Pressure Switch with Bellow Type (502/7DC)

The Sensor of the Switches is bellows, can be apply to gas, air, water such medium neutral gas, and lube, light fuel such liquid medium. The Set Point is adjustable, and its adjustable range is from -0.1 to 4 Mpa. The shell material is Casting Aluminum, water-proof structure can meet the requirements of vessel use.

* The Switch is microminiature structure.
* Non-adjustable switch has Mini Dead Band type.
Technical Performance:
Anti-Vibration: 40m/s2
Max. Allowable Pressure 150%
Working Life 105 time
Medium Temperature -25º C~80º C
Ambient Temperature: -25º C~55º C
Working viscocity <1x10-3m2/s
Electrical rating: AC 380V, 3A(Resistance)
AC 220V 6A(resistance)

The Adjustment for Dead Band Non-Adjustable Switches
The Adjustment steps of the Decreasing Set Point
Example 1, Choose Table NO. 1, series No. 7 switch, a contact signal is required to be generated when pressure fall to 0.5Mpa(the Decreasing Set Point), the steps listed below:

1) Loose the locknut, screw the switch into the threaded connection of Checkout Test Set. Use the spanner to clip the flat port of the sensor to avoid countermovement of the housing and the sensor.

2) Open the front cover of the switch, let the cable pass through electrical connection and link to the terminal, link another end to the multimeter.

3) Add the pressure to 0.5Mpa, this value can be read from the standard pressure gauge.
4) Clockwise rotate the Set Point Adjusting bolt, to make the Set Point change from big to small, until it switchs at 0.5Mpa.
5) Tighten the locknut, adjust the pressure of the testing desk, to make the pressure change up and down around 0.5Mpa, to test if it switches at 0.5Mpa when pressure is rising. Its correspondent Decreasing Set Point just to be 0.5Mpa minus Dead Band 0.035Mpa(approximately), to be 0.465Mpa(approximately).

The adjustment steps of the Increasing Set Point
Example 2. Choose Tabel no. 2, series no. 7 switch, a contact signal is required to be generated when pressure rise to 0.5Mpa(the Increasing Set Point). The steps listed below:

1) same steps like example 1(from step 1 to step 4), set the Decreasing Set Point to be 0.5Mpa
2) Clockwise rotate the Set Point Adjusting bolt, to make the Set Point change from big to small, until it switchs at 0.5Mpa.
3) Tighten the locknut, adjust the pressure of the testing desk, to make the pressure change up and down around 0.5Mpa, to test if it switches at 0.5Mpa when pressure is rising. This is the Increasing Set Point to be set, its correspondent Decreasing Set Point just to be 0.5Mpa minus Dead Band 0.035Mpa(approximately), to be 0.465Mpa(approximately).

While removing the cover, please do not touch any component inside the switches.
The Set Point must be within the aAdjustable Range, Dead Band is expressed as Typical at mid-range. Normally it is the 20% to80% of the Ajustable Range.

The Dead Band Adjustable Range in the table are the minimum adjustable range which can be guaranteed, the practical range can be wider.

The testing pressure should not exceed the Max. Allowable Pressure.
There should be no corrosive gas in the surrounding atmosphere.
During the process of installation or disassembly, a spanner MUST be used to clip and tighten the sensor, absolutely avoid the countermovent between the sensor and housing of the switches(please refer to the drawings)