Loctite AC988557 - Manual (Page 17)

Page Number - 17
Setting the Pump Stop Trip
Speed
Pump Stop Operation
Selecting a speed range letter other than R,
will activate the Pump Stop, as discussed
earlier. The Pump Stop will “Trip”, stopping
the air motor from operating, if the threshold
speed setting is exceeded. The air motor
will not restart until it is intentionally reset.
The cause of a pump OVERRUN may be
anything that will allow the pump to run
faster than normal such as, but not limited
to the following.
Cavitation: Low fluid levels will allow the
pump to cavitate, where the pump is trying
to pump air instead of fluid into the fluid
lines.
Broken Hose or Fitting: will cause a loss
in fluid pressure allowing the pump to run
faster than normal.
Increase in Air Pressure: Either sudden
or gradual, may cause a pump operating
from an air supply system which is marginal
or inadequate for the application, to rise as
other equipment in the plant is shut down,
thus making more air available to the pump
to operate with. Unauthorized tampering
with an air pressure regulator may also be
a cause.
Increase in Demand: Fluid demand may
be greater than expected.
A tripped condition can be determined if the
air motor has stopped, the RED/ORANGE
indicator pin will be out (see Illustration 2),
the pump rod will be in the down position
and air will be heard venting from the VENT
HOLE in the lower body of the Pump Stop.
(See Illustration 4)
Before resetting, the cause of the OVER-
RUN should be determined if possible
before restarting the pump. Check for low
Illustration 2
pump by counting the number of strokes
the pump makes per minute.
4. After determining the normal operating
speed of the pump and air motor,
consult the Setting legend on the face
of the Labyrinth cover (item 78), and
find the speed range that is closest to
the normal operating speed of the air
motor.
5. To allow for normal fluctuation in the
operating speed of the air motor and
pump, set the selector knob to the next
highest speed setting.
6. Test the pump in operation to make sure
that it is operating normally before
leaving the pumping system unattended.
Speed Settings:
R Run mode, Pump Stop is disabled. Air
motor will continue to run at any speed.
A 35 to 45 Cycles per Minute, Pump Stop
will trip turning off the air motor when
the air motor speed reaches a speed of
35 to 45 cycles per minute.
B 25 to 35 Cycles per Minute, Pump Stop
will trip turning off the air motor when
the air motor speed reaches a speed of
25 to 35 cycles per minute.
C 20 to 30 Cycles per Minute, Pump Stop
will trip turning off the air motor when
the air motor speed reaches a speed of
20 to 30 cycles per minute.
D 15 to 25 Cycles per Minute, Pump Stop
will trip turning off the air motor when
the air motor speed reaches a speed of
15 to 25 cycles per minute.
E 10 to 20 Cycles per Minute, Pump Stop
will trip turning off the air motor when
the air motor speed reaches a speed of
10 to 20 cycles per minute.
F 5 to 15 Cycles per Minute, Pump Stop will
trip turning off the air motor when the air
motor speed reaches a speed of 5 to 15
cycles per minute.
Note: These speed settings are not
precision speed control settings for
the air motor. All speed settings are
approximate and are not intended for
use in precisely controlling the speed
of a pump/pump tube combination.
Precision control of the pump
operating speed is beyond the scope
of this device.
1. Remove the selector cover (item 87) by
removing screw (item 88) to gain access
to the selector knob (item 84).
2. Select the RUN mode by positioning the
selector knob pointer (a small round hole
in the face of the selector knob) to the
letter R on the face of the labyrinth
cover (item 78).
3. With the pump and air motor operating
normally, determine the speed of the
fluid levels, broken hose or fitting connec-
tions before restarting. If a cause cannot
be determined without starting the pump the
pump may be cautiously restarted and
observed for any indications of a problem
before resuming normal operation.
Resetting the Pump Stop after
Tripping
1. Turn off the air supply to the air motor.
2. Press the Flush Reset Button (located on
the right side of the Relay Valve item 17)
with a screwdriver or other suitable ob-
ject, (See Illustration 3, below), until the
air motor shifts and the Indicator pin in
item 48 retracts into the Pump Stop. Hold
the reset button until all air has been vent-
ed from the air motor. (On large air mo-
tors this may take several seconds.) Oth-
erwise wait for about 2 minutes until all
air has been vented before attempting a
restart.
3. Turn on air supply and the air motor will
restart.
Illustration 3
4. If the cause of the Pump Stop trip is cavi-
tation or a broken fluid line the Pump Stop
may trip again very quickly.
5. When in the process of setting up a sys-
tem and determining the speed of the
pump/pump tube system use the RUN set-
ting to prevent unnecessary tripping of
the Pump Stop while set-up is in progress
or when trouble shooting the system. Be
sure to reactivate the Pump Stop by re-
setting to the desired run setting before
leaving the pump system unattended.
Illustration 1
Always shut off air supply before
servicing Airmotor. An Airmotor in the
tripped condition is under pressure and
may restart unexpectedly for one or two
cycles.
Illustration 4
Rear View of Pump Stop
Vent Hole
Speed
Setting
Legend
Speed
Setting
Dial