(Rev. 3/10/08)
EPO NO. 39-1
Electric Meters
ELECTRIC METERS
NOTE: Before starting meter testing, contact apartment or mobile home park manager,
then individual tenants to inform them of your purpose and of the fact that their electric
power may be off for a short period of time.
The resources referenced here are EPO, California Code of Regulations, and California
Business and Professions Code.
SPECIAL SAFETY NOTE
There is an inherent danger and possibility of a damaging explosion and/or severe electrical
shock when testing electrical meters. Before an official is assigned to this program, the
official should receive formal classroom training. Inspectors must have “hands-on” training
before testing meters of 240 volts and less.
DMS strongly recommends that officials do not test meters where the service voltage at the
meter exceeds 240 volts between phases.
The utilities have recognized the danger in high voltage testing (voltages exceeding 240
volts). Their practice is to train meter-persons for lengthy periods under close supervision, a
procedure which is not feasible in most weights and measures jurisdictions.
Pre-Test Inspection
Note: EPO Ref. T provides additional information on utility billing rules, meter
complaints, and meter safety.
1. Identification. G-S.1 [1.10]
1.1. Each meter shall have the following information legibly marked on the front of the
nameplate or register: 4027.1, S.6
(a) Manufacturers’ name or trademark, type designation, and serial number.
(b) Voltage rating.
(c) Test amperes (TA).
(d) Maximum amperes (CL) {meter class}.
(e) Watt-hour or disk constant (Kh) {expressed as watt-hours per revolution}.
(f) Register ratio (R ) and multiplier (if 10 or larger).
r
(g) Frequency rating (Hz).
(h) Number of meter stator(s) or elements (polyphase).
(i) Ratio or rating of auxiliary devices.
EPO NO. 39-1
Electric Meters
(Rev. 3/10/08)
EPO NO. 39-2
Electric Meters
2. Type approval.