Metrel MI 2885 and MI 2883: Class S Power Quality

Short answer

Metrel's MI 2885 Master Q4 and MI 2883 Energy Master are portable power quality analyzers that meet Class S of IEC 61000-4-30. The MI 2885 is aimed at diagnostics, with four voltage channels, four current channels and transient recording; the MI 2883 is intended for long-term energy logging. Class S is suited to studies and diagnostics; to verify compliance for a third party, Class A is usually required.

What these analyzers are

The MI 2885 Master Q4 and the MI 2883 Energy Master are portable three-phase power quality analyzers from Metrel. Both meet Class S of IEC 61000-4-30 (Metrel declares 0.1 % for the MI 2885). They share the same compact format (230 × 140 × 80 mm and about 1 kg), a color display with quick-setup buttons and an 8 GB microSD card expandable to 32 GB. They are complemented by the PowerView3 software for analysis and automatic reports.

The difference is not in size but in purpose:

	MI 2885 Master Q4	MI 2883 Energy Master
Orientation	Diagnostics and troubleshooting	Long-term energy logging and efficiency
Channels	4 voltage and 4 current	3 voltage and 4 current
Voltage range	0 to 1000 Vrms, CAT III / 1000 V	0 to 1000 Vrms, CAT III / 1000 V
Transients	Yes, 49 kS/s on 8 channels	Not stated on the product page
Capture	7 configurable triggers	Programmable alarms (up to 7)

Class A and Class S: what each is for

IEC 61000-4-30 establishes two performance classes:

Class A: the most demanding. Uncertainty is low, data aggregation and time synchronization are strictly defined, and results are comparable between manufacturers. It is used when the measurement may act as arbiter between two parties.
Class S: intended for statistical studies, energy audits and troubleshooting, where the analysis matters more than the legal value of each figure.

This distinction defines the use, not the quality of the instrument. An energy audit or the identification of the causes of process trips can be handled with Class S. A power supply quality compliance check for a utility normally calls for Class A, such as that of the Metrel MI 2892 and MI 2893. Find out which class the recipient of the report requires before choosing the equipment.

What they measure

According to the product pages:

Voltage and current TRMS, peaks and crest factor.
Active, reactive and apparent power, using the IEEE 1459 formulation.
Harmonics and interharmonics up to the 50th order, with THD and TDD.
Flicker (IEC 61000-4-15), unbalance and power factor.
Supply events: interruptions, voltage dips (sags) and swells.
Active, reactive, generated and consumed energy.
EN 50160 analysis, with signalling voltages and interharmonics.
Programmable alarms and temperature measurement.
Variable frequency drives (5 to 120 Hz) and 400 Hz systems, on the MI 2885.
Efficiency of photovoltaic inverters, on the MI 2885.

Clamps are recognized automatically, with range selection on the instrument itself.

When each one is the right choice

MI 2885: when the problem is an intermittent phenomenon that has to be caught: drive trips, dips that stop a line, starting currents or switching transients. The triggers and transient recording are built for that.
MI 2883: when the goal is to measure consumption and its profile over weeks, find demand peaks, no-load consumption, unbalance or the efficiency of an installation.

In both cases a useful recording lasts days: a full week that includes the production cycles is the reasonable minimum. See the guide on the power quality analyzer and the one on power quality in industry.

How to read a Class S recording

Verify the recording conditions: connection, clamp ratio and instrument transformer ratios, period, and plant operation during the period.
Examine the events and relate them to what happened in the process: starts, switching operations, storms.
Review harmonic distortion and unbalance, and compare with the agreed criterion (EN 50160 for supply, IEEE 519 for the point of common coupling).
For energy, read the daily profile: baseline, peaks and their relation to the shifts.
State the conclusions together with the instrument class: a Class S report describes, guides and diagnoses; it does not replace a Class A verification when one is required.

What question each recording answers

The choice of instrument and recording period depends on the question to be answered:

Does my voltage comply with the standard? A recording of one full week, evaluated against EN 50160, and Class A if a third party will receive it as evidence.
Why does the drive trip or the line stop? Continuous recording with alarms and waveform triggers on voltage and current, so that the instrument captures the time window of the event.
How much does the energy cost and when is it consumed? Energy logging over several weeks, with a daily profile, maximum demand, power factor and no-load consumption.
Is my plant injecting harmonics into the grid? Recording at the point of common coupling with comparison against IEEE 519, taking current and voltage at the same point.
What happens when a motor starts or a transformer is energized? Recording of the inrush current with sufficient time resolution.

In every case, the report must state the conditions: what was operating, at what load and in what network configuration. Without that context the numbers cannot be interpreted or reproduced.

Precautions

The clamps must match the actual current range; an excessive range loses accuracy.
Phases and polarity: a wrong order gives wrong power and power factor values.
Time synchronization: needed if several measurement points are going to be compared.
Safety: connecting to energized panels requires qualified personnel, PPE and a procedure.

Power quality recording on request

Do you need this test? We perform it for you: depending on your case we recommend the right test and equipment and include it in the quotation. That way you get the test your case really needs, without paying for extra tests. Field work is done in Colombia, or elsewhere on request.

Learn about our testing and commissioning service and request your quotation through the form.

References

Metrel, product pages of the MI 2885 Master Q4 and the MI 2883 Energy Master (metrel.si).
IEC 61000-4-30, Electromagnetic compatibility (EMC) – Part 4-30: Testing and measurement techniques – Power quality measurement methods.
EN 50160, Voltage characteristics of electricity supplied by public electricity networks.
IEEE Std 1459, Definitions for the Measurement of Electric Power Quantities Under Sinusoidal, Nonsinusoidal, Balanced, or Unbalanced Conditions.

Frequently asked questions

What is the difference between Class A and Class S in IEC 61000-4-30?

Both define how to measure power quality parameters. Class A imposes the lowest uncertainty and the strictest requirements for aggregation and time synchronization; Class S allows less strict requirements and is intended for statistical studies, diagnostics and comparisons where the measurement is not the arbiter of a contractual dispute.

Is a Class S analyzer suitable for an EN 50160 report?

To analyze the behavior of the voltage and see whether it departs from the limits of the standard, yes: according to Metrel, both models offer EN 50160 analysis. If the report must serve as proof of compliance to the utility or in a contract, check which class the recipient requires; in that case Class A is the usual choice.

What is the difference between the MI 2885 and the MI 2883?

According to Metrel, the MI 2885 Master Q4 is presented as a diagnostic tool, with four voltage channels, seven waveform capture triggers and transient recording; the MI 2883 Energy Master is designed specifically for energy logging and efficiency calculations, with three voltage channels and four current channels.