High Leg of 3 phase panel reading 124 volts

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Tim007

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Hello. I'm checking a 3 phase panel and I have the following readings.

A - 124 volts
B(high leg)- 124 volts
C - 123 volts
All readings taken from leg to neutral
Do you have any idea why I could be getting these bad readings?
 
The voltages you've posted are not from a 3 phase, 4 wire Delta system with a high leg. They're indicative of a 208Y/120 volt system.
 
Tim007 said:
Hello. I'm checking a 3 phase panel and I have the following readings.

A - 124 volts
B(high leg)- 124 volts
C - 123 volts
All readings taken from leg to neutral
Do you have any idea why I could be getting these bad readings?
Click to expand...
What are the L-L voltages?
 
roger said:
What are the L-L voltages?
Click to expand...
A/C - 215 volts
A/B - 214 volts
B/C - 214 volts

It's a store and he wants to have a 3 phase sub panel wired for a 208/230 volt rated compressor.
He currently has the normal 120 volt outlets and 240 volt outlets wired. I'm confused on how He hasn't ruined the equipment running on the 240 volt outlets when they are reading lower voltage.
To have that sub panel wired for the 208/230 volt 3 phase compressor as it stands now would not work if I'm understanding correctly. Well it would work but could eventually cause an issue with the compressor... right?
 
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Tim007 said:
A/C - 215 volts
A/B - 214 volts
B/C - 214 volts

It's a store and he wants to have a 3 phase sub panel wired for a 208/230 volt rated compressor.
He currently has the normal 120 volt outlets and 240 volt outlets wired. I'm confused on how He hasn't ruined the equipment running on the 240 volt outlets when they are reading lower voltage.
To have that sub panel wired for the 208/230 volt 3 phase compressor as it stands now would not work if I'm understanding correctly. Well it would work but could eventually cause an issue with the compressor... right?
Click to expand...

No, as stated,you have a 208/120 wye system. A compressor rated for 208 is perfectly fine.

A lot of 240V equipment will tolerate a 208V supply, especially when the voltage is on the high side like this one. It depends on the type and design of said equipment.
 
Tim007 said:
A/C - 215 volts
A/B - 214 volts
B/C - 214 volts

It's a store and he wants to have a 3 phase sub panel wired for a 208/230 volt rated compressor.
He currently has the normal 120 volt outlets and 240 volt outlets wired. I'm confused on how He hasn't ruined the equipment running on the 240 volt outlets when they are reading lower voltage.
To have that sub panel wired for the 208/230 volt 3 phase compressor as it stands now would not work if I'm understanding correctly. Well it would work but could eventually cause an issue with the compressor... right?
Click to expand...
You don't have a high leg Delta. Those readings are a 208/120V. they are a little high but within tolerance.
 
Ok. Thank you for your help in this matter. I wanted to double check to make sure.
 
208V is nominal voltage +/-- a certain percentage of the nominal is the actual voltage, site voltage, service voltage.

The same applies to other voltages.
 
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