TGAI
Transformer gas-accumulation alarm input
Receives the defined gas-accumulation alarm from an applicable liquid-filled transformer gas relay.
Functional block
Electrical symbols.
Explore electrical symbols, functional blocks and circuit arrangements for switchgear, switchrooms, substations, switchyards and microgrids. Detailed explanations, drawing notes, public sources and original SVG/DXF illustrations.
Substations
TOTI
Transformer oil-surge trip interface
Transfers the applicable gas relay's oil-surge trip indication to the assigned protection logic.
Functional block
TSTI
Transformer sudden-pressure trip interface
Receives the defined sudden-pressure protection contact for the assigned transformer tank.
Functional block
TPOI
Transformer pressure-relief operated indication
Reports operation of the installed pressure-relief device independently of electrical fault detection.
Functional block
TMOA
Transformer main-tank oil-level alarm
Reports the documented low or abnormal oil-level condition in the main tank system.
Functional block
TTOA
Transformer tap-changer oil-level alarm
Separates the tap-changer oil-system level indication from the transformer main-tank indication.
Functional block
TTTAI
Transformer top-oil temperature alarm interface
Receives the measured top-oil temperature condition used for the defined alarm action.
Functional block
TWTTI
Transformer winding thermal trip interface
Carries the selected winding thermal protection result to the assigned trip logic.
Functional block
TCCA
Transformer cooler common-failure alarm
Collects the assigned transformer-cooling equipment failures into a clearly named bay alarm.
Functional block
TCSI
Transformer cooler supply-loss input
Reports loss of the monitored electrical supply to the transformer cooling system.
Functional block
TTAM
Transformer through-fault accumulation monitor
Records the defined exposure of the transformer to external fault-current events.
Functional block
TNMI
Transformer neutral-current measurement interface
Identifies the separately measured transformer neutral-current signal serving the assigned protection input.
Functional block
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Read the drawing, not just the mark
Small details. Different meanings.
Understand symbols, equipment tags and function numbers—and know when a generic object needs a manufacturer drawing.
In plain English
What do electrical symbols tell you?
Electrical symbols are shorthand for equipment, functions and connections. They let you follow how a circuit works without drawing every physical detail.
A simple example
On a microgrid single-line diagram, a current-transformer symbol marks a measurement point and a breaker symbol marks where a circuit can be disconnected. Their labels identify the actual equipment.
What the drawings help you do
Follow the connected lines to trace power or control signals. Use the project legend to interpret symbols and the selected manufacturer's drawings for dimensions and terminal connections.
- Single-line diagram
- A simplified power-system drawing that often uses one line to represent a three-phase circuit.
- Legend
- The key explaining a drawing's symbols and labels.