AEC 1-Pump 1-Station Controller - Manual (Page 17)

1 –Pump 1-Station Controller Chapter 3: Installation 16 of 30
Using and Adjusting the Auto-Shutdown Timer (1TMR)
The Auto-Shutdown timer in the control enclosure is factory-set to shut down the vacuum
pump package if no material demand is sensed within approximately thirty (30) seconds. A
no-material-demand condition occurs if the bin-full sensor on the material receiver trips. The
timer starts at the beginning of the dump-delay sequence. Automatic operation resumes when
the material level drops in the machine bin or silo below the material receiver and creates a
material demand condition.
You can adjust the Auto-Shutdown timer between 0 and 100 seconds. To change the timer
setting, locate 1TMR in the control enclosure. Turn the knob clockwise (within the 270°
range) to increase the time period that the pump package remains on after the controller
senses a no-material-demand condition. Turn the knob counterclockwise to decrease this
time.
Note: The thirty-second (30 sec.) setting is ideal for most conditions.
Vacuum Switch Operation (1VS)
The vacuum switch is mounted in the pump package junction box. It protects the motor and
pump from damaging high vacuum conditions.
Note: The vacuum switch is preset at the factory for the maximum capacity of the
motor and pump, and must not be adjusted!
Allowing the vacuum switch to be tampered with voids your warranty!
During operation, the power unit draws a vacuum of less than 5” Hg (169 millibars) when
only air is pulled into the system; it draws a vacuum of 5” to 10” Hg (169 to 339 millibars)
when material conveys. If the vacuum reaches 12” Hg (407 millibars), it indicates an
obstruction in the system. The vacuum switch closes and a dump delay sequence starts. This
sequence repeats until you clear the obstruction.
Note: Vacuum draw depends on pump size.
Mechanical High Vacuum Relief
The regulated vent valve provides a backup mechanical safety that protects the system from
damaging high vacuum conditions if the vacuum switch fails. It prevents vacuum from
exceeding 14” Hg (475 millibars) by regulating the supply air pressure to the vacuum air
cylinder.
Caution! Do not adjust the air regulator on the vent valve to trip at a point higher
than 14” Hg (475 millibars).
This point is the maximum safe vacuum that the pump package can
operate.