Sub-Cycle Transfer Switches

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Ultra-fast sub-cycle transfer switch for critical power applications

The Innova STS (Sub-cycle Transfer Switch) is an advanced medium-voltage transfer system designed to protect sensitive loads from voltage sags, swells, and interruptions by seamlessly transferring the load between two independent power sources in less than one electrical cycle.

Built for critical power environments where even milliseconds matter, the Innova STS ensures continuity of operation, safeguarding equipment, processes, and productivity. With over 25 years of proven field experience, this is the ideal solution for industries where uptime is non-negotiable.

Key Benefits:

Sub-cycle transfer (<8 ms) to preserve uptime and avoid costly process interruptions
IEEE 446 compliant, aligned with CBEMA/ITIC curves for voltage tolerance
No energy storage needed, unlike UPS systems — reducing cost and maintenance
Air-cooled and transformerless, environmentally clean and low-impact
Minimal maintenance and fast ROI
Designed for industrial-scale MW-class loads with medium voltage operation
Backed by Southern States' 24/7 after-sales support and long-life engineering

Product Family

Innova STS

Medium-voltage sub-cycle transfer switch
Factory-assembled and tested for fast deployment
Designed for direct connection to dual feeds
Sub-cycle transfer time (<8 ms) ensures seamless power continuity
Ideal for sensitive, high-value loads with zero tolerance for interruptions
Compact footprint and air-cooled design simplify integration
Digital controller monitors voltage in real time and triggers automatic transfer
Minimal maintenance requirements and long operational life

Voltage Class	Basic Insulation Level (BIL)	Continuous Current	Fault Current Ride Through (X/R = 15)
Voltage Class	Basic Insulation Level (BIL)	(A)	Symmetrical (kA)	Asymmetrical (kA)
5 kV	60 kV	600	9, 18	23, 45
5 kV	60 kV	1,400	18	45
15 kV	95 kV	600	9, 18	23, 45
15 kV	95 kV	1,200	18	45
27 kV	125 or 150 kV	400	6, 9, 12, 18	15, 23, 30, 45
		600	6, 9, 12, 18	15, 23, 30, 45
		1,200	18	45
38 kV	150 or 200 kV	400	6, 12	15, 30
38 kV	150 or 200 kV	600	12	30

Product Bulletins

Innova STS Product Bulletin

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Data Sheets

Innova STS Data Sheet

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Applications and Industries

The Innova STS is designed for large commercial and industrial power consumers who have access to two or more independent medium voltage power feeds. The system detects sags, swells, momentary and sustained interruptions, and automatically transfers the load to the alternate power feed in milliseconds.

Ideal for sensitive load applications where even brief interruptions result in significant operational or financial impact, such as:

Semiconductor and Electronics

Prevents wafer loss and equipment damage from brief sags or interruptions
Maintains voltage stability in ultra-sensitive fabrication environments

Data Centers

Protects mission-critical servers from downtime
Complements existing backup power infrastructure

Hospitals and Research Labs

Ensures power continuity for life-support and sensitive instrumentation
Superior alternative to backup generator-based transfer systems

Airports

Maintains continuous power to critical systems like control towers, runway lighting, baggage handling, and security
Eliminates power-related delays, improving passenger experience and operational efficiency