Control circuit

[roger]

I am not wiring this thing. I am just a reviewer and not by choice they gave this to review.

Maybe the reality is you should tell them this is outside your expertise and they need to find someone else to review it.

With that said, why are you reviewing an engineers drawing in the first place?

Roger

 

[hhsting]

Maybe the reality is you should tell them this is outside your expertise and they need to find someone else to review it.

With that said, why are you reviewing an engineers drawing in the first place?

Roger

True I told them that in writing and verbally and I was told I am the most knowledgable person here. I am just not gonna do it for this project.

I am plans reviewer as contractor to an AHJ so thats what I mostly do review plans. There are times I go to field as inspector but very few of them not this project. Sometimes I also do design as engineer and I am on other side of table. Some of the strangest, weird questions I ask are really on plans with professional engineer stamp and seal. Plans get approved and go to inspection but not necessary that they are built that way inspector or master electrician may alter the plans. I apologize in advance if I am causing any trouble here but this forum has the most knowlegable group of people and I am only asking their opinion.

 

[roger]

Thank you for the clarrification.

Roger

 

[kwired]

I am not wiring this thing. I am just a reviewer and not by choice they gave this to review. Now I do know why EGC are provided. However controls are different then power circuits. The control circuits that I have does not have overcurrent protrection and so question was how to size wire gauage.

I placed this question multiple thread because no one gave answer nor no one helped answer question. I was thinking if not this forum then another forum might have people who know something. Looks like the thread are seen by same people no matter where you placed it.

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Control circuits can have different overcurent protection limitations than what the general requirements limit you to.

Class 2 control circuits as mentioned are power limited and for the most part there isn't enough current available that there is a minimum requirement on conductor size when it comes to protecting conductor insulation from results of overcurrent. Minimum sizes may be more important to the equipment operation itself - say for voltage drop reasons.

Such power supplies for these kinds of circuits often are impedance limited, they can't deliver enough power to create too much heat in the conductor to be an issue.

Sometimes such systems are not grounded either, an EGC doesn't do all that much in those cases. All it can do is bond equipment at one end of the run to equipment at the other end, which often won't really serve much useful purpose anyway. If it were something within a hazardous location it may be necessary just to help limit risk of producing arcing/sparking on exterior of raceways/enclosures, but for non classified area there isn't much benefit.