Showing posts from December, 2020

How LVDT Pressure Sensors Work?

Pressure sensors - commonly referred to as pressure transducers, pressure transmitters, pressure indicators or pressure switches - are used to measure the pressure of gases and liquids (fluids). Pressure is an expression of the force and is normally stated in terms of force per unit area. A pressure sensor will generate an electrical signal relating to the pressure imposed. This signal is either analogue or digital in more modern designs, although optical, visual and auditory signals are also common. Industrial pressure transducers normally have a diaphragm type design that uses strain gauges, which are either bonded to, or diffused into it, with the strain gauges acting as resistive elements. Under the pressure-induced strain, the resistive values change. In capacitive technology, the pressure diaphragm is a single plate of a capacitor that

Smoke-Spill Induction Motors

Smoke spill fans and motors are designed to be capable of operating during a fire long enough to expel smoke until the occupants of the building are evacuated. They are used in high-rise buildings, tunnels and similar applications. While many in the industry are aware of the term and its definition under Australian Standards 1668, there is some confusion among motor and fan suppliers on what features their particular motor should incorporate to ensure its stability for this application. Standardized testing procedures are to be put in place soon that should result in a clearer understanding of smoke spill requirements and thus help dispel this confusion. Keen to take the initiative in this matter and establish our own smoke spill question, WE undertook a series of tests on tis motors. The WE series of three tests was conducted in rigorously controlled conditions using class F and H insulated 4 kW 4 pole motors. The motor/fan assembly (which had previously been run in nor

Ex 'E': Short on Name - Long on Safety

What does increased safety mean? It centres on AS 2380.6-1988 covering motors for hazardous situations. Western Electric's Ex ‘e’ range of motors are manufactured to meet these strict requirements which makes them suitable for operation in locations where sparks and hot surfaces could ignite combustible gases. EX Explosion Proof Motors AS 2380.6-1988 defines 'Increased Safety' as: 'The type of protection applied to electrical equipment that does not produce arcs and sparks in normal service in which additional methods are applied so as to give increased security against the possibility of excessive temperatures and of the occurrence of arcs and sparks.' The increased Safety requirement ensures that motors are suitable for safe operation in hazardous locations where sparks and hot surfaces could ignite combustible gases to cause a disastrous explosion. Additional measures in the design and manufacture of Ex ‘e’ motors make sure that they do