Most buildings require some aspect of water flow and, often, BTU measurement. Several different flow sensor techniques can be used depending on need. These include water type, application, accuracy, required measurement, installation challenges, and cost effectiveness. Below is a table to help you determine which technique, product, and installation is most relevant for your project. […]
Read PostCategory: Questions From The Field
Outside Air Temperature Sensor Location
Tech Talk: I need an explosion-proof control panel with a few pilot lights and…
Q: I’ve been buying explosion-proof enclosures and devices from Kele, and I must say that the Hazardous Locations section of your catalog is a gold mine of hard-to-find products! Now I need an explosion-proof control panel with a few pilot lights and externally operable selector switches mounted on the door of the panel. Can Kele help me with […]
Read PostTech Talk: Timing relays are confusing to me. Can you explain the difference between single-shot and interval timers? What happens if the output driving the relay changes state during a timing sequence?
When all of the possible combinations of timing states and initiating device transitions are considered, a stronger word than “confusing” may be in order! Below are some timing diagrams and sequences of operation in simple terms that may be of help. Since it is an electronic circuit that is energized rather than a coil, the […]
Read PostTech Talk: Air Capacity and Consumption – Choosing Electronic to Pneumatic Transducer
When it comes to selecting an electronic to pneumatic (E/P) transducer, the type of input and the pressure range of the output are the most common selection criteria considered. There are a couple of other specifications that are worth reviewing to select the best transducer for the job. These additional specifications are Air Consumption and […]
Read PostTech Talk: Demand Control Ventilation
How many sensors are required in a typical installation? Where should they be located? The number of zones with different occupancy patterns should dictate the number of sensors. In a small office application, for example, it would be ideal to have a sensor in the office space and one in the conference area. Carbon dioxide […]
Read PostTech Talk: 3-Phase Motor with One Lost Phase
Q: What happens to a 3-phase motor when one of the phases is lost? The most extreme case of phase unbalance is the total loss of one of the three phases and is known as phase loss or single phasing. Phase loss can be caused by a broken power line, a lightning strike, an open […]
Read PostQ: The intrinsic safety spec I’m reading calls for an isolated ground. Isolated from what?
Answer: A true isolated ground is not connected to any ground that can ever carry fault current from unrelated parts of the electrical system. It is best to run it directly to grounded building structural steel, an underground metal water pipe, or a separate grounding electrode from the building electrical service as described in Article […]
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