ZCS Azzurro HYD 4000 ZP1 Single-phase Hybrid Inverter
4 kW single-phase hybrid inverter from the Easy Power ZP1 series by ZCS Azzurro, the size that matches upgraded 4.5 kW meters. It accepts up to 6,000 W of photovoltaic power and works with HV ZBT 5K 400 V batteries from 5.1 to 20.4 kWh, with charging and discharging power equal to the nominal rating. 4,000 VA EPS, integrated interface protection and DC disconnector, IP65, 10-year warranty.
The Azzurro 1PH HYD 4000 ZP1 is the 4 kW size in ZCS Azzurro’s single-phase hybrid Easy Power series. Compared with the 3 kW model, three key figures change at the design stage: output power, the accepted DC power, which rises to 6.000 W, and the storage charge and discharge power, which follows the nominal rating and reaches 4.000 W.
The right size for a 4,5 kW meter
In Italy, 4 kW has a specific purpose: it is the size matched to homes upgraded to 4,5 kW, very common in houses with a heat pump, induction hob or wallbox. Below that connection power, the inverter’s 4 kW could not be fully used for grid feed-in, so it is better to stay with the 3 kW model; above it, with a 6 kW meter, it makes sense to consider the 5 or 6 kW model directly.
The real reason to move up in size, however, remains the photovoltaic power limit: the 6.000 W of typical DC power is 150% of the nominal rating and allows a PV array significantly larger than the inverter nameplate, with production spread across mornings, evenings and shoulder seasons instead of being concentrated around the midday peak.
Balanced storage, not undersized
The ZP1 series works with HV ZBT 5K high-voltage batteries at 400 V, from 1 to 4 modules for 5,1-20,4 kWh, managed by the integrated BMS. The key figure to note is that the charge and discharge power matches the nominal AC rating: 4.000 W. On many competing platforms, the battery delivers less than the inverter and becomes the bottleneck in island mode; here the system is sized consistently, and the 4.000 VA EPS output with 20 A is genuinely usable.
The series’ common strengths remain: internal interface protection and integrated DC disconnect switch — with 4 kW it is well below the 11,08 kW threshold of CEI 0-21, so no external interface panel is required — EPS switchover in under 10 ms, IP65, less than 25 dB at one meter, onboard LCD display and 10-year warranty.
1PH HYD 4000 ZP1 technical specifications
| Rated AC power | 4.000 W (maximum 4.400 VA) |
| Maximum AC current | 20 A |
| Connection | Single-phase L/N/PE, 220-230-240 V, 180-276 V |
| Typical DC power | 6.000 W |
| MPPT / strings per MPPT | 2 independent / 1 |
| Maximum input voltage | 550 V (activation 100 V, nominal 360 V) |
| MPPT range | 85 - 520 V (full load 185 - 500 V) |
| Maximum current per MPPT | 16 A (absolute 22,5 A) |
| Compatible batteries | HV ZBT 5K, 400 V nominal (300 - 435 V) |
| Number and battery capacity | 1 - 4 modules, 5,1 - 20,4 kWh |
| Max charge / discharge power | 4.000 W |
| Depth of discharge | 0 - 90% programmable |
| EPS output | 4.000 VA, 20 A, 230 V, switchover in under 10 ms |
| Maximum efficiency | 97,8% (EURO 97,1%, MPPT over 99,9%) |
| Internal interface protection | Yes |
| DC disconnect switch | Integrated |
| Communication | RS485, USB, CAN 2.0, Bluetooth; optional Wi-Fi / 4G / Ethernet |
| Operating temperature | -10 / +60 °C (derating above 45 °C) |
| Protection rating | IP65, noise level below 25 dB at 1 m |
| Dimensions (H x W x D) and weight | 470 x 787 x 170 mm, 23,5 kg |
| Warranty | 10 years |
Frequently asked questions
Is 3 kW or 4 kW better?
It depends on two things: the connection power and the size of the PV array. With a 3 kW domestic meter, the 4 kW model cannot feed in its nominal power, so the advantage is reduced to the higher DC power limit, 6.000 W versus 4.500 W. With a meter upgraded to 4,5 kW, the 4 kW model is the natural choice.
How much power does it deliver during a blackout?
The EPS output reaches 4.000 VA with 20 A at 230 V and switches over in less than 10 ms. However, the manufacturer notes that the power actually available depends on the number and type of batteries and on the system status, meaning remaining capacity and temperature: with a single almost discharged module, or at low temperatures, the real value is lower than the nameplate rating.
Which storage system can I pair with it?
Only HV ZBT 5K high-voltage batteries, with nominal voltage of 400 V and permitted range between 300 and 435 V, from one to four modules for a capacity between 5,1 and 20,4 kWh. 48 V lithium batteries cannot be used on this series: for those there is the ZSS HP platform, which is a different product with different features and warranty.
Is an external interface panel required?
No. The interface protection is inside the inverter and, with 4 kW, it remains well below the 11,08 kW threshold above which CEI 0-21 requires an external SPI relay, interface device and test report. For the connection application, the manufacturer’s declaration is sufficient. The DC disconnect switch is also integrated, so no separate DC-side disconnect switch is needed.
Can I use two strings with different orientations?
Yes, the inverter has two independent MPPTs with one string each, so two roof pitches with different orientation or tilt each operate at their own maximum power point. The maximum input current is 16 A, with an absolute permitted current of 22,5 A, and the MPPT range is from 85 to 520 V. The configuration must still be checked using the ZCS Azzurro online configurator.