MAKING AND BREAKING CAPACITYSWITCH SELECTION AND MOUNTING INSTRUCTIONS
• Select a switch such that the desired switching point falls roughly
in the middle of the adjustment range.
• Do not exceed switch electrical ratings. Use an appropriately sized
relay when switching larger electrical loads.
• For media with pressure spikes and/or pulsating pressures,
install a pressure snubber.
• For outdoor applications, sufficient protection must be provided.
ADJUSTMENT OF SWITCHING POINT
Either the upper or the lower switching point may be adjusted.
The opposite one is then fixed by the hysteresis characteristics of the switch.
Use a pressure gauge for exact adjustment. Proceed as follows:
1. Loosen locking screw.
2. Adjust the switching point using a 5-mm hexagon wrench. Clockwise r otation
increases switching pressure and counter-clockwise rotation decreases switching
pressure. Low-end of adjustment range is reached when top of adjustment barrel is
approximately level with top of switch housing. High-end of adjustment range is
reached when adjustment barrel is fully CW.
3. Re-tighten locking screw.
TYPE TYPE VMIN MAXIMUM PERMANENT CONTACT LIFE
LOAD OF OF [V] CURRENT IMAX [A] AT V ELECTRICAL MECHANICAL
LEVEL* CURRENT LOAD 24 V 125 V 250 V AT IMAX AT I ≈0
Standard AC Resistive 12 5 5 5 5 x 104approx 10 7
(relays, switching switching
solenoids) AC Inductive 12 3 3 3 cycles cycles
PF ≈.7
DC Resistive 12 5 .4 _
DC Inductive 12 3 .05 _
L/R ≈10 ms
Low AC Resistive 5 .34 .08 .04 2 x 10 5approx 107
(electronic switching switching
circuits) DC Inductive 5 .1 _ _ cycles cycles
L/R ≈10 ms
*Load Level Explanation
PSW18P Series pressure switches have microswitch contacts
with gold plating over silver base metal. The gold plating
remains intact when “low level” voltage / current levels are
observed. This feature assures highly reliable switching in
low-level electronic circuits.
Standard applications do not require the gold plating – which
will decay naturally when switching larger electrical loads.
Notes:
1.Reference conditions:
30 cycles per min and 86°F (30°C) ambient.
2.Reducing load cur rent to 50% of Imaxapproximately
doubles contact life.
Adjustment Of Switching Points
Locking Screw

PNEUMATIC, DIAPHRAGM-STYLE PRESSURE SWITCH