Thermo Scientific TSC Series User Manual page 46

Section 6
Factory Installed Options
BUS Control Panel
(continued)
Figure 6-7. Jumper Cap for Hysteresis & Dual Probe Fault Mode Selection
6-6 TSC Series
BUS Injection Test
The user must press and hold the Press-to-Test button for >= 2 seconds
before injection occurs. After the Press-to-Test button is pressed for >30
seconds, the solenoid will turn off. This will avoid a button or button
signal becoming stuck in an active condition.
During a Press-to-Test injection, if either RTD #1 or RTD #2 reads a
temperature less than 20 C below BUS set point and it is determined to
be a valid input, then injection will terminate immediately.
BUS Set point "Validation" Feedback
Whenever the BUS set point or working fluid changes, the BUS
acknowledges the set point acceptance by causing the Low Battery LED
and Solenoid Engaged LED to blink three times ON/OFF quickly. This
does not imply that the BUS error-checked the values, other than that
the value received was within the range of the BUS working correctly
with prior programming.
Note The solenoid will not engage if lid is open.
Caution The back-up system is designed to inject refrigerant (CO
In the unlikely event of both probes failing, the back-up system will operate
in PWM or Non-PWM mode based on jumper setting .
Note PWM mode: If both probes fail, the solenoid will activate peridically,
allowing the flow of refrigerant (CO2 or LN2).
Non-PWM mode: If both probes fail, the solenoid remains OFF and no
refrigerant will flow.
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