Johnson Controls Serie Instrucciones De Instalación página 9

Convertible High Pressure Reset Mechanism on
P70S and P170S Controls
The P70S and P170S controls have a convertible high
side pressure reset. The control may be set to reset
automatically after cutout (when the pressure drops to
cutout minus differential), or to be manually reset after
cutout (by pressing down the reset lever).To change
the reset operation:
1. Disconnect all power sources to the pressure
control and remove the control cover.
2. For Manual Reset Operation: Loosen the lock
nut, and unscrew the stop screw, being careful to
not remove the screw completely from the bracket.
See Figure 10.
For Automatic Reset Operation: Loosen the lock
nut, push the reset lever down, and screw in the
stop screw fully. See Figure 10.
3. Tighten the lock nut to hold the stop screw in place,
and replace the control cover.
4. Restore all power sources and cycle the equipment
to check control operation.
Figure 10: Setting the Convertible High Pressure
Reset Mechanism (P70S or P170S Controls)
Low Pressure Limited Knob Adjustment
Some dual pressure controls are supplied with a
Limited Knob Adjustment kit for the low pressure side
(only) of the control. This restricts the adjustment of the
low-side range and differential screws, and deters
overadjustment or tampering with the control. A stop on
the knob limits adjustment to less than one turn.
P70, P72, and P170 Series Controls for Dual Pressure Applications Installation Instructions
To install the Limited Knob Adjustment kit, see the
following guidelines and steps.
1. To lock the differential adjustment screw and allow
limited adjustment of the range screw, install the
knob on the range screw.
To lock the range screw and allow limited
adjustment of the differential screw, install the knob
on the differential screw.
2. Adjust control pointers to desired high event and
low event setpoints (on All-Range controls), or
differential setting (on MICRO-SET® controls).
3. Place the spacer on the desired adjustment screw.
All-Range controls (with Limited Knob Adjustment
kits) have round and knurled adjustment screws.
The spacer must be placed on the range screw.
MICRO-SET® controls have square adjustment
screws. Always place the spacer on the same
adjustment screw as the knob.
4. Align the large end of the indicator plate over the
adjustment screw with spacer.
5. Align the small end of the indicator plate over the
adjustment screw to be locked.
6. Align the knob over the large end of the indicator
plate.
7. Attach the knob to the adjustment screw, and
tighten the set screw.
Note: The Limited Knob Adjustment kit for the
All-Range controls cannot be used with the
MICRO-SET® controls (and vice-versa).
Figure 11: Limited Knob Adjustment Installation
9