Power monitoring devices · Multifunction power meters and power-quality monitors, what to record for each goal, 15-minute interval data, harmonics and waveform capture, CT and PT inputs, ANSI C12 accuracy classes, Modbus and BACnet
A power monitoring device is a panel- or DIN-mounted electronic instrument that measures voltage, current, power, energy and power-quality quantities such as harmonics on one or more circuits through current and potential transformers, stores interval and event data, and sends them to a monitoring or building management system. Ask three things first: which uses the data must serve (billing allocation, diagnostics, power quality), which quantities, intervals and accuracy class that requires, and how the device connects to CTs, PTs and the data network.
Electronic power monitors for facilities and switchboards: multifunction power meters with logging, power-quality monitors and branch-circuit monitoring devices with communication outputs. Utility billing energy meters (see energy meter), instrument transformers sold alone, portable power analysers and protective relays are outside this page.
CNFX editorial research · Sources checked October 12, 2026 · 4 sources
The FEMP Metering Best Practices Guide (Release 3.0, 2015) Table 3-3 lists electric data by goal: demand and energy for cost allocation, load aggregation and utility rate analysis; amps, volts, reactive power and harmonic data, at a rate set by waveform capture needs, for power quality, which it says is appropriate to critical equipment; and 15-minute or shorter intervals for energy system diagnostics. [1]
It describes advanced solid-state meters as using integrated circuits with current and voltage transformers, on-board memory and communications, recording average demand over a set interval, which the guide gives as 15 minutes to match utility billing, and offering diagnostic capability that mechanical and electro-mechanical meters lack. [1]
Editorial calculation: the guide's example of 50 meters reporting 15-minute data gives 4,800 data points a day and over 1.7 million a year; a device logging 10 quantities at 1-minute intervals would produce 14,400 values a day on its own, so size storage and the data system to the quantities and intervals you actually need. [1]
Give the supplier the monitoring goals, number of circuits, system voltage and wiring (single-phase, three-phase three- or four-wire), CT and PT ratios, quantities to record (energy, demand, power factor, harmonics, events, waveforms), logging interval and storage, accuracy class, communication protocol and network, display needs, mounting, auxiliary supply and quantities.
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Check inputs, accuracy and communications
The guide notes that electric meters require current transformers, potential transformers and safety switches, either built in or specified separately; that accuracy classes for electric meters are defined in ANSI/NEMA C12.1 and C12.20; that accuracy may be stated as a percentage of reading or of full scale, which give different errors at low load; and that calibration should be traceable to NIST. [1]
For data output it lists calibrated pulses for building-level meters and protocols such as Modbus, LonWorks or BACnet for more advanced features, with data stored at the meter or time-stamped by a data acquisition system and retrieved at least daily. It advises against buying a meter that captures more data than you can process, and says electrical metering work should only be done by qualified staff under NFPA 70. [1]
Editorial note: accuracy of the whole measurement depends on the CTs as well as the meter; ask for the combined accuracy with the CT class you will install.
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Compare multifunction, branch-circuit and power-quality devices
SATEC's PM135 is a three-phase multifunction meter with Class 0.5/0.5S active-energy accuracy to ANSI C12.20 and IEC 62053-22 and Class 0.2 to IEC 61557-12, direct voltage inputs of 15–828 V AC line to line, 25/50/60/400 Hz measurement at 128 samples per cycle, harmonics to the 40th order, 5 A or 1 A CT inputs or 40 mA inputs for its own high-accuracy sensors (100–3,000 A), RS485 with Modbus RTU, DNP3.0 and IEC 60870-5-101/104, and up to 16 I/O. [2]
For branch-circuit monitoring, SATEC's BFM-II meters up to 18 three-phase or 54 single-phase circuits on a DIN rail, at Class 0.5S/0.5 for revenue billing of tenants, sampling at 64 samples per cycle with harmonics to the 25th order, with RS485 and Ethernet built in, BACnet, Modbus RTU and DNP3.0 protocols, up to 72 digital and 16 analogue I/O, and current inputs for 5–3,000 A sensors or Rogowski flex clamps. [3]
For power quality at substations, SATEC's PM180 is certified by NMI as Class A (Edition 3) to IEC 61000-4-30, meters at Class 0.2/0.2S to ANSI and IEC 62053-22, records transients at 1,024 samples per cycle, produces EN 50160 and IEEE 1159 reports, supports IEC 61850, IEC 60870-5-101/104, DNP3 and Modbus, and works as an IEEE C37.118.1 phasor measurement unit with total vector error below 0.05%. [4]
Editorial calculation: one BFM-II in place of separate meters for 54 single-phase tenant circuits cuts the device count from 54 to 1; check that the 18 three-phase / 54 single-phase limit covers the panel with spare ways. [3]
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Find power monitoring device manufacturers
The companies in the manufacturer list below show this product on their own websites. Confirm the legal seller, factory and scope for your order.
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Trace the device components
This is a functional reference built from the sources cited; it is not one maker's design.
Fill the specification fields with values for your installation
A power monitoring device quotation needs values for your installation. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
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Compiled and source-reviewed by the CNFX editorial team.
Published product pages show what a company offers, not tested performance. Confirm the legal seller, factory and scope for your order. How we source and review
· Page last updated 13 October 2026
Buyer questions
What data does power-quality monitoring need?
The FEMP guide suggests amps, volts, reactive power and harmonic data, sampled at the rate waveform capture requires, for critical equipment. [1]
Which standards define electric meter accuracy classes?
ANSI/NEMA C12.1 and C12.20, according to the FEMP guide. [1]
What interval do advanced meters record?
The guide gives 15 minutes to match utility billing intervals, with shorter intervals for end-use diagnostics. [1]
What accuracy class do power monitoring meters carry?
SATEC lists Class 0.5/0.5S (ANSI C12.20, IEC 62053-22) for its PM135 and BFM-II, and Class 0.2/0.2S for its PM180 power quality analyzer. [2][3][4]
Sources and what still needs a direct check
Sources checked 2026-10-12. The FEMP guide is US federal guidance on metering programmes; it does not rate individual products. Specifications for your order must come from the supplier's data sheets and test certificates.
