Omega Engineering PSW 18 P manual Switch Selection and Mounting Instructions, AT Imax

P N E U M A T I C , D I A P H R A G M - S T Y L E P R E S S U R E S W I T C H

SWITCH 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 Points

ADJUSTMENT OF SWITCHING POINT

Locking Screw

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 rotation 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.

MAKING AND BREAKING CAPACITY

	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 104	approx 107
(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 105	approx 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 current to 50% of Imax approximately doubles contact life.