Whats happening here?

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Smart $ said:
+1

And yes to other suppositioned questions as well. :D
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:thumbsup: Let me ask you this can you splice two wires of different sizes?If so are there any limitations?And if you can splice two wires of different sizes can we call this connection as a splice instead of tap?
 
shoaib10 said:
:thumbsup: Let me ask you this can you splice two wires of different sizes?If so are there any limitations?And if you can splice two wires of different sizes can we call this connection as a splice instead of tap?
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In general, a splice is a connection of two or more wires that are protected by the overcurrent protection device (OCPD) at the supply end. They can be different size wires.

A tap is a connection of two or more wires where at least one is protected by the ocpd at the supply end* and at least one is not protected at its rated ampacity, and protection provided at its load end (if it is a feeder/feeder tap situation; branch circuit taps are limited to certain conditions and only protected by the load being not more than the tap ampacity).

*There are instances where feeder taps start at the OCPD terminals and there is no feeder per se.

PS: Look at the rules in 240.21.
 
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Smart $ said:
In general, a splice is a connection of two or more wires that are protected by the overcurrent protection device (OCPD) at the supply end. They can be different size wires.

A tap is a connection of two or more wires where at least one is protected by the ocpd at the supply end and at least one is not protected at its rated ampacity, and protection provided at its load end (if it is a feeder/feeder tap situation; branch circuit taps are limited to certain conditions and only protected by the load being not more than the tap ampacity).
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According to your splice definition if we can do it for two different wire sizes then can we say that the bigger wire and the smaller wire in the picture are spliced?(Provided both the bigger and the smaller wires are protected by the upstream OCPD)
 
shoaib10 said:
According to your splice definition if we can do it for two different wire sizes then can we say that the bigger wire and the smaller wire in the picture are spliced?(Provided both the bigger and the smaller wires are protected by the upstream OCPD)
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That is correct. You would have to determine the ocpd rating at the supply end and the ampacities of the conductors before you could say with absolute certainty whether or not this is a tap scenario.
 
A few things I gathered from looking at the pictures were that, the colors marking the panel are 480v delta, so as one previous poster declared, be careful.

I could read that the polaris lugs are rated for 250MCM. If the largest conductor is indeed 250MCM copper, it would be rated at 290 amps. If the two smaller wires are 2 awg copper, each one could be feeding a panel in two different locations. The CT's appear to be monitoring the power usage on only one set of the wires coming out of the lugs. This could be for several reasons, but often done to divide up an electrical cost, where more than one paying party is involved, or if within an entity, they are determining a budget. With a few more close up pictures of the panel and wiring, a few of these answers could be easily known.

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my_mail_hub said:
A few things I gathered from looking at the pictures were that, the colors marking the panel are 480v delta, so as one previous poster declared, be careful.
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Not that it makes any difference safety wise but, looking at the arrangement of the single pole breakers it is most likely a Wye.

Roger
 
That is a relevant point, but for all we know it is powering 277v lighting, in which case the wild leg voltages wouldn't matter. I find it is on 240v delta panels that the wild legs matter more. Motors and multi volt lighting ballasts dont care too much about the additional voltage from wild legs, which is most commonly what comes out of 480v panels.

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my_mail_hub said:
That is a relevant point, but for all we know it is powering 277v lighting, in which case the wild leg voltages wouldn't matter. I find it is on 240v delta panels that the wild legs matter more. Motors and multi volt lighting ballasts dont care too much about the additional voltage from wild legs, which is most commonly what comes out of 480v panels.

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Are there any wild leg 480V services that have B phase 416V to neutral?
 
shoaib10 said:
Can you explain a little bit more?

I think this picture might help a little bit on whats going on...
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It looks to me like the conductors coming off the breaker are spliced to a parallel set, most likely for voltage drop on that circuit.
 
JFletcher said:
Are there any wild leg 480V services that have B phase 416V to neutral?
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Not that I am aware of. If it is a delta, with a neutral derived between phases will give a reading "like" 285v, instead of 277v between the B or C phase and neutral or ground. If it is a corner grounded delta, you won't get any voltage reading on the grounded phase to neutral or ground, but will still read 480v to neutral or ground on the other legs.

I have seen wire fade in color over time or a gray wire gets used to carry power instead of being used as a neutral and not properly re-identified. This could give you such a reading, if you have a voltage drop for some reason. I have seen voltage drop of about 20v on a 208v Wye system, just from high demand. That is rather peculiar. Perhaps a loose or bad connection. I find loose neutrals on service calls where the voltage reads about 2/3 of what a properly workin circuit would have on 120v circuits. Perhaps the higher voltage overcomes this a bit more, if indeed you are measuring between a misidentified set of wires.

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ggunn said:
It looks to me like the conductors coming off the breaker are spliced to a parallel set, most likely for voltage drop on that circuit.
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Ummm not sure what conductors you are referring to, but if its the phased-taped ones on the bottom left, those are the feeders (or possibly feeder taps).

Don't see any handle-ties and it appears the circuits are run MWBC with so few gray neutral going out on the right. I wonder when it was installed?
 
Smart $ said:
480/240 3Ø 4W delta high leg services and SDS's do exist, though quite uncommon in most the country.
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I have never seen one or even read about one. I had been trying to decide what would be the point of such a creation. Seems like it would be for quite a specific purpose. I have seen 380v 3 phase motors, but 416v to neutral doesn't help you much for a 3 phase motor.

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my_mail_hub said:
I have never seen one or even read about one. I had been trying to decide what would be the point of such a creation. Seems like it would be for quite a specific purpose. ...
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In what limited experience I have with 'em, mostly for 3Ø motor loads, and the center tap just provides for grounding the system rather than running corner grounded or ungrounded with a detector.
 
Basics of electrical ?

Basics of electrical ?

Hello everyone
anyone can describe basics of electrical here please .i want to know because i am new here to work in this industry.
best regards
steve smith
 
steve smith said:
Hello everyone
anyone can describe basics of electrical here please .i want to know because i am new here to work in this industry.
best regards
steve smith
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Basically, it's all about electrons moving around.
 
I do not know where the delta or high leg thoughts came from.

The colors in the panel from the feeder taps (Ilsco) to the main breaker are Brown, Yellow, Orange, a with either a gray or white neutral. Why would delta ever be wired this way? Just because the 480 has an orange wire does not mean "high leg".:?

380 V (400 V) three phase is just the European standard, at 50 Hz. Gives 230 to neutral on Y systems. You see it here when people import European equipment, or when manufacturers here make equipment for the European market.
 
Thanks every one for their answers...:roll::)

I figured it out from everyone's responses and little bit of research..The bigger wire is the feed from the switchboard which is a floor below the panelboard. It comes into the connector and they tap two conductors out of it.One of the wires go the main breaker in the same panelboard and the other feeds a panelboard located a floor below.
 
Frank DuVal said:
I do not know where the delta or high leg thoughts came from.

The colors in the panel from the feeder taps (Ilsco) to the main breaker are Brown, Yellow, Orange, a with either a gray or white neutral. Why would delta ever be wired this way? Just because the 480 has an orange wire does not mean "high leg".:?

380 V (400 V) three phase is just the European standard, at 50 Hz. Gives 230 to neutral on Y systems. You see it here when people import European equipment, or when manufacturers here make equipment for the European market.
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Can you guess what the wire size for the two smaller wires...I was thinking its around maybe #3 or #2...Just need another opinion..
 
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