Current through Register Vol. 54, No. 38, September 21, 2024
(a) No
watthour meter which has an incorrect register constant, test constant, gear
ratio or dial train, or which "creeps," that is, registers upon no load, may be
placed in service or allowed to remain in service without adjustment and
correction. A meter in service creeps if, with the load wires disconnected, the
moving element makes one complete rotation in 5 minutes or less.
(b) For the purpose of this section, the term
"light load" means not less than 10%, nor more than 15%, of the rated test
current of the meter. The term "heavy load" means not less than 75%, nor more
than 100%, of the rated test current of the meter.
(c) No watthour meter which has an error in
registration of more than 2.0% at light load or heavy load may be placed in
service or allowed to remain in service without adjustment. If, upon
installation, periodic or other tests, a watthour meter is found to exceed
these limits, it shall be adjusted or removed from service.
(d) A public utility shall maintain records
of service watthour meters. The record for a meter shall identify the
manufacturer, type, rating, year of purchase, year and location of the present
installation in service, the year of the last test and the reason for the test,
the registration accuracy recorded as found before adjustment and the
registration accuracy recorded as left upon the completion of the
test.
(e) A public utility shall
make periodic tests of its watthour meters in service as follows:
(1) Two and three-wire single-phase and
network-induction-type meters, up to and including 50 amperes rated test
current, shall be tested at least once in each of the following periods:
(i) If manufactured prior to January 1, 1940,
and the meters are not Class I and II temperature compensated and are not
equipped with surge-proofed magnets or surge shields-3 years.
(ii) If the meters are Class I and II
temperature compensated and are equipped with surge-proofed magnets or surge
shields-15 years.
(iii) If
manufactured since January 1, 1959, and the meters are Class I and II
temperature compensated and are equipped with surge-proofed magnets, surge
discharge gaps and a shielded magnetic bearing system-20 years.
(2) An an alternative, meters
described in paragraph (1)(ii) and (iii) shall be tested according to
statistical procedure in Section 8.1.8.6 of the current edition of the
ANSI C-12 Code for Electric Meters, Fifth Edition.
(i) Groups which meet the accuracy
requirements of the applied statistical procedure shall continue in service
without test or adjustment until a subsequent annual statistical analysis
indicates the need for corrective action or the Commission on its own motion
requests retest of either entire groups or individual meters. Test results
affecting billing shall be furnished to customers without charge.
(ii) Groups which fail to meet the accuracy
requirements of the applied statistical procedure are subject to one of the
following immediate corrective measures:
(A)
Meters within the group affected shall be removed from service upon
notification to the Commission and in compliance with a program acceptable to
the Commission. A customer's accounts billed according to registration by these
meters shall be retained by the public utility from 2 years prior to discovery
of registration error until date of meter removal or adjustment. Test results
affecting billing shall be furnished to customers without charge and shall be
retained by the public utility for at least 2 years after the meter is
retired.
(B) Meters within groups
affected shall be placed on an accelerated program of testing and maintenance
until subsequent annual statistical analysis indicates that the affected groups
again meet the accuracy requirements of the statistical testing program.
Records of customer accounts and of test results affecting billing shall be
retained by the public utility and furnished to customers under clause
(A).
(3) Two
and three-wire single-phase and network-induction-type meters, of over 50
amperes rated test current, shall be tested at least once every 8
years.
(4) Single-phase meters
connected through current transformers or current and voltage transformers
shall be tested as follows:
(i) Meters without
surge-proof magnets, at least once every 8 years.
(ii) Meters with surge-proof magnets, at
least once every 16 years.
(5) Self-contained polyphase meters shall be
tested as follows:
(i) Meters without
surge-proof magnets, at least once every 8 years.
(ii) Meters with surge-proof magnets, at
least once every 16 years or according to statistical procedures as described
in paragraph (2).
(6)
Polyphase meters connected through current transformers or current and voltage
transformers shall be tested as follows:
(i)
Meter without surge-proof magnets, at least once every 8 years.
(ii) Meters with surge-proof magnets, at
least once every 16 years.
(f) An alternating current watthour meter
shall be tested and adjusted before installation for correct registration
within ±2%, at a power factor of approximately 50% and 100% at rated
test current. When in service, meters not tested and adjusted before
installation shall be tested and adjusted to the percent accuracy specified as
soon as the circumstances permit, or shall be removed from service.
(g) A service watthour meter installed shall
be tested for accuracy by the public utility prior to its installation, or
shall be so tested within 90 days after its installation. It shall also be
inspected by the public utility for proper connection, mechanical condition and
suitability of location within 90 days after installation.
(h) A service watthour meter which is removed
from service shall be tested for "as found" registration accuracy.
The provisions of this §57.20 amended under the
Public Utility Code,
66 Pa.C.S. §
§
501,
1501 and
1504.
This section cited in 52 Pa. Code §
57.22 (relating to request tests
and fees); 52 Pa. Code §
57.23 (relating to general testing
conditions); 52 Pa. Code §
57.24 (relating to adjustment of
bills for average meter error); and 52 Pa. Code §
57.254 (relating to advanced meter
standards).
