Cooler Program - Hach BioTector B3500e User Manual

8.3.11

Cooler Program

MODE
BACKUP PWM DUTY
50% PWM OFFSET
50% PWM SLOPE
T DIFFERENCE
T CONTROL
10%
14.0C
5.00%/C
16.0C
 MODE defines the operation mode of the Cooler. Cooler
operates automatically with the default TEMPERATURE
CONTROL setting, to achieve the programmed TEMPERATURE
DIFFERENCE below.
 When MODE is programmed as PWM "PULSE WIDTH
MODULATION", the Cooler operates using the BACKUP PWM
DUTY setting below.
 BACKUP PULSE WIDTH MODULATION DUTY defines the
operation of the cooler in back-up mode, i.e. when there is a
fault with the Cooler or with the BioTector temperature sensor
(i.e. when system generates 107_COOLER FAULT and/or
108_COOLER FAN FAULT or 113_TEMP SENSOR FAULT
warning events). The default 10% setting means that the Cooler
is activated for 10% of the time and deactivated for 90% of the
time.
 The BACKUP PWM DUTY mode is automatically cancelled
when the relevant faults are acknowledged in the Fault Archive
menu.
 The 50% PWM OFFSET setting (14°C by default) is the
midpoint offset of the cooler temperature calibration curve, which
is linear. When Cooler operates with PULSE WIDTH
MODULATION at 50%, the Cooler temperature is typically
~14°C below ambient temperature, which is ~25°.
 The 50% PWM slope setting (5% per 1°C by default) is the
slope of the cooler temperature calibration curve at midpoint.
When Cooler operates with PULSE WIDTH MODULATION at
50%, the Cooler temperature changes by ~1°C with every 5%
change in PULSE WIDTH MODULATION.
 TEMPERATURE DIFFERENCE (16°C by default) defines the
temperature difference to be achieved between the BioTector
temperature and the Cooler temperature. BioTector temperature
sensor is located on the O2-Controller Board. Cooler
temperature is achieved with the settings described above.
 Cooler Temperature
TEMPERATURE DIFFERENCE.
 When BioTector detects that the Cooler temperature will drop
below 5°C applying above settings, system automatically
decreases the PULSE WIDTH MODULATION so that the
temperature of the Cooler does not drop below 5°C. This is
carried out to avoid possible freezing of the condensate water,
which could be present inside the Cooler.
= BioTector Temperature –
Page 129