Deye SUN-STS500L 500kW transfer switch moduleSwitching between grid, generator and loads for Deye PCS storage systems

Overview

The SUN-STS500L decides where the energy comes from: grid, generator or battery. It handles 500kW on all three sides, switches in 10ms or less and houses the 250A breaker for the PCS AC cable, the metering circuits for grid, loads and generator, the generator start contacts and two digital inputs. One module serves one 500kW PCS or four 125kW PCS, and up to five modules run in parallel for 2.5MW. It is supplied with the industrial storage kits that include it rather than as a single part; as a spare or for extending an existing plant it is quoted on request.

• 100 or 125kW bidirectional, three-phase 230/400V
• 630–1000V lithium battery, up to 200A
• 98.5% maximum, 97.8% European efficiency
• Integrated EMS: zero export, TOU, peak shaving
• Scalable to 2.5MW with STS modules
• IP65 module, -40…+60°C, up to 4000m

How it works

The PCS module is the AC/DC converter of Deye's 100kW–2.5MW commercial and industrial storage system. It charges and discharges a 630–1000V lithium battery, at up to 175A on the 100kW model and 200A on the 125kW model, and exchanges power with a three-phase 220/380V or 230/400V grid with a power factor adjustable from -1 to 1. PV arrays are added on the DC side through Deye MPPT modules, and an STS module handles switching between grid, off-grid and generator operation.

Key features

An energy management system is built into the PCS and covers zero export, time-of-use optimisation, peak shaving and demand management, with local touchscreen control and remote monitoring through Deye Cloud. With the STS module, switching between on-grid and off-grid takes under 10ms according to the 2026 brochure, and the brochure advertises a “2×” off-grid overload for 12 seconds. Confirm the reference power and continuous off-grid load limit in the installation documents before sizing the loads. Each MPPT module offers 8 trackers at up to 40A and up to 200kWp of PV.

Installation and compatibility

One STS module of 500kW serves up to four 125kW or five 100kW PCS modules, and five STS modules form a 2.5MW system. Each PCS supports up to 16 BOS-B battery clusters; Deye's BOS-B-AP-A cable package is designed for the 125kW PCS, and the BOS-B-PDU-2-A high-voltage box links clusters to the PCS. The PCS01HP3 version must be paired with the SUN-MPPT-L01-EU-AM8 module and its battery cables are made on site, whereas the PCS02HP3 version uses pre-fabricated cables.

The datasheet lists IEC 61727, IEC 62116, CEI 0-21, EN 50549, NRS 097, RD 140, UNE 217002, OVE-Richtlinie R25, G99 and VDE-AR-N 4105, with IEC/EN 62477-1 for safety. The PCS module is IP65, the STS cabinet IP20. A breaker certified to IEC 60947-1 and IEC 60947-2 must be installed on the AC side, and all work must be done by qualified personnel.

Monitoring and settings

The PCS has an LCD, function buttons and Wi-Fi, RS485, CAN and meter interfaces, plus BMS, MPPT CAN, parallel and logger ports. Operating range is -40 to 60°C with derating above 45°C, humidity 0–95% and altitude up to 4000m, with intelligent air cooling and noise below 75dB. The warranty is 5 years, extendable to 10 years depending on the installation site.

Questions and answers