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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Controls and Cables in Environmental Air Handling Spaces, Ducts, and Chases

First, let’s discuss controls and their enclosures in air handling spaces, ducts, and plenums. Many times, we have to install items in these spaces and it’s important to consider that anything we put in there should either be non-combustible (metal) or else be listed under UL 2043 for use in air handling spaces. The NEC […]

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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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Connecting 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 […]

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47 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 of them) that you can wire a 3-phase power meter incorrectly! In this article we’ll briefly discuss why there are so […]

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Hot and Steamy Pig Tails! How to Measure the Pressure of Steam Without Breaking Your Pressure Transmitter

So, in checking the specs, the PTX1-06, can read pressure up to 200 degrees Fahrenheit, like most pressure transmitters in the marketplace. But, steam is steam at 212 degrees Fahrenheit. How’s that going to work? This little piggy says to put a copper extender on a pig tail, and shoot the steam to the side […]

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What’s the Real Difference Between CO and CO2?

In the past few years, there has been a lot of media attention brought to carbon monoxide (CO), as well as carbon dioxide (CO2) and their affect on occupied spaces and indoor air quality. Both are colorless and odorless gases that can have a negative impact on building occupants. However, be sure you know what […]

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