Three-Phase Photovoltaic AC Protection Panel QAC 75/95 kW
CEI 0-21 interface panel for photovoltaic systems from 75 to 95 kW on one inverter, rated current 160 A at 400 V. Includes SPI, 140 A-AC3 DDI contactor, IMTD 4x160 A-10 kA with DDR backup, inverter protection IMT, SPD surge arrester and fuse holders dedicated to SPI power supply and measurements, in IP66 enclosure with 140 modules. Supplied with single-line diagram, Di.co and SPI test report.
The Icierre QAC 75/95 kW interface panel is the 160 A size in the low-voltage interface series, intended for commercial and industrial photovoltaic systems from 75 to 95 kW served by a single inverter. It houses in an IP66 enclosure with 140 DIN modules the entire chain required by CEI 0-21 for connecting a generator of this size: interface protection, interface device, main protection with backup and dedicated inverter protection.
The last size that remains in low voltage
Within the regulatory framework of ARERA TICA, the operating threshold between low and medium voltage is 100 kW: up to that value, the connection is normally in LV and CEI 0-21 applies; beyond the ordinary reference, it becomes medium voltage with CEI 0-16, delivery substation and a structurally different interface panel. A 95 kW system is therefore the last step where this panel makes sense: at 100 or 110 kW the distributor may still grant LV connection, but it is not automatic and the decision only arrives with the STMG. Before ordering the larger size, it is always best to have the connection solution in hand, not just the electrical design.
It should be remembered that at this power level the 20 kW threshold is already well exceeded, beyond which CEI 0-21 requires remote control and remote management by the distributor: the panel is prepared for external tripping of the SPI, which is the point where that command physically takes effect on the system.
The delicate point: the 140 A DDI
At 95 kW the output current is approximately 137 A per phase (95.000 W ÷ 400 V ÷ 1,732). The 140 A DDI contactor in AC3 category therefore operates practically at its rated current during peak production hours. This is not a sizing error - the AC3 category is already demanding and the operation of a DDI is rare, not cyclic - but it is a factor to take into account: the installation position and ventilation of the enclosure affect the contactor’s service life more than is often assumed. On a system actually operating at a constant 95 kW, a panel mounted facing south under sheet metal works in very different conditions from one in a ventilated technical room. At 75 kW the current drops to around 108 A and the margin becomes comfortable again.
What the panel contains
- SPI - interface protection compliant with CEI 0-21, supplied with test report
- DDI - 140 A-AC3 interface contactor, with in/out feed-through provision (DDI/M2)
- IMTD 4x160 A-10 kA - 300 mA class A residual current circuit breaker with overcurrent protection, with DDR backup
- IMT 4x160 A-10 kA - circuit breaker dedicated to inverter protection
- SPD - surge protection device
- 1P+N fuse holder for SPI power supply and 3P+N for measurement circuits
- Provision for external auxiliary power supply and external trip
- Input and output terminal blocks, single-line diagram, declaration of conformity Di.co
QAC 75/95 kW technical specifications
| System power | 75 - 95 kW, 1 inverter |
| Rated current | 160 A |
| Operating voltage | 400 V three-phase + neutral |
| Main protection | IMTD 4x160 A, 10 kA, 300 mA class A, with DDR backup |
| Inverter protection | IMT 4x160 A, 10 kA |
| Interface device (DDI) | 140 A-AC3 contactor |
| Interface protection (SPI) | Compliant with CEI 0-21, with test report |
| Surge protection device | SPD |
| Enclosure | 140 DIN modules, 640 x 750 x 240 mm, IP66 |
| Provisions | External auxiliary power supply, DDI/M2 in/out feed-through, external trip |
| Included documentation | Single-line diagram, Di.co, SPI test report |
| Manufacturer | Icierre - Italian construction |
Frequently asked questions
Is a 95 kW system connected in low or medium voltage?
Normally in low voltage: the operating threshold of ARERA TICA is 100 kW, below which the LV connection under CEI 0-21 is the standard solution. However, confirmation only comes from the minimum general technical solution (STMG) issued by the distributor, which assesses the capacity of the grid and the necessary works. This panel is sized for the LV scenario.
What is the SPI test report and why is it included?
It is the report of the functional tests performed on the interface protection with the voltage and frequency thresholds required by CEI 0-21, including the tests on the interface device. The distributor requires it as an attachment to the end-of-work documentation: without the test report, the connection procedure cannot be completed. Having it already included in the supply prevents the installer from having to organize on-site tests.
Is the panel suitable for two inverters in parallel?
This configuration is intended for a single inverter, because it contains only one IMT protection device on the inverter side. With two or more inverters, a version with as many dedicated protections as there are generators is required, or an upstream parallel panel. This is the point to clarify when ordering, because it cannot be solved by adding a module afterwards.
What is the DDR backup on the main circuit breaker for?
The backup is the reserve protection that trips if the main residual current device does not open. On a 160 A size, the fault current involved is high and selectivity must be guaranteed even in the event of failure to operate: the DDR backup is what prevents an uncleared fault from remaining powered by the grid.
Where should the panel be installed and how much space is needed?
The 140-module enclosure measures 640 x 750 x 240 mm and has an IP66 rating, so it is also suitable for outdoor use. However, front space for opening and a position sheltered from direct sunlight must be provided: 160 A devices dissipate heat and an enclosure exposed to the sun in summer operates close to the temperature limits allowed for modular components.