Page 2
B-Low Ambient Pressure Switch Setting (S11)
One of two types of pressure switches are provided. The
Ranco switch has one square and one round adjustment
knob and the Alco switch has two square adjustment
knobs.
Ranco Model
The low ambient pressure switch provided in the kit is
factory set for 285 psig (1965 kPa) cut-in and 140 psig
(965 kPa) cut-out.
If necessary, adjust low ambient pressure switch as
follows:
1-Rotate round knob to set cut-in pressure. Refer to right
set of indicating numbers on face of control. See
figure 3.
2- Rotate square knob to set differential indicator to 145
psig (999 kPa). Refer to left set of indicating numbers.
Alco Model
If necessary, adjust low ambient pressure switch as
follows:
1-Rotate the square knob located on the left to set cut-in
pressure. Refer to left set of indicating numbers on
face of control. See figure 2.
2- Rotate the square knob located on the right to set
differential indicator to 145 psig (999 kPa). Refer to
right set of indicating numbers.
3- Use only terminals 1 and 4 when connecting wiring.
NOTE - Disregard Cut out minus Diff. is Cut In"
statement on face of control. This does not apply in this
application.
C-Low Ambient Relay (K58)
1- Install low ambient relay in control box.
LOW AMBIENT PRESSURE SWITCH S11 DETAIL
SQUARE DIFFERENTIAL
ADJUSTMENT KNOB
FIGURE 2
ROUND CUT-IN
ADJUSTMENT
KNOB
PRESSURE SWITCH IS FACTORY-SET AT 285 PSIG CUT-IN
AND 145 PSIG DIFFERENTIAL (140 PSIG CUT-OUT)
CUT-IN PRESSURE
READOUT ON
RIGHT
DIFFERENTIAL
PRESSURE READĆ
OUT ON LEFT
SQUARE DIFFERENTIAL
ADJUSTMENT KNOB
ROUND CUT-IN
ADJUSTMENT
KNOB
CUT-IN PRESSURE
READOUT ON LEFT
DIFFERENTIAL
PRESSURE READĆ
OUT ON RIGHT
RANCO MODEL
ALCO MODEL
