VWR VWRC0386A, Instruction Manual

Page: 50 / 94

Each blink will take one second, with half of the second interval being
ON (illuminated) and the other half of the second interval being OFF.
After the sequence concludes, both the Low Battery LED and the
Solenoid Engaged LED will flash four times ON/OFF quickly to
indicate a return to normal display.
3. 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 200C below BUS set point and it is determined
to be a valid input, then injection will terminate immediately.
4. 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.
s
Caution
.The back-up system is designed to inject refrigerant (CO
2
or
LN
2
). In the unlikely event of both probes failing, the back-up system will
operate in PWM or Non-PWM mode based on jumper setting (Figure 7-
7)
s
For Hysteresis & Dual probe fault mode settings (Figure 7-7), locate
Jumper J17 near to solenoid/ sensor connector (J1), refer to table below for
operation details:
7-6 Chest Freezer VWR International
Section 7
Factory Installed Options
Jumper PIN Status Hysteresis Dual Probe Fault Mode
J17 PIN 1 & PIN 2 Short Together/ Jumper Cap Installed 5°C Non-PWM Mode
J17 PIN 1 & PIN 2 Open/No-Jumper Installed 9°C PWM Mode
Table 7-2. Probe Fault Modes
BUS Control Panel
(cont)