Honeywell ACM 150 Manual To Installation, Operation, And Maintenance page 25

ACM 150
Figure 12. Mechanical pump assembly
The Backup Exhaust Pump is an oil-less carbon vane vacuum pump with a high
flow capacity. If air is supplied to the venturi pumps and they are operating properly,
this pump is inactive. Insufficient vacuum, when detected by an absolute pressure
transducer, automatically applies power to the pump. The backup pump turns on
for both venturi pumps under these conditions. When the air supply is restored or
the problems are corrected, the user manually switches the ACM 150 monitor from
the automatic mode into the manual mode and back to automatic mode, using the
Diagnostic menu to use the venturi pumps again.
The Boost Pump speeds up the sampling cycle. It is a dual head diaphragm pump
with Teflon coated internal parts. It is always on. In the surge and fill cycles, the
boost pump provides a high rate of sample flow into the gas cell. In the evacuation
and analyze cycles, it keeps the sampled air flowing to bypass.
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