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3.3 Safety Features
The following safety features are incorporated as standard in the BAC-4015 and must not be disconnected, removed, or bypassed in any
manner.
3.3.1 Audible warning of system failure
If the BAC-4015 is depressurised without the operator's knowledge (e.g. compressor failure or system pressure loss), a warning whistle will
sound when the pressure drops to below 4 bar g (58 psi g) (minimum operating pressure).
3.3.2 Flow limiting orifice
This device limits the outlet flow rate proportionally to the line pressure thus ensuring that the volumetric air flow rate of the BAC-4015 is not
exceeded. The flow limiting orifice is located immediately after the outlet pressure regulator.
3.3.3 Hours run meter
The meter gives a visual indication of the operating hours of the BAC-4015.
When pressure to the purifier is established an internal pressure switch closes, operating the meter. The decimal point on the display blinks
when the meter is working. When pressure is removed from the Breathing Air Purifier the meter stops (see ‘Hours Run Meter Schematic’).
The hours run meter is battery operated with an expected 10 year life (not guaranteed). A knock out panel is provided on the facia of the cabinet
to accept the meter. An internal rail is also located behind this panel to house the pressure switch. Air supply to this pressure switch should be
taken from the cam timer motor inlet via a ‘Y’ connector (not supplied).
The fault must be identified and rectified before the equipment is used again.
3
1
2
2 (N)
HOURS RUN METER
PRESSURE SWITCH
TO AIR MONITOR INLET VIA Y-CONECTOR
1 (L)
