WESTLOCK CONTROLS CORPORATION
280 N. MIDLAND AVE., STE. 258, SADDLE BROOK, NJ 07663 TEL: 201-794-7650 FAX: 201-794-0913
www.westlockcontrols.com
10/5/2013
TECH-477/D.W.O. 21424
Page 192 of 206
12 Appendix A – Procedure to Adjust the Low Pressure
Setting
The Low Pressure message threshold is pre-set from the factory. For a low
pressure positioner it is set to 15 psi and for a high pressure positioner it is set
at 30 psi. If these settings come out of calibration or if it is necessary to change
these settings, the following instructions can be followed.
1. Before adjusting the Low Pressure threshold setting the positioner must be mounted and set-
up. See section 5 of this manual.
2. To adjust the setting of the Low Pressure threshold message to indicate low input pressure,
there is an adjustment screw located on the top of the pneumatic transducer (see figure below).
3. To set the Low Pressure threshold for an explicit pressure value, loosen the lock nut on the
adjustment screw and
gently
turn the screw clockwise as far as it will go. Do not force the
screw past its limit or diaphragm assembly may be damaged.
4. Regulate the supply pressure to the pressure you would like to set as a low input pressure
flag.
5. Turn the adjustment screw slowly counter-clockwise to the point where the Low Pressure
message appears on the LCD.
6. Set this point by tightening the lock nut. Be careful not to affect the adjustment screw setting.
7. Vary air pressure around low pressure setting and observe LCD to test if setting is correct.
8. Re-regulate the supply air to the normal operating pressure.
