Electricity meter | Energomera CE 303 S31 746 JAVZ | 380V 100A

Energomera CE303 S31 746-JAVZ is an electronic three-phase multi-tariff meter designed for direct measurement of active and reactive electrical energy in 3×230/400 V networks.

The model has a base current of 5 A and a maximum current of 100 A. This means it connects directly to the power circuit without current transformers, provided that the calculated site load remains within the meter rating and project requirements.

🔎 Meaning of CE303 S31 746-JAVZ

• CE303 — series of three-phase electronic active and reactive energy meters;
• S31 — enclosure designed for installation in an electrical panel;
• 7 — accuracy class 1.0 for active energy and 1.0 for reactive energy;
• 4 — 230 V phase voltage and 400 V line voltage;
• 6 — 5(100) A current rating;
• J — optical port;
• A — RS-485 interface;
• V — terminal-cover opening detection;
• Z — extended set of measured and stored parameters.

🔌 Direct connection up to 100 A

The meter has a current rating of 5(100) A:

• 5 A — the base current used for standardising meter characteristics;
• 100 A — the maximum continuous current passing through the meter.

This is a direct-connected meter: the power conductors connect directly to its terminals without current transformers.

The model is suitable for private houses, shops, offices, workshops, small industrial premises and other sites with a three-phase supply, provided the load current complies with the electrical design.

📊 Active and reactive energy

The CE303 meters two types of electrical energy:

• active energy — energy converted into useful work, lighting or heat;
• reactive energy — energy associated with motors, transformers and other equipment containing coils or capacitors.

Reactive-energy metering is particularly important for industrial facilities, pumping installations, refrigeration equipment, machinery and other sites with numerous electric motors.

🕒 Multi-tariff metering

The meter supports up to four tariffs. Electrical energy can be recorded separately by time of day, such as daytime, night-time or another tariff zone established by the electricity supplier.

The internal clock and tariff schedule must be configured in advance. Actual use of multi-tariff operation depends on the rules of the local electricity supplier.

📈 Load profile

The meter can store a load profile — a history of electricity consumption over defined time intervals.

This information helps users to:

• identify peak-consumption periods;
• compare daytime and night-time loads;
• detect unusual consumption spikes;
• analyse equipment operation;
• monitor tenants or separate areas of a property;
• plan reductions in peak load.

📐 Monitored network parameters

Depending on configuration and firmware, the CE303 can measure and display:

• voltage on each phase;
• current on each phase;
• electrical-network frequency;
• active power;
• reactive power;
• apparent power;
• power factor;
• angles between phase-voltage and current vectors;
• direction of energy flow;
• accumulated active and reactive energy.

Power factor indicates how efficiently the site uses the supplied electrical energy. A value close to 1 normally represents more efficient load operation.

📡 Optical port and RS-485

The model provides two communication methods:

• optical port — for local reading and configuration with a dedicated optical probe;
• RS-485 — a wired industrial interface for connection to a controller, computer, converter or AMR system.

AMR is an automated electricity-metering system that collects readings from meters and sends them to the supplier’s or facility operator’s software.

The letter A in the JAVZ designation confirms RS-485, but this modification does not include an integrated GSM, GPRS or PLC modem.

Internet or mobile-network transmission requires a compatible external modem, controller or interface converter.

🔐 Terminal-cover opening detection

The V function detects opening of the terminal cover. The event can be recorded in the internal log and used to identify unauthorised access to the meter connections.

This is an electronic addition to the physical seal. It does not remove the requirement for physical sealing in official commercial metering.

🗂️ Event logs and diagnostics

Depending on the firmware version, the meter may store events associated with:

• opening of the terminal cover;
• changes to settings;
• loss and restoration of power;
• network-parameter violations;
• reverse energy flow;
• internal-clock errors;
• communication failures;
• magnetic-field exposure when the relevant sensor is fitted.

The exact contents of the logs must be confirmed from the passport, firmware version and configuration software.

🏠 Applications

• private houses with a three-phase supply;
• shops and retail premises;
• offices and administrative buildings;
• workshops and service centres;
• small industrial premises;
• pumping and engineering installations;
• internal monitoring of tenants;
• technical metering of separate circuits;
• commercial metering with valid verification and supplier approval.

🧭 Main or check metering

Technically, the CE303 is a fully functional multi-tariff meter and is not limited to internal check metering.

For official billing with an electricity supplier, confirm:

• that the model appears in the permitted register;
• valid state metrological verification;
• compliance with the approved metering arrangement;
• correct tariff programming;
• requirements of the electricity supplier;
• availability of seals and a commissioning certificate.

🔧 Installation requirements

• completely isolate the electrical installation;
• verify absence of voltage;
• check the wiring diagram on the cover or in the passport;
• correctly connect phases L1, L2, L3 and neutral N;
• observe the input and output direction of every phase;
• use conductors of suitable cross-section;
• tighten the terminals to the specified torque;
• do not allow insulation to enter the contact clamp;
• install an appropriate incoming circuit breaker;
• check phase sequence;
• configure the date, time and tariffs;
• test communication through RS-485 or the optical port;
• close and seal the terminal cover.

Installation and programming must be carried out by a qualified electrician. Live connection is potentially fatal and may damage the meter.

⚠️ Current limitation

The 100 A value is the meter’s maximum current rating, not a recommendation to operate the circuit continuously at its limit.

Cable cross-section, circuit-breaker rating, installation method and permitted power must be determined by the electrical design. When the calculated current exceeds 100 A, a transformer-operated meter with current transformers is required.

📦 Package contents

• Energomera CE303 S31 746-JAVZ meter;
• terminal cover;
• passport or operating manual;
• form containing the serial number and verification information;
• factory packaging.

The optical probe, RS-485 converter, modem, circuit breaker, installation cable and metering cabinet are purchased separately unless explicitly stated otherwise by the seller.

✅ Key advantages

• direct connection up to 100 A;
• 3×230/400 V three-phase network;
• active and reactive energy metering;
• accuracy classes 1.0/1.0;
• up to four tariffs;
• load profiles;
• electrical-network parameter monitoring;
• optical port;
• wired RS-485 interface;
• terminal-cover opening detection;
• extended set of measured parameters;
• AMR integration capability;
• official verification interval for the S31 enclosure of up to 16 years;
• four-year manufacturer warranty.

⚠️ What to check before ordering

• complete CE303 S31 746-JAVZ designation;
• 5(100) A current rating;
• 3×230/400 V voltage rating;
• manufacturing date;
• initial verification date;
• verification validity in Uzbekistan;
• availability of passport and certificate;
• firmware version;
• RS-485 communication protocol;
• supported configuration software;
• availability of load profiles;
• contents of event logs;
• number of tariffs;
• communication-equipment package;
• eligibility for official metering;
• warranty applicable to the supplied batch.

⚠️ Important: this is the JAVZ version, not JGVZ. The letter A indicates RS-485, whereas G indicates GSM/GPRS. Therefore, the CE303 S31 746-JAVZ has no integrated GSM modem.