For the purpose of establishing uniformity and of providing power quality guidelines to its customers, LADWP adopts the range of service voltages in use by the American National Standards Institute for Electric Power Systems and Equipment C84.1-1989.
In regards to voltage sags, swells, or transient impulse disturbances, there are currently no recognized standards. However, based on experience and shared industry knowledge, guidelines are presented that have been found to resolve many issues.
The Power Quality Group should be notified at (213) 367-6080, if voltages are found to persist outside of the voltage ranges specified.
ANSI Standard C84.1
The American National Standards Institute (ANSI), which coordinates and administers the U.S. standards and conformity assessment system, provides the Service Voltage Ratings (60 Hz) for Electric Power Systems and Equipment in Table I below.
The LADWP uses the term "Service Voltage" to define the Voltage at the point where our electrical system and the customer's are connected. There are two distinct ranges defined for service voltage listed in Table I below. First is the Desirable Range, which requires that occurrences of service voltage outside of this range should be infrequent. Second is the Acceptable Range, which encompasses occurrences outside of the Desirable Range that may result from practical design or operating conditions and that should be limited in extent, frequency, and duration.
|
Nominal Service Voltage |
Desirable Range |
Desirable Range Normalized to 120 Volts |
Acceptable Range |
Acceptable Range Normalized to 120 Volts |
|---|---|---|---|---|
|
120 |
126-114 |
N / A |
127-110 |
N / A |
|
208 |
218-197 |
126-114 |
220-191 |
127-110 |
|
240 |
252-228 |
126-114 |
254-220 |
127-110 |
|
277 |
291-263 |
126-114 |
293-254 |
127-110 |
|
480 |
504-456 |
126-114 |
508-440 |
127-110 |
|
2400 |
2520-2340 |
126-114 |
2540-2280 |
127-114 |
|
4160 |
4370-4050 |
126-114 |
4400-3950 |
127-114 |
|
4800 |
5040-4680 |
126-114 |
5080-4560 |
127-114 |
|
13800 |
14490-13460 |
126-114 |
14520-13110 |
127-114 |
|
34500 |
36230-33640 |
126-114 |
36510-32780 |
127-114 |