Install Instructions

Table 1: Single Pressure Controls Switch Action, Low Events, High Events, Model Types, and Electrical
Rating Table References
Switch and Action Low Event High Event Model Types - Electrical
Rating Table Reference
Single-Pole Single-Throw
(SPST) Open-Low
Cutout
(Opens Line to M1)
Cut In
(Closes Line to M1)
P70A, P70B, P170A
See Table 3.
SPST Open-High
Cut In
(Closes Line to M1)
Cutout
(Opens Line to M1)
P70C, P70D, P170C, P170D
See Table 3.
Single-Pole Double-Throw
(SPDT)
Opens 1 to 2 and
Closes 1 to 3
Closes 1 to 2 and
Opens 1 to 3
P70E
See Table 4.
4-Wire, 2-Circuits,
1 N.O., 1 N.C.
Open-Low
Cutout
(Opens M2 to Line and
Closes M1 to Line)
Cut In
(Closes M2 to Line and
Opens M1 to Line)
P70G, P70H
See Table 5.
4-Wire, 2-Circuits,
1 N.O., 1 N.C.
Open-High
Cut In
(Closes M2 to Line and
Opens M1 to Line)
Cutout
(Opens M2 to Line and
Closes M1 to Line)
P70J, P70K, P170K
See Table 5.
Double-Pole Single-Throw
(DPST)
Open-Low
Cutout
(Opens M1 to Line and
M2 to Line)
Cut In
(Closes M1 to Line and
M2 to Line)
P72A, P72B
See Table 6.
DPST
Open-High
Cut In
(Closes M1 to Line and
M2 to Line)
Cutout
(Opens M1 to Line and
M2 to Line)
P72C, P72D
See Table 6.
Adjustments
Adjustment of the P70, P72, and P170 low pressure
controls varies, depending on the model. The following
guidelines and diagrams illustrate the procedures for
adjusting these controls. Refer to the product label
inside the control cover for model number and switch
action, and check the front of the control cover to
determine if the control is an All-Range or MICRO-SET
model. See Table 1 for switch action, low event, and
high event of the various control models. See Figure 8
for an illustration and instructions on control
adjustments.
Adjusting All-Range Controls
All-Range pressure controls have scaleplates that
display the Cut In and Cutout setpoints. (See the
visible scale on the control.) Turn the range screw to
adjust the Cut In and Cutout setpoints up or down
simultaneously while maintaining a constant pressure
differential. Turn the differential screw to adjust (only)
the low event on the left side of the scale (which
changes the differential pressure value).
Adjusting MICRO-SET Controls
MICRO-SET low-side pressure controls have
scaleplates that display the Cut In setpoint and
Differential setting. (See visible scale on control.) Turn
the range screw to adjust the Cut In setpoint on the
right side of the scale. Turn the differential screw to
adjust the differential setting on the left side (which
changes the Cutout pressure value).
IMPORTANT: Do not adjust pointers beyond
the highest or lowest indicator marks on the control’s
pressure scale. Adjusting pointers beyond indicator
marks may damage screw threads, may cause
inaccurate control operation, and will void the
warranty.
IMPORTANT: Use the pressure control
settings recommended by the manufacturer of the
controlled equipment. Do not exceed the pressure
ratings of the controlled equipment or any of its
components when checking pressure control
operation or operating the controlled equipment.
IMPORTANT: After mounting and wiring
control, attach a reliable set of gauges to the
controlled equipment, and operate the equipment (at
least) three cycles at the pressures necessary to
verify control setpoints and proper equipment
operation.
4 P70, P72, and P170 Series Controls for Low Pressure Applications Installation Instructions