Panels 101: Designing and Building Control Panels

The most critical element that shapes a panel design project must be addressed at the very beginning of a project: where is the completed unit going to be installed? This very basic question dictates the type of protection the enclosure must provide to the equipment. The switchgear inside the enclosure must be protected from the […]

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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 […]

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Tech 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 […]

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Tech 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 […]

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Easily Configure Valve Sizes Fast!

Taking time to size a valve correctly saves you time, money and yourself a headache! Picking the right size leads to performance Our goal is to find the valve with the best control for your specific application. The Cv, or coefficient of flow of the valve, plays a big part in the valve’s performance. A […]

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Relay Fundamentals

Open an HVAC control panel, and you’re likely to find at least one relay mounted inside. Sometimes you find lots of relays! Even though relay technology has been around since the 1800s, there is still a need for relays in control panels. What components make up a relay? How are relays typically shown in wiring […]

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Divide & Conquer Those Hard-to-Read Flow Meter Pulses

Some HVAC applications require reading and totalizing pulses from flow meters.  This sounds simple enough, just take the pulse output from the flow meter, connect it to a Binary Input (BI) on your controller, and set up the program logic to count pulses coming in on the BI.  What could go wrong? Unfortunately things are […]

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“Currently” Playing: Connecting A 4-20 mA Constant-Current Signal To Multiple Loads

One of the most popular and long-lived methods for transmitting analog control signals in the HVAC and industrial control worlds is the “constant-current signal loop.” In this scheme, the value of the current flowing in the circuit is the control variable, rather than any voltages that may appear at different points in the circuit. The […]

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Shedding Some Light On 0-10V Dimmable Lighting Fixtures

  A very popular way to decrease energy usage these days is to use dimmable lighting fixtures and throttle back on the electrical lighting when outdoor light is available through windows or skylights. A light sensor such as the Kele MK7 family can feed light level information into a building automation system (BAS). The BAS […]

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Networking 101: BAS Network Cabling

The various devices comprising a building automation network are either connected by cables or talk wirelessly to each other, or possibly a combination of both.  In Networking 101, we are going to concentrate on network devices connected by cables.  Let’s take a look at the different types of network cables typically encountered in building automation […]

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