More on коло...

First, thanks to all who responded to yesterday's post. It had been written in a sort of post-workday daze, and I neglected to include information that would be relevant, had I consciously intended for it to be a query. (And thanks to LJ friend ilyavinarsky for the pointer to the ua_mova community.)

For completeness, the inscription I was griping about is on a piece of equipment called a "sparkproof enclosure" (or "intrinsically safe enclosure") which is used to allow electrical connections to equipment situated in explosion-hazardous spaces. The inscription is on a plate on the intrinsically safe side of the apparatus, along with parameter values indicating maximum allowable voltage, current, etc.

On a whim, I decided to Google a Ukrainian search engine and from there, found a document here, which contains the following text in what appears to be a list of tasks:

Розроблення та освоєння серійного виробництва апарату захисту від витоків струму на землю в однофазних колах змінного струму напругою 42/36 В.

Development and introduction [of] mass-produced equipment [for] protection from [???] current to ground in single-phase circuits [with] variable (ac?) current [with] voltage of 42/36 V.

The thing under the original is my attempt at a bastardized "gist" translation, meaning that I looked up each word of the original (here) and then tried to shoehorn the overall result into something that kinda-sorta makes sense.

I could have probably stopped searching after seeing the adjective "однофазних" (virtually identical to the Russian) in front of "колах," since so few nouns in the world are modified by "single-phase," especially in sentences that also contain words like "current" and "voltage" (which is why I looked up those other words). I am now well and truly convinced "коло" means "circuit" in this context.

Cheers...