Sec. 9.
(a) No
watthour meter that registers at no load (the moving element making more than
one (1) complete revolution when at "no load"), when the applied voltage is
less than one hundred ten percent (110%) of standard service voltage, shall be
placed in service or allowed to remain in service in such condition.
(b) No meter shall be placed in service or
allowed to remain in service that is in any way mechanically defective, has
incorrect constants, or has not been tested for accuracy of measurements and
adjusted, if necessary, to meet the following requirements:
(1) For watthour meters, the following:
(A) Average error not over two percent (2%),
plus or minus.
(B) Error at full
load not over one percent (1%), plus or minus.
(C) Error at light load not over three
percent (3%), plus or minus.
(2) For curve drawing instruments, the
electrical element error shall not exceed two percent (2%), plus or minus, of
full scale indication.
(3) For
integrating demand meters, the following:
(A)
Electric element errors shall not exceed the limits specified for watthour
meters.
(B) For timing element, a
cumulative error shall not be in excess of plus or minus two percent (2%) for
the entire billing period. If the time of day is a factor in the rate schedule,
the timing element, when operating under normal conditions of service, shall
not indicate a difference of more than ten (10) minutes from correct time, and
any incorrect indication of time caused by the temporary loss of utility
service shall be corrected by the utility by the end of the following work
day.
(4) For lagged
demand meters, the following:
(A) For
electromagnetic type, the error shall not exceed two percent (2%), plus or
minus, of full scale indication.
(B) For thermal type, the error shall not
exceed four percent (4%), plus or minus, of full scale indication.
(5) Watthour meters, except
self-contained meters, which are to be used on circuits supplying inductive
load, shall also be tested before installation at one hundred percent (100%) of
manufacturer's rated test current at fifty percent (50%) lagging power factor,
and, if necessary, adjusted so that the error under such conditions will not be
more than two percent (2%), plus or minus. All new meters may be tested by a
meter manufacturer if certified tests are supplied.
(c) Where instrument transformers are used
for metering, the ratio of transformation and phase angle error of the
transformers must be determined before installation, such information being on
file in the office of the public utility.
