FESS
Flywheel energy storage
A rotating mass coupled to a motor-generator and converter that stores energy kinetically for short, high-power bursts.
SLD
Symbols · RUPS
Rotary UPS
A UPS built around a rotating synchronous machine with kinetic storage, often coupled to a diesel engine for long backup.
In plain English
What does Rotary UPS mean?
A rotary UPS uses a synchronous machine running continuously on the critical bus, with stored kinetic energy in a flywheel or induction coupling bridging the gap until a coupled diesel engine starts and takes over. A choke between the utility and the critical bus lets the machine condition the supply and isolate the load from network faults.
A simple example
Single-line diagrams show the incoming utility feeder, a series choke, the synchronous machine with its kinetic energy module and clutch to the engine, and the critical and sometimes non-critical outputs. A bypass path around the unit is normally drawn.
What the drawings help you do
The machine provides real short-circuit current, unlike a static UPS, which helps downstream protection discriminate. The symbol does not show the ride-through time to engine pickup or the choke impedance, both of which matter for design.
This particular reference
A UPS built around a rotating synchronous machine with kinetic storage, often coupled to a diesel engine for long backup. A rotary UPS uses rotating machines and kinetic storage; a static UPS uses power electronics and a battery.
- Signal
- Electrical information passed between devices, rather than necessarily the main power supply.
- Rating
- A value stating the conditions for which equipment is specified.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: DC UPS, AC UPS and capacitor buffer modules · T-030 liquid-cooled generator set application manual
SLD · RUPS
What it represents
A rotary UPS uses a synchronous machine running continuously on the critical bus, with stored kinetic energy in a flywheel or induction coupling bridging the gap until a coupled diesel engine starts and takes over. A choke between the utility and the critical bus lets the machine condition the supply and isolate the load from network faults.
Single-line diagrams show the incoming utility feeder, a series choke, the synchronous machine with its kinetic energy module and clutch to the engine, and the critical and sometimes non-critical outputs. A bypass path around the unit is normally drawn.
The machine provides real short-circuit current, unlike a static UPS, which helps downstream protection discriminate. The symbol does not show the ride-through time to engine pickup or the choke impedance, both of which matter for design.
How to read it
- Identify the choke between the utility and critical bus.
- Check engine coupling and the kinetic module.
Information to show or reference
- State machine rating and ride-through time.
- Show choke, engine coupling and bypass.
- Reference fault current contribution.
A distinction that matters
A rotary UPS uses rotating machines and kinetic storage; a static UPS uses power electronics and a battery.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
DC UPS, AC UPS and capacitor buffer modules
Public UPS function context.
T-030 liquid-cooled generator set application manual
Public engine-generator application context.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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