In the past, design flaws in smart meter units have been known to cause serious fire hazards and spotty performance. This has caused a lot of concern for utilities and manufacturers of smart meters. To prevent problems like this, a new voluntary safety standard – UL 2735 – has been created for electric utility meters.
In the past, meters were tested to UL/CSA 61010-1, as was other Measurement, Control, and Laboratory Equipment. Meter manufacturers are increasingly migrating from UL 61010-1 to UL 2735.
UL 2735 covers:
- Meters rated up to 600V which measure, monitor, record, transmit, or receive electrical energy generation or consumption information
 - Socket mounted plug-in (Type S) utility meters, and non-socket mounted, bottom connected (Type A) utility meters
 - Meters provided with one or two-way communication capabilities by means of carrier signals, telephone, cable, or wireless communication
 - Meters that provide signals, directly or wirelessly, for the control of electrical loads or electrical power generation equipment
 
These construction and performance requirements are included in UL 2735:
Components
- Compliance with relevant component standards
 - Used within their recognized ratings
 - Includes plastics, PCBs, MOVs, wire, and transformers
 
Electrical
- Accessibility of hazardous live parts
 - Electrical spacings over-surface and through-air
 - Isolation of current transformer secondary
 - Endurance of load control switch
 - Single component fault
 
Fire
- Polymeric enclosure flammability
 - Battery protection, charging, placement and replacement
 - Single component fault
 
Mechanical
- Enclosure environmental considerations
 - Enclosure strength and rigidity
 - Access panels
 - Static
 - Impact
 - Drop
 
ANSI C12.1
- Insulation resistance
 - HV line surges
 - Fast transient/burst
 - RF interference
 - RF conducted/radiated emissions
 - Temperature rise
 - Temporary overload
 - Electrostatic discharge
 
Markings
- Environmental suitability
 - Electrical ratings
 - Installation instructions
 - ANSI C12.10 nameplate
 - Permanence and legibility
 
UL 2735 is not yet part of the NRTL Program, however MET Labs is already accomplished in testing to it. Learn more about MET’s highly-regarded testing of meter safety, reliability, and accuracy for manufacturers or utilities.
