Deye SUN-STS500 module

This product is not a battery, although it appears in the same family of equipment. It is an automatic switch: a device that decides, instead of a human, from where the building is supplied — from the public grid, from the battery system or from the diesel generator. When the grid goes down, it moves the supply so quickly that most equipment does not notice, and when the grid returns, it switches back. Without it, the transfer between these sources would have to be done manually or would not be possible at all.

The module has three independent three-phase ports, each sized at 500 kW: one towards the grid and the converters, one towards the loads and one towards the generator. The switching time in off-grid mode is under 20 ms, enough for sensitive loads, such as computers or automation systems, not to reset. A single module covers up to 500 kW of conversion power, that is for example five 100 kW PCS modules or four 125 kW ones. The box measures 543 x 575 x 671 mm and 108 kg, natural cooling without fans — so no noise and no parts that wear out — but with an IP20 protection degree, which means mandatory installation in a protected technical room, alongside the other modules.

Working voltage 220/380 V or 230/400 V, 3L/N/PE configuration, 50 or 60 Hz, rated current 758 A on the input and 725 A on the output. Overvoltage category OVC III, compliance declared to IEC/EN 61439-1 and 61439-2 for low-voltage switchgear assemblies. It is used exclusively together with the rest of the Deye C&I ESS components: BOS-B racks, PCS modules and MPPT modules.

Who it suits

Suitable for Deye industrial storage installations exceeding 100 kW which must automatically transfer to the batteries or to the generator when the grid fails; it is bought as part of the system, not separately.

Terms explained

• STS (static transfer switch): A switch with no mechanical parts that changes the supply source in milliseconds, much faster than an ordinary contactor.
• Island operation (off-grid): The situation in which the building supplies itself, from batteries and panels, disconnected from the public grid.
• OVC III: The class of resistance to the voltage peaks occurring in the fixed installations of buildings, for example on switching or distant lightning strikes.

Technical specifications

Recommended applications

• Automatic grid / storage / generator transfer in Deye industrial storage systems
• Ensuring island operation for critical load boards
• Integration of the diesel generator into a hybrid photovoltaic system with batteries
• Extending a C&I ESS installation above 100 kW with several PCS modules in parallel

Technical details

Series-level specifications — valid for the product family

Note the classification: SUN-STS500 is not a battery, but the static transfer switch module of the Deye C&I ESS solution. Its role is to automatically transfer the supply of the loads between the public grid, the storage system in off-grid mode and the diesel generator, without manual intervention.

The module has three independent three-phase ports, each sized at 500 kW: the grid/PCS port, the load port and the generator port. The working voltage is 220/380 V or 230/400 V, in a 3L/N/PE configuration, at 50 or 60 Hz. The rated currents are 758 A on the input and 725 A on the output. The switching time in off-grid mode is under 20 ms, enough for most sensitive loads not to feel the interruption.

In construction it is a module with natural cooling, without fans, with dimensions of 543 x 575 x 671 mm and 108 kg. The protection degree is IP20, so it is mounted in a protected technical room, in the same assembly with the PCS modules. The overvoltage category is OVC III, and compliance is declared to the IEC/EN 61439-1 and 61439-2 standards for low-voltage switchgear assemblies.

A single module covers up to 500 kW of conversion power, that is for example five 100 kW PCS modules or four 125 kW PCS modules. It is used exclusively together with the rest of the Deye C&I ESS components (BOS-B racks, PCS modules, MPPT modules).