The high leg has been known to be on the C phase. I don't believe their is a code issue on it but rather what the power company may require or what is normally used in that area.
High Leg System
I have a question in regards to the Wild Leg being installed on the wrong phase. This panel has the wild leg on Phase C. Was it done this way in the 70's?
I am having to add another panel off of the main, and I have no use of the wild leg.
Usually I always add a 3 Phase sub panel off of a 3 Phase main, but is there any reason to add a 3 phase sub panel here? As for the loads on the panel; Phase A has 44 amps, Phase B has 50 amps, and Phase C has 0 amps (the ac's were not on). I understand balancing the load, but obviously I will not be using the wild leg for any loads. How does this affect balancing the loads?
I am young and have not dealt with many wild leg systems. Please provide me with any insight you can.
Thanks
I am having to add another panel off of the main, and I have no use of the wild leg.
Usually I always add a 3 Phase sub panel off of a 3 Phase main, but is there any reason to add a 3 phase sub panel here? As for the loads on the panel; Phase A has 44 amps, Phase B has 50 amps, and Phase C has 0 amps (the ac's were not on). I understand balancing the load, but obviously I will not be using the wild leg for any loads. How does this affect balancing the loads?
I am young and have not dealt with many wild leg systems. Please provide me with any insight you can.
Thanks
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I don't understand. The code has required the high leg to be on B phase since before I started in the trade. The power company often landed the high leg on the C phase in the meter, but the electrician was required to land it on B phase in the service equipment.The high leg has been known to be on the C phase. I don't believe their is a code issue on it but rather what the power company may require or what is normally used in that area.
As far as I know, even where the power company landed the high leg in the C phase position, it was actually B phase in terms of the phase rotation. Landing it in the C phase position had something to do with the metering equipment operation.
You are correct-- I looked for it in 110 but it is in art. 408. B phase is high leg but I have heard others say their area required it on C phase.I don't understand. The code has required the high leg to be on B phase since before I started in the trade. The power company often landed the high leg on the C phase in the meter, but the electrician was required to land it on B phase in the service equipment.
As far as I know, even where the power company landed the high leg in the C phase position, it was actually B phase in terms of the phase rotation. Landing it in the C phase position had something to do with the metering equipment operation.
Our POCO requires it to be C phase and identified with purple...:blink:
After the meter or C/T can the electrician puts it on B and marks it with orange.
Pete
After the meter or C/T can the electrician puts it on B and marks it with orange.
Pete
Had the old brain fart-- I always thought the B phase was required but when I read 110.15 it didn't mention B phase. I thought I was incorrect about the B phase. Found it later in 408.3(E)
There is no code reason why the color has to be changed from purple to orange.Our POCO requires it to be C phase and identified with purple...:blink:
After the meter or C/T can the electrician puts it on B and marks it with orange.
Pete
True. Thats just how it's identified around here.There is no code reason why the color has to be changed from purple to orange.
Pete
A lot of older installs just carry the high leg from C position at the the meter and carry right through to the panel.
Often with HLD services it's preferred to have three phase main panels with single phase subs. Use the three phase panel for the three phase loads and any 2 wire 240v single phase loads to balance as best as possible. All the 3 wire 240 volt loads and the 120 stuff go in the single phase panel. Gives you the best usage of spaces and adds a bit (a tiny bit) of idiot resistance.
Often with HLD services it's preferred to have three phase main panels with single phase subs. Use the three phase panel for the three phase loads and any 2 wire 240v single phase loads to balance as best as possible. All the 3 wire 240 volt loads and the 120 stuff go in the single phase panel. Gives you the best usage of spaces and adds a bit (a tiny bit) of idiot resistance.
Actually it does say orange.There is no code reason why the color has to be changed from purple to orange.
It does say orange but it also says "or by other effective means".Actually it does say orange.
An AHJ may interpret that purple tape is an effective means.
Pete
Here in Chicago B phase red tape. Stupid yes
True. I just keep it orange. That's the norm.It does say orange but it also says "or by other effective means".
An AHJ may interpret that purple tape is an effective means.
Pete
Most guys around here (including me) have always interpreted this another way, that it was to be identified with the color orange. The orange identification can be either by its outer covering (THHN with orange insulation) or another effective means like orange phase tape or orange paint. The constant being that it was orange.It does say orange but it also says "or by other effective means".
An AHJ may interpret that purple tape is an effective means.
Pete
Do you agree that by"other means" that you can mark it with a tag or something similar?Most guys around here (including me) have always interpreted this another way,
That is how I see it.It does say orange but it also says "or by other effective means".
An AHJ may interpret that purple tape is an effective means.
I will asume that the original service is 240 volt three phase? If you are adding any 240 volt, single phase loads - THAT DO NOT HAVE ANY 120 VOLT EQUIPMENT CONNECTED WITHOUT AN UPSTREAM TRANSFORMER, you can connect one leg of a 240 volt, single phase load to the "high leg." Any equipment that is 240 volt only (with no neutral required) will function just fine using the "high leg", as the high leg to either of the other phases will read 240 volts.
BE CERTAIN TO NOT CONNECT ANY 120 VOLT LOADS TO THE HIGH LEG, AS THE HIGH LEG TO NEUTRAL WILL READ ABOUT 208 VOLTS.
BE CERTAIN TO NOT CONNECT ANY 120 VOLT LOADS TO THE HIGH LEG, AS THE HIGH LEG TO NEUTRAL WILL READ ABOUT 208 VOLTS.
I agree with you but you had best watch the type of breaker you use if it is connected to B phase. A slash rated breaker is a no go... i.g. 120/240.I will asume that the original service is 240 volt three phase? If you are adding any 240 volt, single phase loads - THAT DO NOT HAVE ANY 120 VOLT EQUIPMENT CONNECTED WITHOUT AN UPSTREAM TRANSFORMER, you can connect one leg of a 240 volt, single phase load to the "high leg." Any equipment that is 240 volt only (with no neutral required) will function just fine using the "high leg", as the high leg to either of the other phases will read 240 volts.
BE CERTAIN TO NOT CONNECT ANY 120 VOLT LOADS TO THE HIGH LEG, AS THE HIGH LEG TO NEUTRAL WILL READ ABOUT 208 VOLTS.
Pete
A three phase panel with a neutral on a high leg system? Is that not forbidden?
Nope.. used to be quite common. It's a fading system though.A three phase panel with a neutral on a high leg system? Is that not forbidden?
Pete
Nope.. used to be quite common. It's a fading system though.
Pete
Last one I did was 5 years ago.
I don't remember one before that.
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