Sunways 5–20kW Three-Phase Hybrid Inverters Added to BIS Registration in India
The Bureau of Indian Standards (BIS) has approved the inclusion of seven Sunways STH-5–20KTL-LT three-phase low-voltage hybrid inverter models in the company’s existing BIS registration. The addition took effect on 28 September 2026 under registration R-41201685, providing a documented certification update for Sunways partners, distributors and installers in India.
The approval is recorded in BIS inclusion letter 109110 and covers STH-5KTL-LT, STH-6KTL-LT, STH-8KTL-LT, STH-10KTL-LT, STH-12KTL-LT, STH-15KTL-LT and STH-20KTL-LT. Together, these models represent the series’ 5 to 20kW power range. The letter identifies the manufacturing unit as Ningbo Sunways Technologies Co., Ltd.
For partners evaluating Sunways equipment for Indian solar-plus-storage projects, the update brings the listed STH-LT models within the documented scope of the company’s BIS registration. The model list, effective date and registration reference provide a common basis for documentation requests and product discussions, alongside the relevant specifications.
BIS Registration Extended to Seven STH-LT Models
The inclusion letter lists IS 16169:2019, IS 16221 (Part 2):2015 and IS 17980:2022, together with their corresponding IEC references. It confirms that the additional models have been included within the scope of the existing licence, with its other terms and conditions unchanged.
The document therefore records an extension of the registered model scope. This distinction matters when partners assemble product documentation: the series name identifies the product family, while the seven individual model names establish which products are covered by this particular inclusion.
The approval covers every model listed in the announcement, from the STH-5KTL-LT through to the STH-20KTL-LT. Partners working with different power ratings can refer to the same inclusion letter while matching their selected model to its corresponding datasheet entry.
By stating the registration number and inclusion date directly, the announcement provides a traceable reference for product discussions. These details also help distinguish the current certification update from earlier product introductions or registrations concerning other Sunways inverter families.
A Documented Update for Indian Partners and Installers
For Indian distributors, installation partners and project teams, the addition provides model-specific registration information for the STH-LT range. The letter can form part of the documentation reviewed during product evaluation, customer discussions and preparation of project submissions.
The practical value of this update lies in connecting the certification record to identifiable products. A distributor discussing a particular inverter, an installer reviewing a proposed configuration and a project team requesting supporting documents can each refer to the exact model and the same BIS inclusion reference.
The update concerns the inverter models listed in the letter. Product configuration, battery compatibility and project requirements remain separate topics for technical discussion. Sunways partners can use the registration information together with the datasheet to build a clearer picture of the equipment being considered for an individual installation.
This makes the announcement relevant to both commercial and technical conversations. It supplies the certification reference for the named models while directing readers to the product information needed to continue their evaluation.
STH-LT Features for Solar-Plus-Storage Applications
The Sunways STH-5–20KTL-LT series combines three-phase operation with low-voltage battery storage across a 5 to 20kW range. Its product platform is relevant to residential backup and small commercial solar-plus-storage applications, where project teams are considering solar generation, stored energy and backup loads within one installation.
Alongside the BIS registration update, the official product datasheet provides the technical context for the series. Four features are particularly relevant to partners reviewing the platform:
- Four MPPTs on the 12, 15 and 20kW models. These versions provide four separate maximum power point tracking channels for PV strings, giving project teams additional array configuration options within the specified input limits.
- Dual battery inputs on the 12, 15 and 20kW models. The two battery input connections are a model-specific feature that partners can discuss when reviewing the proposed storage configuration.
- UPS switching time below 10ms. The datasheet specifies a rapid transition to backup operation, making switching performance a relevant part of discussions about designated backup loads.
- IP66 protection. The series’ specified protection rating forms part of its product documentation and installation planning information.
These features should be read against the selected model rather than treated as identical across the entire range. The 5 and 6kW versions have two MPPTs, while the 8 and 10kW versions have three. Models from 5 to 10kW have one battery input.
These differences reflect the configurations documented for individual products within the STH-LT family. With the BIS inclusion covering all seven listed models, partners can discuss the registered range while maintaining a clear distinction between the available PV and battery connections.
Residential Backup and Small Commercial Project Context
The registration update is relevant to partners evaluating the STH-LT series for three-phase residential and small commercial projects in India. In these applications, the product discussion can cover both solar-plus-storage operation and the requirements of designated backup loads.
The range offers several power ratings within the same product family, allowing conversations to focus on the model being proposed for a particular installation. Higher-power versions provide four MPPTs and two battery inputs, while smaller models have their own documented configurations.
For residential projects, readers can explore Sunways residential solar solutions for broader application context. For enquiries about the registered STH-LT models, Sunways invites partners to share their project requirements and request the relevant documents.
Documentation and Next Steps for Indian Partners
Partners can review the STH-LT English datasheet for individual model specifications. Further background on system selection is available in the three-phase hybrid inverter guide.
The BIS inclusion letter and the product datasheet serve complementary purposes: the letter identifies the registration scope, while the datasheet describes the equipment’s technical specifications. Together, they support a more informed conversation about the STH-LT model under consideration.
Indian distributors and installers evaluating the series can contact Sunways with their intended model and project requirements to request the BIS inclusion documentation and discuss product selection.
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