AEC VacTrac Series Conveying Systems - Manual (Page 79)

VacTrac™ Series Conveying Systems Page 79
Mechanical Components WH2-605A.4
4 Component Operation
4-1 Vacuum Switch (VS) Operation
A high vacuum switch is mounted inside a VacTrac pump package
junction box. It is preset to close at 14” Hg (475 millibars) and is
not adjustable. The vacuum switch protects the pump package
from motor damage caused by high amperage draw and strain on
the blower.
Pumps typically draw a vacuum of less than 5” Hg (170 millibars)
only when air is pulled into the system and 8” to 12” Hg (271 to
339 millibars) while conveying.
If system vacuum should reach 14” Hg (475 millibars), the high
vacuum switch closes. The pump package tries to clear the line for
three seconds, then moves to the next on-line vacuum receiver. The
normal conveying cycle continues. If high vacuum keeps
occurring, the pump continues with attempts to clear the line.
Refer to your AEC VacTrac controller manual for more
information.
4-2 High Vacuum Relief Regulator Operation
A factory-set pressure regulator is installed on the pump package
vent valve as a mechanical back-up safety feature. It protects the
pump motor from damage during high vacuum conditions if an
undetected failure of the vacuum switch should occur. The
regulator is set to limit system vacuum to 15” Hg (475 millibars)
by allowing the vent valve plunger to shift and vent the pump.
Important!
Do not adjust the pressure regulator.
Adjusting the pressure regulator voids your VacTrac warranty.