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5 Clues About Low Voltage Substation Structures

Posted by Brooke Barone on Jan 17, 2014 3:03:00 PM

I’m not too sure how many Nickelodeon-or should I say past Nickelodeon viewers, are reading this article, but there was a popular show in the late 90s-early 2000s, named Blue’s Clues that featured a dog, Blue, and her owner, Steve. The entire show revolved around Blue leaving Steve a series of clues behind with her paw print, and at the end of every show Steve would sit down in his “Thinking Chair” and put the three clues together to come up with the answer. 

Okay so while Blue’s Clues might not indirectly have anything to do with understanding electricity, it does serve as an example that putting clues together can help you better understand what you're looking for.  

Power has to get from point A to B and can be accomplished by either high kV or low kV. Essentially, they do the same thing, just at different voltages. However, when you're driving down the road and pass a substation, there are distinguishing clues that can help you determine if it's a low or high kV substation. 

Clues to spot a Low kV Substation

Terms you'll see used:

  • Switch Stand- function by disconnecting or isolating the current/voltage throughout a circuit.
  • Metering Support- measures voltage or current that passes through the circuit.
  • Box Bay Structure- distribute current to different circuits leaving the substation. 
high low kV
paw printClue #1: The number one clue is the phase spacing. When you start to see combination structures inside a substation, typically, that signals low voltage because phase to ground or phase to phase numbers get much lower and equipment can be placed closer together. One thing to remember is that electricity arcs in the air, so with high voltage, there’s a high potential to arc, therefore equipment has to be spread out further as well as insulated from anything attached to the ground.

describe the imageClue #2: Low voltage substations basically use the same equipment and structures that are found inside high voltage substations, like switches, metering, or some type of recloser or automated clearing mechanism; however, they are just much more condensed. Instead of dedicating an entire structure to only switches in high voltage, on a low voltage structure, there can be different types of switches or a mixture of switches and metering. Basically you’re taking what took you five or six structures used in high voltage, and condensing it to one or two structures with low voltage.

describe the imageClue #3: Typically, you’ll see Box Bay Structures in low kV substations because they allow you to put multiple types of equipment on it, such as switches or metering, and gives more flexibility in how you run your bus work with fewer foundations, as opposed to having to build 10 to 12 for high voltage.


describe the imageClue #4: Normally Riser Structures are not as common at high kV, but you’ll almost always see riser structures with low kV. Riser structures take electricity from above the ground and place it underground. The reason it’s not commonly used in high voltage is because the amount of insulation that it takes to keep high kV voltage underground is more cost-prohibited.

describe the imageClue #5: Generally, you’ll see Station Service Transformers in low kV substations, which are usually attached to other structures like a bus support.  It’s the same transformer that is put on a lower distribution pole in areas like a neighborhood, and provides usable electricity inside the substation. This is for when they do certain things like maintenance work inside the substation where they might need to use a drill or power saw.

Hopefully these 5 clues will help you next time to determine whether you're looking at a low voltage substation or high voltage substation. 

  

Outdoor Substation Design Guide

Tags: low voltage substation structures, box bay structures, riser structures, switch stands, metering supports, distribution structures, low kV substations, termination structures, station service transformers, distribution pole

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