# Control-circuit continuity test boundary Canonical URL: https://eloragrid.ai/symbols/control-circuit-continuity-test-boundary Publisher: Elora Grid Updated: 2026-11-03 Lookup label: CCTB Drawing use: Schematic Reference families: Manufacturer Representation: Functional block Installation focus: switchgear Input: Test boundary terminals Output: Observed path continuity Identifies the defined terminals included in a control-path continuity check. ## In plain English ### What this block does Identifies the defined terminals included in a control-path continuity check. ### A simple example In a switchgear relay panel, test links can separate a protective relay from the trip coils while maintaining the specified current-transformer secondary arrangement. For this reference, the drawing identifies “Test boundary terminals” at the input and “Observed path continuity” at the output. Continuity does not demonstrate loaded operating performance. ### What the drawings help you do Start at the named input: Test boundary terminals. Identify its source device or document and the state represented on the drawing. Follow the named output: Observed path continuity. Cross-reference its destination and separate the command from confirmation that the equipment responded. ### Terms - Input: Test boundary terminals - Output: Observed path continuity - Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections. Concept diagram: Test boundary terminals → CCTB → Observed path continuity A reading guide. The entry's original illustration and input/output facts describe this application. - [Masterclad medium-voltage switchgear: circuit-breaker section interlocks](https://productinfo.se.com/masterclad_mv_switchgear_ib/6055-30-masterclad-15kv-mv-switchgear-ib/English/6055-30%20Masterclad%20MV%20Switchgear%20Indoor%20%28bookmap%29_DD00646805.xml/%24/Section6-CircuitBreakerSectionInter-58DD6EC7) ## What it represents Identifies the defined terminals included in a control-path continuity check. A test interface separates measurement, command and indication paths so their behavior can be checked in the documented test configuration. The test boundary must show which real equipment outputs remain enabled. In a switchgear relay panel, test links can separate a protective relay from the trip coils while maintaining the specified current-transformer secondary arrangement. For this reference, the drawing identifies “Test boundary terminals” at the input and “Observed path continuity” at the output. Continuity does not demonstrate loaded operating performance. Trace the source and destination on each side of the test boundary. Use the selected test-device instructions for actual operations and never infer a safe current-transformer switching sequence from an educational diagram. 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: Test boundary terminals. Identify its source device or document and the state represented on the drawing. - Follow the named output: Observed path continuity. Cross-reference its destination and separate the command from confirmation that the equipment responded. - Continuity does not demonstrate loaded operating performance. - Trace the source and destination on each side of the test boundary. Use the selected test-device instructions for actual operations and never infer a safe current-transformer switching sequence from an educational diagram. ## Information to show or reference - Label the source and connection reference for test boundary terminals. - Identify the destination and defined state of observed path continuity. - Record the equipment or control-document revision supporting this functional block. - Check this application limit in the project design: Continuity does not demonstrate loaded operating performance. ## Important distinction Continuity does not demonstrate loaded operating performance. 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: Switchgear - Input / boundary: Test boundary terminals - Output / connection: Observed path continuity - Lookup label: CCTB is a library lookup label, not a standard device designation. ## Public references - [Masterclad medium-voltage switchgear: circuit-breaker section interlocks](https://productinfo.se.com/masterclad_mv_switchgear_ib/6055-30-masterclad-15kv-mv-switchgear-ib/English/6055-30%20Masterclad%20MV%20Switchgear%20Indoor%20%28bookmap%29_DD00646805.xml/%24/Section6-CircuitBreakerSectionInter-58DD6EC7) — Schneider Electric. Public technical context for switchgear test and commissioning interfaces. Breaker control, mechanism, position contacts, racking interlocks and test 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.