# Transformer oil-surge trip interface Canonical URL: https://eloragrid.ai/symbols/transformer-oil-surge-trip-interface Publisher: Elora Grid Updated: 2026-11-03 Lookup label: TOTI Drawing use: Schematic Reference families: Manufacturer Representation: Functional block Installation focus: substations Input: Oil-surge relay contact Output: Assigned transformer trip initiation Transfers the applicable gas relay's oil-surge trip indication to the assigned protection logic. ## In plain English ### What this block does Transfers the applicable gas relay's oil-surge trip indication to the assigned protection logic. ### A simple example In a substation transformer bay, a protection panel receives winding-current measurements and equipment alarm contacts. An operator can then distinguish an electrical protection operation from a cooling-system or physical-condition alarm. For this reference, the drawing identifies “Oil-surge relay contact” at the input and “Assigned transformer trip initiation” at the output. Gas alarm and oil-surge trip are distinct outputs. ### What the drawings help you do Start at the named input: Oil-surge relay contact. Identify its source device or document and the state represented on the drawing. Follow the named output: Assigned transformer trip initiation. Cross-reference its destination and separate the command from confirmation that the equipment responded. ### Terms - Input: Oil-surge relay contact - Output: Assigned transformer trip initiation - Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections. Concept diagram: Oil-surge relay contact → TOTI → Assigned transformer trip initiation A reading guide. The entry's original illustration and input/output facts describe this application. - [SEL-487E transformer protection relay](https://selinc.com/products/487E/) ## What it represents Transfers the applicable gas relay's oil-surge trip indication to the assigned protection logic. Transformer monitoring interfaces connect physical sensors and protection calculations to the station's alarms and trip logic. Temperature, oil, gas, pressure and electrical measurements indicate different conditions and require separate interpretation. In a substation transformer bay, a protection panel receives winding-current measurements and equipment alarm contacts. An operator can then distinguish an electrical protection operation from a cooling-system or physical-condition alarm. For this reference, the drawing identifies “Oil-surge relay contact” at the input and “Assigned transformer trip initiation” at the output. Gas alarm and oil-surge trip are distinct outputs. Identify the sensor or calculation, its monitored zone and its assigned response. Alarm and trip thresholds, sensor fitting and protection settings belong to the selected transformer documentation and the approved protection design. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation. ## How to read it - Start at the named input: Oil-surge relay contact. Identify its source device or document and the state represented on the drawing. - Follow the named output: Assigned transformer trip initiation. Cross-reference its destination and separate the command from confirmation that the equipment responded. - Gas alarm and oil-surge trip are distinct outputs. - Identify the sensor or calculation, its monitored zone and its assigned response. Alarm and trip thresholds, sensor fitting and protection settings belong to the selected transformer documentation and the approved protection design. ## Information to show or reference - Label the source and connection reference for oil-surge relay contact. - Identify the destination and defined state of assigned transformer trip initiation. - Record the equipment or control-document revision supporting this functional block. - Check this application limit in the project design: Gas alarm and oil-surge trip are distinct outputs. ## Important distinction Gas alarm and oil-surge trip are distinct outputs. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram. ## Facts - Representation: Functional block - Installation focus: Substations - Input / boundary: Oil-surge relay contact - Output / connection: Assigned transformer trip initiation - Lookup label: TOTI is a library lookup label, not a standard device designation. ## Public references - [SEL-487E transformer protection relay](https://selinc.com/products/487E/) — SEL. Public technical context for transformer protection and monitoring interfaces. Transformer protection, monitoring and measurement interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation. ## Graphic scope Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.