Sterlco SPV Remote Proportioning Devices - Manual (Page 20)

Remote Proportioning Valve Chapter 4: Operation 20 of 28
4-3 Hopper Loader Conversion Operation
The SPV-C converts 9953 and 9963 hopper loaders into proportioning hopper loaders using
the controls included with existing STERLING models.
If you are familiar with the operation of 9955 and 9965 proportioning hopper loaders, the
SPV-C is operated in the same manner. Adjust the potentiometers in the control enclosure as
you would with a 9955 or 9965. Refer to the Operation and Installation Manual supplied with
your existing proportioning hopper loader for complete information.
If you are not familiar with the proportioning feature available in 9953 and 9963 Hopper
Loaders, read the following for the adjustment procedure and refer to Figure 8.
Figure 8: Control Box Adjustment Diagram
DANGER!
The adjustment procedure described below involves working inside the
control box. Dangerous electrical current may be present during
potentiometer adjustment. Only qualified, safety-conscious personnel may
make these adjustments.
The adjusting potentiometers (or pots) are located in the hopper loader control box. Pots 1, 2,
and 3 control the pulse, blowback, and vacuum times. These pots have already been adjusted
to your application, and need no further adjustment.
Pots 4 and 5 are used to control the Remote Proportioning Valve. These thirty-turn pots
control a twenty-second maximum length proportioning cycle that runs independently of the
conveying (Vacuum, Pot 3) time.
Turn pots 3 and 4 clockwise to increase the respective material ON times. Turn them counter-
clockwise to reduce the material ON times.
Example 1
If both Pots 3 and 4 were turned to their maximum setting, each material would be conveyed
for 10 seconds; alternating until the convey (Vacuum pot 3) cycle times out. The
proportioning cycle time is at its maximum length (20 seconds). If the conveying cycle is set
at sixty (60) seconds (three 20 second proportioning cycles), Materials A and B will alternate
ON three times a cycle for 10 seconds each, creating a 1:1 ratio.
Example 2
If Pot 3 is set at the maximum setting and Pot 4 is turned to a middle setting, Material A
would be conveyed for 10 seconds and Material B would convey for 5 seconds. The resulting
15 second proportioning cycle would repeat four times during a 60 second convey cycle. This
setting would creates a 2:1 proportion ratio under ideal conditions.
Adjust the pots to suit your unique processing requirements, noting the concepts described in
Section 2-3 “How it Works” on page 7. Refer to Section 4-4 on page 21 for instructions on
delivering known proportions.