Northwest Lineman College
METER TECHNICIAN CERTIFICATION PROGRAM
CURRICULUM SAMPLE EXCERPTS
Metering
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2:28
Voltmeter Method 1.
Using a standard voltmeter, the meter base can be checked for back feed, short circuits, open circuit, or closed customer breaker.
With the source side energized and the customer’s disconnect open, proper voltage to the meter socket can be confirmed with the following:
Meter Testing and Installation
• A voltage reading of 120 volts between S1 and neutral; • A voltage reading of 120 volts between S2 and neutral; and
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• A voltage reading of 240 volts should be read between S1 and S2
S1
Energized Source (Line)
S1
S2
120 A V
V
V
OFF
Customer Disconnect Open
V
Customer Disconnect Open Load L1
18
S2
240
A
OFF
Energized Source (Line)
NORTHWEST LINEMAN COLLEGE
Load L2
L1
L2
Self-Contained Meters | CHAPTER ONE
2. With the customer’s disconnect open, a voltage reading of zero between L1 and L2 and the neutral will confirm that the service is not back fed from another source.
S1
Source (Line)
S2
zero reading
0 A V OFF
V
Customer Disconnect Open Load L1
L2
Testing for back feed
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© 2016 Northwest Lineman College Published February 2016