I'm trying to understand my own condo's electrical service.
The pole transformer has 2 primary bushings. 2 distribution lines are running to it. One of the primary bushings is connected to the highest line on the pole via a fuse cutout. The other is connected to a lower line right above the pole transformer, what I would originally postulate is the neutral line, without a fuse cutout in between. Conflicting information tells me that single phase pole transformers with 2 primary bushing are on a delta distribution circuit, and those 2 primaries are each connected to hot leg lines, with no neutral returning to the substation.
How can I tell if a line is a 'hot' or a 'neutral' coming to a single phase, double primary bushing, pole transformer?
How can I determine if I'm on a delta distribution circuit? (I.e. no neutral returning to substation/use of delta hot legs for return paths)
Also, the *secondary* center tap also appears to be tapped directly to that same lower line, which also makes me think it is a neutral.
That being said, is it untrue that a single phase transformer with 2 primary bushings is always connected to 2 'hot' primary lines for the line-to-line derivative for 240V?
Additionally, there are 2 sets of 3 wires coming down from the secondary to feed the units. 2 hots and a neutral in each I would assume, because we have 120/240V service. But if the primaries are tapped to one leg of hot and one leg of neutral, how are we deriving the second hot wire in the secondary system? Considering the scenario that one primary bushing as well as the secondary center tap are connected to that same neutral line, how are we getting the phase-phase potential difference needed for a 240V supply?
And if the lower line on the pole is actually another hot leg and not a neutral, why would the secondary center tap be connected to it? And why would there not be a fuse in between that connection?
I've gone around and around trying to determine what's happening here. Insight will be much appreciated.
(Side note, the primary bushings predate 1979 by the looks of them)
The pole transformer has 2 primary bushings. 2 distribution lines are running to it. One of the primary bushings is connected to the highest line on the pole via a fuse cutout. The other is connected to a lower line right above the pole transformer, what I would originally postulate is the neutral line, without a fuse cutout in between. Conflicting information tells me that single phase pole transformers with 2 primary bushing are on a delta distribution circuit, and those 2 primaries are each connected to hot leg lines, with no neutral returning to the substation.
How can I tell if a line is a 'hot' or a 'neutral' coming to a single phase, double primary bushing, pole transformer?
How can I determine if I'm on a delta distribution circuit? (I.e. no neutral returning to substation/use of delta hot legs for return paths)
Also, the *secondary* center tap also appears to be tapped directly to that same lower line, which also makes me think it is a neutral.
That being said, is it untrue that a single phase transformer with 2 primary bushings is always connected to 2 'hot' primary lines for the line-to-line derivative for 240V?
Additionally, there are 2 sets of 3 wires coming down from the secondary to feed the units. 2 hots and a neutral in each I would assume, because we have 120/240V service. But if the primaries are tapped to one leg of hot and one leg of neutral, how are we deriving the second hot wire in the secondary system? Considering the scenario that one primary bushing as well as the secondary center tap are connected to that same neutral line, how are we getting the phase-phase potential difference needed for a 240V supply?
And if the lower line on the pole is actually another hot leg and not a neutral, why would the secondary center tap be connected to it? And why would there not be a fuse in between that connection?
I've gone around and around trying to determine what's happening here. Insight will be much appreciated.
(Side note, the primary bushings predate 1979 by the looks of them)