I'm getting a high voltage on line1 to ground and Line3 to ground

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kca

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Philippines
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Electrical Engineer
I'm getting a rating of the following:

229 Volts on Line 1 to Ground
91V on Line 2 to Ground
230V on Line 3 to Ground

on a 240-volt, three-phase system, Y connection. Is this a problem?
 
CoolWill said:
Yes, sounds like a problem. Are these readings with the system unloaded?
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the system is loaded, also when the load side ground tap to line side ground. then we energize the equipment the breaker will trip. is there a mis-connnection on the panel?

there's also a ct type on line 1 and line 3.
 
The load side and line side ground wires are supposed to be connected together. If this causes the breaker to trip you have a strange problem.

Maybe you can sketch up what you have for us.

Is the breaker that is tripping on the primary side?
 
kca said:
the system is loaded, also when the load side ground tap to line side ground. then we energize the equipment the breaker will trip. is there a mis-connnection on the panel?

there's also a ct type on line 1 and line 3.
Click to expand...
I don't understand what you are saying here. Can you try again with some more details?
 
You mentioned this is a 240 Volt Wye system. Is the "Y" center point grounded? Or is this a three wire 240 Volt "Y"? The reason I ask is the voltages clearly indicate a problem. Most likely is Line #2 being all most grounded.

Would you please give a full list of voltage and current checks, along with a schematic of the wiring?
 
hillbilly1 said:
Blown fuse on line two, or XO not bonded. Need more info such as line to line voltage.
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My first thought, maybe not necessarily blown fuse but open circuit in the supply line on the one phase conductor. What voltage OP is reading is back feed from other lines through loads.
 
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