Low Voltage EGC requirements

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Stonewall

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What are the EGC requirements for low voltage circuits? At what AC voltage is an EGC no longer required? At what DC voltage is an EGC no longer required?
 
This depends on what the 24 volts is used for. There is no lower limit on the rules in Article 250, but there are rules in some Chapter 7 Articles that say you don't need the EGC.
 
Stonewall said:
I searched chapter 7 and couldn't find any mention of EGC or equipment grounding conductor.
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If there is no mention, then the rules in Article 250 apply since the rules in Chapters 5-7 supplement or modify the rules in Chapters 1-4.
 
Although I couln't find any mention of an EGC in chapter 7, someone pointed out to me that 725.3 completely exempts class 1/2/3 circuits from having to comply with article 250; therefore circuits at 30V and lower do not require an EGC.

I think the article in the previous post's link comes to the same conclusion for almost the same reason.
 
I don't see anything in 725.3 that says Article 250 does not apply.
725.3 Other Articles.
Circuits and equipment shall comply with the articles or sections listed in 725.3(A) through (G). Only those sections of Article 300 referenced in this article shall apply to Class 1, Class 2, and Class 3 circuits.
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(edit)Nevermind...I see it now, but Class 1 systems can be 120 volts or more...why don't they require an EGC?
 
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Maybe I don't see it. The wording is not completely clear. It does not say that Article 725 systems are only required to comply with the listed sections, it just says you have to comply with the listed sections. However, it specifically says you are only required to comply with the sections of Article 300 that are referenced in Article 725. If both parts of 725.3 really mean the same, then why the different wording.
 
Your right. We aren't limited to 30V. See 725.41b. As long as the circuit is used for remote-control or signaling and does not exceed 600V, then it can be considered a Class 1 circuit. Since 725.3 doesn't specify that arcticle 250 applies, then Class 1 circuits do not have to comply with arcticle 250.

So the way I read this; the following circuits do not require an EGC:
120Vac start/stop motor controls
120Vac pressure switch signal
125Vdc switchgear close and trip controls
125Vdc door alarm signal
24Vdc level alarm signal
24Vdc analog (4-20ma) control
24Vdc analog (4-20ma) signal

Anyone disagree?
 
I could be wrong, but this is the way I see it. Other chapter 7 articles specify what other articles apply. In 700.2, it specifies that all other arcticles apply. Since 725.3 omits article 250, then 250 doesn't apply.
 
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