What is the difference between a Namur valve position switch and an SPDT switch?
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Today I saw several specification sheets; I’m not quite sure whether limit switches and valve position switches are the same thing, and what’s the difference between Namur and SPDT.
Namur is a switch signal for microcurrents; you can look it up on Baidu. As for SPDT, I don’t know either
SPDT stands for single pole double throw, while DPDT stands for double pole double throw
NAMUR is a low-current signal similar to a safety barrier; SPDT refers to dry contacts. The NAMUR switch itself has current-limiting capabilities, but ordinary DCS DI cards cannot receive this signal directly – an isolation barrier can be used for conversion
The Namur limit switch signal is a current-limiting signal with a voltage of 8V and a current of 2.1MA or less; proximity magnetic switches, which are intrinsically safe, are generally used for this purpose. SPDT is a mechanical contact-type signal switch contact.
The Namur limit switch signal is a current-limiting signal with a voltage of 8V and a current of 2.1MA or less; proximity magnetic switches, which are intrinsically safe, are generally used for this purpose. SPDT is a mechanical contact-type signal switch contact.
This post was last edited by Fire Dance_MY8cj on 2020-9-4 at 12:27. NAMUR (valve open and closed position) means that the positions of the valve when it is open or closed comply with the German NAMUR standards. SPDT*2 means that the switch is a set of [2] mechanical single-pole double-throw switches
The numur signal is a intrinsically safe signal that must pass through a safety barrier to reduce its energy through voltage and current limitation； SPDT is a mechanical dry contact switch
NAMUR is a proximity switch, while SPDT is a microswitch.