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 PostCategory: Technical Reference
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 […]
Read PostEasily 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 […]
Read PostRelay 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 […]
Read PostDivide & 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 […]
Read Post“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 […]
Read PostShedding 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 […]
Read PostNetworking 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 […]
Read PostConnecting A Voltage-Output Signal Source To Multiple Loads
The Tech Support crew here at Kele frequently gets quizzed by customers who have a voltage-output signal source which must drive multiple voltage-input loads. Requests for “voltage signal replicators” come in frequently. Sometimes extra hardware is needed, but sometimes it isn’t! So we thought it might be a good idea to write an article addressing […]
Read Post47 Ways to Wire Your Power Meter Wrong
Some of you might remember that back in 1975 Paul Simon had a hit song entitled “50 Ways to Leave Your Lover.” Well, coming in a close second are the number of ways (47) that you can wire a 3-phase power meter incorrectly! In this article we’ll briefly discuss why there are so many ways […]
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