF”.
1. Continuing from section 5.5, while the green display is alternating between
“PFrE” and the set option as in the previous section, continue pressing the Mode
button until the green display reads “rt1” (Figure 15). The display will
alternate between “rt1” and the ramp time value (in minutes) for the first ramp in
the cycle. It is capable of 8 ramp operations in the cycle. This is the first ramp
time setting. The soak time and temperature for the first ramp must be
programmed or skipped before going to the next ramp time setting. It is preset to
5 minutes.
Figure 15
2. To change the ramp time, press the up or down arrow button until
the desired ramp time is achieved.
Note: Due to the thermal behavior of the Freeze/Thaw machine and the response
of the sample material, it is not recommended that this setting be increased as this
could cause fluctuations in the cycle ramp and greatly increase the overall cycle
time.
5.7 Setting Soak Temperatures
1. Continuing from section 5.6, while the green display is alternating between “rt1”
and the set ramp time value, continue pressing the Mode button until the
green display flashes “SL1” (Figure 16). The display will alternate between
“SL1” and the soak temperature value in degrees F. As in the case of the ramp
time, this is the first of 8 soak levels available. Soak level 1 is preset to 0.
Figure 16
2. To change the soak temperature, press the up or down arrow button
1. Continuing from section 5.7, while the green display is alternating between “SL1”
and the soak temperature, continue pressing the Mode button until the green
display flashes “St1” (Figure 17). The display will alternate between “St1” and
the soak time (in minutes). As in the case of the ramp time, this is the first of 8
soak times available. Soak time 1 is preset to 0 so that as soon as the temperature
reaches the set point, the controller switches to the next ramp to reach the next
temperature set point.
Figure 17
2. To change the soak time, press the up or down arrow button until
the desired time is achieved.
Note: It is necessary to set ramp time 1, soak level 1, and soak time 1 before
setting ramp 2 and soak 2. Simply continue pressing the Mode button until rt2,
SL2, and St2 appear in the green display. If no more temperature levels are
required in the cycle, return to the main operating mode by pressing and holding
down the Menu button until the red display reads the current temperature.
Ramp time 2 is preset to 5 minutes. Soak level 2 is preset to 40°F. Soak time 2 is
preset to 0. The remaining 6 ramp times are preset to 0. If the ramp time is set to
0, the ramp will be skipped.
6.0 Service
For any service issues, contact Humboldt Scientific, Inc. at 1-800-537-4183 between 8:00
AM and 5:00 PM Eastern Time.