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I am installing an Evaporator Control Limit switch on the…

I am installing an Evaporator...
I am installing an Evaporator Control Limit switch on the outside heat exchanger for the upstairs central heat & air unit in my house. I know that it is just supposed to splice into the low voltage control wire. I just want to make certain that I have the correct wire. My unit has three wires running into it. (See photo). The wire colors are red, black, and blue. Can I safely assume that the slightly smaller gauge blue wire is the correct one (low voltage control)?
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Answered in 13 minutes by:
10/17/2017
Regan Land
Regan Land, HVAC Technician
Category: HVAC
Satisfied Customers: 768
Experience: Over 20 years of experience, NATE Certified, Licensed HVAC Contractor, Certified IAQ Specialist
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Hello and welcome to Just Answer. My name is ***** ***** I'll be happy to assist you today. Those wires in the photo are all high voltage wires that go to the compressor. Can you open the panel that those wires go into and take another picture?

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Customer reply replied 10 months ago
but I am not at home right now. I'll do that when I return home, if it's not too dark. Otherwise, I'll do it tomorrow morning and upload it then.

Okay, thank you

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Perfect, thank you. You see the yellow and brown wires that come through the small triangular panel at the bottom of the electrical section? Those are your low voltage wires from inside. If you remove the triangular cover you will see the connections/wirenuts.
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Customer reply replied 10 months ago
I removed the triangle shaped guard you indicated, and I see the connections. (See photo) Now I just need to verify that the correct place to wire into for the ECL switch is where I indicated in blue (see photo) on the yellow wire. Is that correct?
What is the part # of the ECL you’re using?
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Customer reply replied 10 months ago
Here is what I have, which does say that it should be installed on the "yellow" wire....
"The Evaporater Control Limit Switch (Retrozone p/n) ECL is a widely used freeze stat or freeze protection device designed to prevent Air conditioning coils from freezing. The ECL switch opens its contacts below 38 degrees F, and automatically resets at 50 degrees Fahrenheit. Install the ECL switch by simply snapping it on the the refrigerant "suction" line leading up to the evaporator coil located, outside of the central heat and air fan/furnace housing. Two wires lead from the ECL switch and are spliced into the "yellow" low voltage compressor wire, so compressor operation is stopped when freezing condition are approached."
OKay, yes - you will wire it on the yellow wire so that’s it will break yellow when it gets below 38. Quick question, though - why do you need to install the freeze control?
Regan Land
Regan Land, HVAC Technician
Category: HVAC
Satisfied Customers: 768
Experience: Over 20 years of experience, NATE Certified, Licensed HVAC Contractor, Certified IAQ Specialist
Verified
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Customer reply replied 10 months ago
It's a really long story... the bot***** *****ne is that we often get freeze-ups during the fall & spring for a few reasons, one of which is because I have mismatched coils, with the outside coils being oversized. The mismatch is an even longer story which boils down to money, or lack thereof. So, in order to prevent the freeze-ups and consequently lengthen the life of the comp
Customer reply replied 10 months ago
compressor, I decided to go this route fir less than $10.
Anyway, thanks for the help.
Customer reply replied 10 months ago
I forgot to verify one other thing.... Which coolant line should the sensor/switch be clamped to, the one with the insulation, or the one without? I'm guessing that's a pretty important detail.
Customer reply replied 10 months ago
The coolant line with the insulation on my unit is also MUCH larger than the other line, if that helps.
it will go on the large line with the insulation.
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Customer reply replied 10 months ago
Great! Thanks again!
No problem, thank you!
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Regan Land
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Regan Land, HVAC Technician
Category: HVAC
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