Astra Automatyka > Produkty > Sensors and transducers > Pressure > Mechanical pressure switches for liquids and gas Ex-VCM and Ex-VNM HONEYWELL
Mechanical pressure switches for liquids and gas Ex-VCM and Ex-VNM HONEYWELL

FEMA / Honeywell negative pressure switches Ex-VCM and Ex-VNM detect the pressure difference relative to atmospheric pressure. All data relating to the switching pressure ranges and thus also the scal...

FEMA / Honeywell negative pressure switches Ex-VCM and Ex-VNM detect the pressure difference relative to atmospheric pressure. All data relating to the switching pressure ranges and thus also the scale divisions on the switching devices are to be understood as the difference in pressure between the releant atmospheric pressure and the set switching pressure.


Product comparison
Type Setting range Switching differential
(mean values)
Max. permissible
pressure
Ex-VCM095 -0,9…+0,5 bar 50 mbar 3 bar
Ex-VCM101 -1…+0,1 bar 50 mbar 3 bar
Ex-VCM301 -250…+100 mbar 25 mbar 1.5 bar
Ex-VCM4156 -15…+6 mbar 2 mbar 1 bar
Ex-VNM111 -1…+0,1 mbar 50 mbar 6 bar
Ex-VNM301 -250…+100 mbar 45 mbar 3 bar

* At very high vacuums, close to the theoretical maximum of –1 bar, the switch may not be usable in view of the special conditions of vacuum engineering. However, the pressure switch itself will not be damaged at maximum vacuum.

Mechanical pressure switches for liquids and gas Ex-VCM and Ex-VNM HONEYWELL

The “zero” reference point on the scale of the unit corresponds to the relevant atmospheric pressure.
The maximum medium temperature at the pressure sensor must not exceed the permitted ambient temperature at the switching device. Higher medium temperatures are possible provided the above limit values for the switching device are ensured by suitable measures (e.g. siphon).
The Ex-VCM and Ex-VNM Honeywell / FEMA series are calibrated for falling pressure. This means that the adjustable switching pressure on the scale corresponds to the switching point at falling pressure. The reset point is higher by the amount of the switching differential.

Parameter Value
Kind of pressure vacuum, relative
Pressure connection internal thread G¼, external thread G½
Electrical connection terminal connection M16x1,5
Protection class IP65
Housing material rugged housing of seawater resistant aluminium die casting GD Al Si 12
Media temperature -15 ... 60°C
Media temperature limit higher temperatures are possible, provided that the limit is safeguarded by suitable measures (e.g. water tube trap, see Accessories for Pressure Switches / Transmitters)
Ambient temperature -15 ... 60°C
Ambient temperature limit at temperatures below 0°C, ensure that no water condensation can arise in the sensor and in the switching device
Switch function/capacity SPDT Microswitch 250 VAC; capacity 2 A inductive, 3 A resistive
Certificates • SIL2 according IEC 61508-2
• IBExU12ATEX1040 according to ATEX 94/9/EC
• IECEx IBE 14.0077
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