Weco ESX-3K3kW single-phase hybrid inverter for 48V batteries

Overview

The ESX-3K is the 3kW model of WeCo's single-phase hybrid range for 48V lithium batteries. Despite its rating it accepts up to 10kW of PV on two MPP trackers, so a larger array can charge the battery while the inverter supplies 3kW to the house. Battery current is 75A in both directions, backup output carries the full 3kW with 200% for 10 seconds, and natural cooling keeps it silent. A generator input and parallel operation of up to nine units allow later expansion.

• 3–6kW, 230V single-phase output
• 40–60V battery, up to 135A charge/discharge
• 2 MPPT, 550V max., 18A per tracker
• Up to 10kW PV on every model
• Generator input, up to 9 units in parallel
• IP65, CEI 0-21 certificates published

How it works

The ESX range covers 3, 3.6, 4.6, 5 and 6kW and connects PV, a low-voltage lithium battery, the grid, an EPS output for critical loads and a generator. The battery side works from 40 to 60V with 58.4V maximum charge voltage and WeCo-CAN communication; charge and discharge current is 75A on the 3 and 3.6kW models, 110A on the 4.6 and 5kW and 135A on the 6kW.

Two MPP trackers, one string each, operate from 70 to 540V with 90V start-up and 550V maximum Voc, and accept up to 10kW of PV on every size, so even the 3kW model can take a large array. The EPS output supplies rated power with 110% for 60s and 200% for 10s, switching over in 10ms on average. Grid bypass is 7.5kW/34A on the 3 and 3.6kW models and 9kW/41A from 4.6kW.

Key features

In automatic mode the inverter covers the loads first, charges the battery with surplus and exports the rest, or limits PV output when export is disabled; off-grid it stops discharging at the set off-grid DoD. With a generator connected, generator, battery and PV share the load. Two DI, two DO, a DRM port, USB and a Wi-Fi/LAN dongle are provided; the 3–5kW models are naturally cooled and the 6kW uses a fan.

Installation and compatibility

The ESX is IP65 for indoor or outdoor wall mounting, preferably sheltered from sun, rain and snow, at a recommended 1500mm from floor to the base of the inverter; WeCo excludes outdoor sites within 500m of the sea. The supplied CT measures grid current, a digital meter is optional, and both must sit close to the main meter. External battery breakers of 100A (3–3.6kW), 150A (4.6–5kW) or 175A (6kW) at 80V DC are specified.

For parallel systems the inverters are linked through the 10-pin PARA connector with DIP-switch termination, and parallel mode is enabled in the NooR app. Supported earthing systems are TN-S, TN-C, TN-C-S and TT. The datasheet lists CE, EMC, IEC 61000, IEC 62109, UK G and CEI 0-21, and WeCo publishes CEI 0-21 certificates for the ESX 3–6kW and for the ESX with its 16K0-LV battery.

Monitoring and settings

Commissioning, settings and firmware updates use the NooR app with the Wi-Fi module: the installer creates the plant, scans the logger and sets parameters in the advanced menu. The inverter warranty is five years, extendable to ten when a WeCo lithium storage system is connected and the product is registered.

Questions and answers