TCA22 250A/5A Current Transformers

Current Transformer Socomec TCA22 250A/5A - High accuracy measurement class 1

The Socomec TCA22 250A/5A Current Transformer is a professional measuring transducer designed to convert a high primary current (up to 250A) into a standardised secondary current of 5A, suitable for dataloggers, energy meters and monitoring systems. With its accuracy class 1 and apparent power rating of 3.75VA, this CT (Current Transformer) guarantees reliable and accurate measurement for your photovoltaic, tertiary and industrial installations.

Why use a current transformer in your installations?

Current transformers are essential for measuring high currents safely and accurately:

• Protection of measuring equipment: enables currents of up to 250A to be measured with equipment rated for 5A only (overload protection)
• Signal standardisation: standardised 5A output compatible with all dataloggers and energy meters
• Galvanic isolation: electrical separation between power circuit (primary) and measurement circuit (secondary) for maximum safety
• Cost-saving: avoids the use of expensive, heat-dissipating resistive shunts
• Standards compliance: meets IEC 61869-2 standards for energy metering and billing

Typical applications for the Socomec TCA22 250A/5A transformer

• Residential and tertiary photovoltaic installations: solar production measurement (AC inverter side)
• Energy metering and billing: integration with three-phase meters for consumption/production monitoring
• DIRIS Socomec measurement centres: collection of electrical data (current, power, power factor, harmonics)
• Low-voltage switchboards: monitoring of main feeders and critical circuits
• EV charging stations: metering of energy delivered to electric vehicles
• Heat pumps and large consumers: real-time consumption monitoring
• Commercial and industrial buildings: energy management, consumption drift detection, tariff optimisation, etc.

Technical specifications

Why choose the Socomec TCA22 250A/5A transformer?

1. Accuracy class 1: ideal balance for industrial applications

Accuracy class 1 means that the measurement error is less than or equal to 1% in the current range 5%-120% In :

• ✅ Sufficient for industrial metering: IEC standards accept class 1 for tertiary/industrial billing (class 0.5 or 0.2S for high-precision fiscal metering)
• ✅ Cost-optimised: excellent performance/price ratio vs. class 0.5 (cost overrun +30-50%)
• ✅ Ideal for photovoltaic monitoring: largely sufficient accuracy for monitoring solar production (±1% on 250A = ±2.5A = ±575W @ 230V, negligible compared with weather variations)

Accuracy class table

Classe	Erreur max	Application typique
0,2S	≤ 0,2%	Comptage fiscal haute précision
0,5	≤ 0,5%	Comptage commercial, facturation
1	≤ 1%	Comptage industriel, monitoring PV
3	≤ 3%	Protection, indication approximative

2. 3.75VA apparent power: perfectly suited to dataloggers

The secondary apparent power rating (Sn = 3.75VA) defines the maximum load supported by the CT:

• Maximum secondary load: Z_max = Sn / Is² = 3.75 / 5² = 0.15 Ω
• Compatible with Socomec DIRIS dataloggers: typical input impedance 0.01-0.05 Ω (well below 0.15 Ω)
• Permissible secondary cable length: up to 50m in 2.5 mm² copper (linear resistance 7 mΩ/m → 50m round trip = 0.7 Ω, but device in // reduces total impedance)

Critical rule: never leave the secondary open

If the secondary is disconnected on load (open circuit), the CT behaves like a step-up transformer:

• Secondary overvoltage of up to several kV (danger of electrocution)
• Destructive heating of the magnetic core (saturation)
• Destruction of the transformer

Solution: double short-circuit terminals

The TCA22 has terminals enabling the secondary to be short-circuited before disconnection, eliminating any risk.

3. Overcurrent limiting factor FS 5: robustness against overloads

The FS 5 guarantees that the CT withstands currents of up to 5 x In = 1250A for 1 second without degradation:

• ✅ Mains short-circuit protection: typical fault current 500-2000A absorbed without destruction
• ✅ Transient overloads: motor starting, transformer inrush, inrush currents
• ✅ Durability: no accuracy drift after events

4. 22.5mm aperture diameter: wiring versatility

The22.5mm bore allows the passage of :

• Single-phase cables: up to 70-95 mm² (12-20kW single-phase PV inverter output phases)
• Three-phase cables: 1 phase of 4G16 to 4G35 mm² cable (PAC power supply, VE terminal)
• Copper bars: cross-section up to 20x5mm or 15x10mm (LV panel)

5. Snap-on DIN rail mounting: rapid installation

The TCA22 offers two mounting options:

• Clip-on 35mm DIN rail: tool-free installation/removal in 5 seconds
• Screw fixing lugs: for mounting on a plate or enclosure wall

6. Socomec French manufacturing: quality and reliability

Socomec, founded in 1922 and based in Benfeld (Alsace, France), is a European leader in low-voltage electrical equipment:

• 100% French manufacturing: ISO 9001 certified factory, rigorous quality control
• Recognised expertise: over 100 years' experience in electrical measurement
• Comprehensive range: current transformers from 5A to 5000A, all accuracy classes
• Technical support: full documentation, assistance available

Installation and connection

Critical installation rules

Sizing according to installation power

💡Sizing rule: choose CT with In ≥ 1.2 x rated installation current for safety margin and respect permanent overload 1.2 In.

Checking and maintenance

• Initial visual check: check secondary terminals for tightness (torque 0.8 N.m recommended), absence of bore damage
• Secondary continuity test: measure S1-S2 resistance (typical 0.5-2 Ω depending on model), value > 10 Ω = internal cut-out
• Annual check: check terminal tightness, absence of abnormal heating, clean if dusty environment
• Periodic calibration: for fiscal metering, accuracy class check every 5-10 years (accredited laboratory)

🌍 Integration into the Wattuneed ecosystem

The Socomec TCA22 250A/5A transformer integrates perfectly into Wattuneed monitoring and energy management solutions:

• Photovoltaic production monitoring: precise measurement of output from 8-30 kW single-phase inverters
• Metering of self-consumed energy: calculation of self-consumption rate, grid injection, etc.
• Energy management system (EMS): real-time data for load management (DHW tanks, EV terminals, batteries)
• Anomaly detection: monitoring of consumption drift, identification of malfunctions, etc.
• Tariff optimisation: peak/off-peak consumption monitoring, red day shaving, etc.

🎯 In summary: your benefits with the Socomec TCA22 250A/5A CT

• ✅ Accuracy class 1: reliable measurement ±1%, ideal for PV monitoring and industrial metering
• ✅ Ratio 250A/5A: high power installations 25-60 kW single phase
• ✅ 3.75VA apparent power: compatible with DIRIS control units and COUNTIS meters
• ✅ FS 5 overcurrent factor: supports 1250A peak without degradation
• ✅ Ø22.5mm bore: 70-95 mm² cables or 20x5mm copper bars
• ✅ S nap-on DIN rail mounting: quick installation without tools
• ✅ Enhanced safety: double short-circuit terminals, 3 kV insulation
• ✅ So comec French manufacturing: quality, durability, technical support
• ✅ IEC 61869-2 standards: metering and billing compliance

Turn your photovoltaic installation into a smart production plant with the precise monitoring of the Socomec TCA22 250A/5A current transformer. 📊⚡

Wattuneed, your partner for measured and optimised photovoltaic installations. 🌞📈