The system can manage any type of generator set as long as it produces voltage of 230 V +/- 10% and frequency of 50.0 Hz. The connection is made at a frequency of between 49.0 Hz and 51.0 Hz, while disconnection occurs below 47.5 Hz and above 51.5 Hz.

For off-grid mode the MPPT controller accepts a voltage range between 90 and 160 V (120 V is recommended for optimal efficiency of the MPPT). The maximum power output for each MPPT does not exceed 3.3 kW. For on-grid mode on the other hand, the MPPT controller accepts a voltage range of 200 to 600 V, with a recommended range from 300 to 400 V .

ZHERO is designed for use in single-phase residential installations. However, ZHERO can be installed in a three-phase line on one of the 3 phases on the condition that it supplies only single-phase services. This is due to the fact that in the event of an interruption of the line passing through ZHERO, the other phases of the system would not be interrupted, causing possible damage to the connected devices.

No. The system is automatically bypassed under fault conditions. If this also does not occur, the user can manually turn the main circuit breaker to position 2, which allows manual bypass of the system, restoring the power supply until the installer's intervention.

Yes, it is possible to use ZHERO as a back-up unit, rechargeable from either a solar power system, the mains network, or a generator set. It is not certified as a UPS.

There are several factors that influence sizing of a solar power system with storage, such as the place of installation, exposure to the sun, maximum installable power, type of use of the system, etc.

The ZHERO ambient temperature range is -10 to +40 °C.

Simply remove the protective skirt covering the feet and use a normal pallet truck. If necessary, the unit can be broken down into 3 parts: battery body, main body and cap. Also the side panels can be removed from the central body.

Maintenance must be carried out by authorised personnel. The device requires only careful cleaning of the air filters on the front pockets and upper fan, to ensure the air flow is not obstructed by accumulated dust. It is also advisable to ask the maintenance technician to check the various AC and DC terminals in the unit to ensure they are properly tightened.

ZHERO should ideally be installed in a well-ventilated service room, although there are no binding prescriptions in this respect. In any case, rooms subject to very high temperatures should be avoided and ZHERO must not be exposed to direct sunlight. Avoid also installation sites subject to the risk of flooding. Check also that the floor is designed to withstand a load of 300 kg/m2.

ZHERO's protection rating is IP20.

Yes, but there is no electric car communication protocol implemented at present. It is anyway possible to connect the 220 V power supply to ZHERO in the same way as with a normal electrical outlet.

As a guideline, the energy consumed by a user with an on-site exchange contract is between 20 and 30%. With ZHERO, comparing different systems installed in the field, the figure is between 65 and 75%, with peaks of up to 90%. The apparent randomness of the values can be mitigated by smart energy usage strategies.

Yes. The unit is configured for this function. The priority load is programmable according to the user's needs. Priority loads are currently selected by closing a voltage-free contact.

Yes. The CPU board is already configured for connection via a voltage free contact that can be remotized from ZHERO.

Absolutely not. All work must be approved by UNE and carried out only by authorised personnel.

No, the entire system is grounded and completely safe. In the event of an insulation fault, the system will automatically assume safety status.

Yes, the eyebolts on ZHERO's cap can be used for this purpose. In addition, the system feet have holes for fixing to the floor to provide additional stability.

Yes, ZHERO is equipped with specifically designed surge arresters (OPT). In addition, there are numerous fuses that limit the potential for the propagation of lightning discharges.

Yes, but UNE's prescriptions concerning the enclosure and connection methods given in the installation manual must be followed.

This value depends greatly on the type of consumer. Consumption of the home can be assessed along with the necessary investment.

It depends. The solar power system can be maintained, checking however that the strings have maximum voltage between 80 - 180 V and current not exceeding 10 - 12 A each. In addition, the original inverter becomes completely obsolete as everything is and must be managed by ZHERO.

In the case of an existing home, there is a 50% deduction on the total amount spent, reimbursed over a period of 10 years. If combined with a heat pump or heating system, the deduction is 65%.

With correct plant sizing and careful use of the energy produced, long periods of complete independence from the grid are possible. Total energy independence requires an external generator set to compensate for periods of low solar power generation.

No. ZHERO is designed to work with its own salt batteries.

If the generator set is an older legacy system or of low quality, able to generate only irregular frequency or frequency outside the acceptable range, connection becomes difficult. In such cases, it is preferable to replace your original generator set with a new state-of-the-art model.

No, the eyebolts are provided to secure the unit to the wall.

Yes, the storage capacity can be upgraded by requesting the provision for second battery immediately, or the complete upgrade can be carried out at a later date.

Yes, the system is designed also to provide this function, even without a generator set.

ZHERO is shipped on a pallet, fully assembled and ready for commissioning. For special installation cases, the system can be shipped in disassembled condition.

Yes, as with a normal connection of a solar power system to the electricity grid, an external generation meter is required. In case of an off-grid situation, this will not be necessary.

Yes, a residual current device must be installed at the start of the line, ideally using a class A, 300 mA selective device.

Although there is sufficient space, it is preferable to keep the circuit breakers outside the unit near the generation meter.

Currently 1, but UNE can provide customised solutions on request.

The DC and AC terminal blocks are accessible via knock-out holes on the box. In fact, 4 knock-outs have been created to be removed according to wiring needs, to be fitted with cable glands (PG36) or conduit box fittings.

It is certainly necessary to upgrade from a 3 kW to a 6 kW meter to take full advantage of ZHERO's potential. Using more power than your installed meter power is inadvisable for reasons of electrical safety and regulatory constraints.

Yes. Input power and withdrawal power need not necessarily to be identical. It is permissible to have input power of 6 kW due to the presence of the ZHERO and (contractual) withdrawal power of 3 kW. However, the 6 kW of input power can only be used if the system has sufficient energy in the battery and, hypothetically, only in months with high levels of sunlight. In winter, for example, the system will be frequently connected to the public grid due to absent or low levels of sunlight, so the withdrawal power value frequently approaches 3 kW, disruptions may occur due to tripping of the electricity company's meter circuit breaker. Users who are attentive to this aspect can do this, but those who are less informed of such conditions may interpret such interruptions as system faults.

There is no obligation to switch to a three-phase supply. In terms of the relationship with the grid, the important parameter is the inverter output power.