J.R. Merritt Controls MPFC Adjustment Instructions

MPFC Adjustment Instructions
The threshold setting and full output setting are factory adjusted for your specific valve coil. Additional field
adjustments are recommended to tune each machine function to the desired operation.
CW rotation increases the output.
CCW rotation decreases the output.
Some interaction may occur between adjustments of the trim pots and some re-adjustment of the trim pots may be
required to achieve the optimum setting. The trim pots are 22 turn devices and will require several turns before an
appreciable change in response is observed.
Adjustment Priority
1. Full Output Adjust Trim pot (MAX 1): With the handle fully deflected adjust the MAX 1 trim pot CW until the
desired speed is achieved. Caution: Do not over adjust. To insure that the full speed adjustment is not
saturated, back the handle off from full travel 5-10°, a change in performance should be observed. If no change
is noticed MAX 1 is saturated (over adjusted). Turn MAX 1 CCW 5 turns and re-check for a response change
just off the end of the travel again.
2. Threshold (THRES 1): Deflect handle slowly about 5° from off to adjust where the LED turns on then adjust the
THRES 1 trim pot CW to increase the start speed of the function you are controlling. To obtain a slower speed
at this position turn the THRES 1 trim pot CCW until the desired speed is observed. Re-check maximum speed
setting and re-adjust MAX 1 again if necessary to the desired maximum speed. A correctly adjusted controller
will start the function moving when the handle is initially deflected and reach full speed just at the end of travel.
Option Adjustments
3. Dual Full Output Adjust (MAX 2): An independent adjustment of the full output in each direction can be
achieved with this option. MAX 1 adjusts the output at full handle travel in "A" direction. MAX 2 adjusts the
output at full handle travel in "B" direction. Follow the instructions for MAX 1 adjustment above when adjusting
MAX 1 for "A" and MAX 2 for "B" direction.
4. Hi-Lo Range Adjustment (HLRA): Two high-speed settings can be achieved when the handle is fully
deflected. Full proportionality is maintained between the threshold setting and either the low range or the high
range full output setting. The selection of each range is achieved by either connecting or disconnecting the
supply voltage to terminal J5 pin 2. When the supply voltage is applied to J5-2, the circuit selects the high
range setting. When power is removed from J5-2, the circuit defaults to the low range setting.
High Range Adjustment HI (MAX 1): Apply power to J5-2 and fully deflect the handle in the 'A' direction.
Begin adjustment by following Adjustment Priority (1) procedures and adjust MAX 1 trim pot, which is now your
high range trim pot. Whenever source power is connected to J5-2 maximum output will be achieved for this
function.
High Range Adjustment HI (MAX 2): Apply power to J5-2 and fully deflect the handle in the 'B' direction.
Begin adjustment by following Adjustment Priority (1) procedures and adjust MAX 2 trim pot, which is now your
high range trim pot. Whenever source power is connected to J5-2 maximum output will be achieved for this
function.
Low Range Adjustment LO (HI/LO): When the source voltage is disconnected from J5-2 by an external
contact or other means the circuit will default to low range. With J5-2 disconnected deflect the handle fully and
adjust the HI/LO trim pot to the desired low speed output. Again begin this adjustment by following the
procedures outlined in Adjustment Priority (1) for MAX 1 trim pot. With handle fully deflected re-connect the
source power to J5-2 and then disconnect it again. A noticeable change in full output speed should be
observed.
Pub. # 3 7.L 6
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Reference MPFC Electronics Hook up and Wiring Instructions
S trat f ord, CT • • • • 1-800-333-JRMC • • • • www.jrmerritt.com
for trim pot designation code and description.
502