Dräger PSS BG 4 plus

26 Dräger PSS BG 4 plus
Maintenance
4.5.1 Preparation of test
1. Switch on the test unit: Press the button for 3 seconds.
2. Position the closed-circuit breathing apparatus and test
unit so that both devices are easily accessible and the test
unit can easily be operated.
3. Remove the protective cover (see chapter 3.3.1 on
page 10).
4.5.2 Checking the response threshold of the low
pressure warning
1. Remove the protective cap from the connecting piece and
insert the connecting piece into the connection for the
closed-circuit breathing apparatus.
2. Set the selector switch on the test unit to .
3. Pump slowly.
4. Watch the test unit display:
The low pressure warning must activate before a pressure
of +1.4 mbar is reached.
The low pressure warning is displayed as follows:
 The backlight turns on including red LEDs.
 The "Open cylinder valve" symbol appears on the Sentinel
display.
 The alarm tone sounds intermittently.
4.5.3 Checking the inhalation valve
1. Tightly pinch the exhalation hose with your hand. Use the
face spanner from the test set if required.
2. Carry out pumping. The test unit must display at least
+10 mbar.
3. If +10 mbar is not reached, replace the inhalation valve or
inhalation valve disk (see chapter 4.2.3 on page 17).
4.5.4 Checking the exhalation valve
1. Set the selector switch on the test unit to .
2. Tightly pinch the inhalation hose with your hand. Use the
face spanner from the test set if required.
3. Carry out pumping. The test unit must display at least
-10 mbar.
4. If -10 mbar is not reached, replace the exhalation valve or
exhalation valve disk (see chapter 4.2.3 on page 17).
4.5.5 Checking the drain valve
1. Set the selector switch on the test unit to .
2. Put the open side of the protective cap over the pressure
relief valve tappet and hold. Pump until the protective cap
is secured by the filled breathing bag.
3. Continue to pump until flow noises can be heard at the
drain valve. Read the value on the display.
The drain valve must open between +15 mbar and +25 mbar.
NOTICE
The low-pressure warning generated by the Sentinel
during this test is irrelevant here.
OK
35021851.eps
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NOTICE
The low-pressure warning generated by the Sentinel
during this test is irrelevant here.
NOTICE
The low-pressure warning generated by the Sentinel
during this test is irrelevant here.
35221851.eps
L/min
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35121851.eps
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Page 26
Draeger Training 11/16 rev 1