Yaskawa iQpump Controller User Manual - Manual (Page 249)

G.6 Start Level Function
YASKAWA TM.iQp.06 iQpump Controller User Manual 249
P1-04 can be programmed using a negative (-) psi value that will represent an absolute delta draw down of pressure from the auto
setpoint U1-01. Using the same example in Figure G.7 to maintain a 30 psi draw down from either 100 psi or 110 psi, then P1-04 = -30
psi.
Using a negative psi start level will maintain the same delta draw down of pressure 30 psi regardless of the auto setpoint U1-01. By using
this programming method, it is not necessary to reprogram P1-04 when the auto setpoint U1-01 is adjusted.
To program a negative start level, the far left digit must be showing a “-” sign. This is done in programming mode by highlighting the far
left digit and pressing the down arrow on the keypad. When the number zero changes to a negative sign, move the cursor to the far right
and enter in the draw down pressure of 30 psi. Refer to Figure G.7 .
Figure G.6
Figure G.8 -30 psi
Figure G.8 shows a -30 psi Drawn Down Pressure with a setpoint U1-01 = 100 psi.
Negative Sign