Description
Automated whole-facility emergency power transfer.
GoodWe GW125K-STS-G10 is a 125 kVA commercial static transfer switch engineered to provide automated sub-10 ms grid isolation and whole-facility emergency power for GoodWe ET 40–100 kW and ETC 50–100 kW commercial hybrid inverters.
125 kVA High-Power Automatic Transfer
Seamlessly switches heavy commercial facilities between grid-connected and off-grid backup modes.
Essential Commercial Backup Companion
Mandatory accessory for GoodWe ET 40–100 kW and ETC series to unlock automated whole-facility emergency power.
Heavy-Duty Motorized Switchgear
High-speed motorized contactors provide rapid sub-cycle disconnection, preventing dangerous utility back-feeding.
Seamless Inverter Protocol Integration
Direct communication handshake with GoodWe commercial inverters for coordinated safety tripping and diagnostics.
More product details
Commercial facilities running automated machinery or refrigeration cannot tolerate prolonged power cuts. The GW125K-STS-G10 senses utility voltage loss instantaneously, opening motorized grid contactors and signaling the hybrid inverters to establish an off-grid microgrid.
- Motorized interlocked contactors achieve full physical galvanic isolation within <10 ms of grid drop.
- Eliminates micro-interruptions on critical industrial controllers, server racks, and automated packaging lines.
- Direct digital communication interface coordinates safety tripping with GoodWe commercial inverters.
Heavy-duty switchgear engineered for harsh electrical environments.
Handling up to 180.8 A per phase under continuous load, the switch features heavy internal busbars, motorized disconnect mechanisms, and an IP65 outdoor enclosure. Sized to carry full commercial main service currents up to 125 kVA continuously. Heavy-duty terminal blocks accommodate large copper conductors up to 95 mm². IP65 weatherproof casing installs cleanly indoors in switchrooms or outdoors beside pad-mounted transformers (-30 to +60 °C).
Takes 210 A across four power ports
Four connection terminals serve Grid, Back-up, Smart Port and Inverter. Rated capacity reaches 137.5 kVA.
Runs automated diesel generator control
The control interface starts a backup generator for prolonged outages. RS485 coordinates operation with the hybrid inverter.
Sits in an IP54 wall-mounted case
Operating temperature spans minus 35 to 60 C. The wall-mounted cabinet connects directly into commercial electrical rooms.
Technical data
The dedicated commercial transfer switchgear engineered for high-power ET and ETC hybrid inverters.
125 kVA commercial static transfer switch enabling automatic whole-facility backup.
Designed exclusively for GoodWe ET 40–100 kW and ETC 50–100 kW commercial hybrid inverters, the GW125K-STS-G10 enables automatic grid-tie to off-grid transitions. It handles up to 125 kVA continuous apparent power (180.8 A per phase), providing rapid sub-cycle isolation to protect commercial cold storage, automated production lines, and data centers against utility power disruptions.
- Heavy Commercial Rating
- 125 kVA
- Sub-Cycle Transfer
- < 10 ms
- Utility Back-Feeding
- Zero
- Outdoor Enclosure
- IP65
Electrical Ratings
- Nominal voltage (V)
- 127/220, 220/380, 230/400, 240/415, 3L/N/PE
- Voltage range (V)
- 114 ~ 280 (per local standard)
- Nominal frequency (Hz)
- 50 / 60
- Frequency range (Hz)
- 45 ~ 55 / 55 ~ 65
- Rated current (A)
- 210
- Max. current (A)
- 210
- Rated power (kW)
- 125.0 (75 @ 220 V)
- Max. apparent power (kVA)
- 137.5 (75 @ 220 V)
Switching & Control
- On-grid / off-grid transfer time
- < 10 ms
- Generator control
- Yes, diesel generator control supported
- Communication
- RS485
- Ports
- Grid / Back-up / Smart Port / Inverter side
Mechanical
- Ingress protection
- IP54
- Mounting
- Wall-mounted
- Operating temperature (°C)
- -35 ~ +60
Project fit
Where this model fits.
Scenarios that show which projects the GoodWe GW125K-STS-G10 belongs in, what to verify before quoting, and when another model is the better pick.
Mandatory Backup Switchgear for GoodWe ET (40–100 kW) and ETC Inverters
Commercial installations deploying GoodWe ET 40K, ET 50K, ET 80K, ET 100K, or ETC series inverters where automated whole-facility backup power is required.
Commercial inverters in this power class do not contain internal AC bypass contactors; the GW125K-STS-G10 is the factory-certified external switch required to enable backup operation.
- Confirm this model against the adjacent rating in the same family
Documents
GoodWe STS 125 kW (GW125K-STS-G10) datasheet, EMEA (EN)Product questions
Why do GoodWe ET 40–100 kW inverters require this external STS box for backup power?
High-amperage commercial currents require dedicated external motorized contactors. Unlike smaller residential inverters (5–10 kW) that house small internal 22.7 A bypass relays, commercial inverters handling 40 kW to 100 kW+ operate with currents exceeding 60 A to 160 A+. Housing large motorized industrial contactors inside the inverter chassis would drastically increase inverter size and heat. The external GW125K-STS-G10 provides heavy-duty, utility-grade isolation in a separate dedicated enclosure.
What is the maximum cable size supported by the STS box terminals?
Supports copper conductors up to 95 mm² / 120 mm². The internal heavy-duty terminal blocks are sized to accept large commercial copper cables up to 95 mm² (or 120 mm² with compression lugs) to handle continuous 180.8 A currents with minimal resistive voltage drop.