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#1
06-08-20, 05:33 PM
Member
Join Date: Jun 2020
Posts: 1

does anyone know why I have 240v reading after the meter but not at the bus bars I checked line 1 and line 2 they both read 120 but not 240 inside the panel

#2
06-08-20, 05:35 PM
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Join Date: Jul 2002
Location: Maryland
Posts: 13,923
Where did you take the readings? Did you cycle any breakers?

#3
06-08-20, 05:51 PM
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Join Date: Nov 2007
Location: United States
Posts: 14,095
They read 120 volts to ground because you have a two-pole breaker that is on. You are reading through a 240v load like a water heater. If you turn off all the two-pole branch circuit breakers you will find out you have one leg that is not hot.

#4
06-08-20, 06:29 PM
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Join Date: Sep 2019
Posts: 1,906
Not sure what you re reading but here is how it works.

Basically you have two 120 volt supplies when measured to Neutral.
So L1 to Neutral = 120 volts and L2 to Neutral = 120 volts.
But the two supplies are 180 degrees out of phase.
So when L1 is at -120 volts, L2 is at +120 volts.
Therefore L1 to L2 = 240 volts

#5
06-08-20, 06:36 PM
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Join Date: Sep 2002
Location: welland ontario
Posts: 7,986
Somewhere between where you are reading 240 volts and the bus bars yo have an open hot connection.

#6
06-09-20, 10:10 AM
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Join Date: Jan 2010
Location: United States
Posts: 9,827
Check voltages on line side of main breaker, then at buss bars on the load side of main breaker. Cycle the main breaker and check again.