Core concepts.

For Worldwide: KKE Circuit is available across Global in English. Region: Global (INT).

What is a schematic drawing?

Quick answer: A schematic drawing is a multi-line representation of an electrical circuit that shows every conductor, every device, and every connection. Unlike a single-line diagram, which collapses three-phase circuits into a single line, a schematic shows phases L1/L2/L3 as separate conductors. Schematics are the working drawings that panel builders, electricians and technicians use to wire and troubleshoot a panel.

When to use a schematic instead of an SLD

• You need to show coil and contact details of a contactor, not just its presence.
• Panel builders need every wire labelled with colour, size, and number.
• Troubleshooting requires you to see how a control circuit reacts to inputs.

KKE Circuit specifics

• Schematics are drawn on the Schematic drawing type.
• Symbols come from the IEC 60617 library (or NEMA / UL alternates after switching standard).
• Reference designators auto-assign based on the project's standard: IEC uses K, Q, F, M, T, X; UL uses CR, CB, FU, MTR, XFMR, TB.

What is a single-line diagram (SLD)?

Quick answer: A single-line diagram (SLD) is a simplified one-line representation of a power distribution system. Three-phase power is shown as a single line; devices are shown as single-line glyphs. SLDs communicate the architecture of a power system — what feeds what, what is protected by what — without the wiring detail of a schematic. Used for power studies, switchgear documentation and incomer-to-load overviews.

SLDs are useful when

• You need a one-page summary of a panel for a customer or auditor.
• You are doing a load-flow or short-circuit study.
• You are documenting incomer + busbar + outgoing feeders.

KKE Circuit specifics

• Drawing type: Single-Line Diagram.
• Components placed on an SLD render as single-line glyphs, even if the same component appears as a multi-line symbol on a Schematic in the same project — this is the multi-variant symbols feature.
• Reference designators are shared across SLD and Schematic — K1 on the SLD is the same physical device as K1 on the Schematic.

What is a P&ID? (Process & Instrumentation Diagram)

Quick answer: A Process & Instrumentation Diagram (P&ID) is the master schematic of a process plant. It shows every piece of process equipment (pumps, vessels, heat exchangers), every pipeline (with size, material, fluid), every valve (manual and control), and every instrument (sensors, transmitters, controllers, valves). P&IDs are governed by ISA-5.1 (instrumentation symbols) and ISO 10628 (general P&ID rules). They are the single most important documentation artefact in process engineering.

Who uses a P&ID

• Process engineers — design and review of the plant.
• Operators — understand the plant during commissioning and operation.
• Safety engineers — HAZOP and SIL studies.
• Construction — piping bill of materials and fabrication.

KKE Circuit P&ID features

• Full ISA-5.1 instrument bubble library (FI, FT, PI, PT, LI, LT, TI, TT, LSH, LSL, PSH, etc.).
• ISO 10628 process equipment symbols (centrifugal pump, positive-displacement pump, gear pump, vessel types, heat exchanger types).
• Auto-coloured fluid lines — water blue, oil red, air cyan, hydraulic green — driven by the pin's fluid kind, not by manual colour selection.
• Seven ISA-5.1 line types out of the box.

What is a terminal strip drawing?

Quick answer: A terminal strip drawing documents every terminal block in a panel — terminal number, internal connection (which device pin), external connection (which field device pin), wire colour, cross-section, and cable ID. KKE Circuit auto-generates terminal strip drawings: every wire that crosses a panel boundary becomes a terminal row.

KKE Circuit's Panel Manager decides what is "inside the panel" and what is "field". The auto-generated terminal table is editable — you can override numbers, swap rows, or hide unused terminals.

What is a PLC I/O drawing?

Quick answer: A PLC I/O drawing shows the inputs and outputs wired to a programmable logic controller — one rack per sheet, one row per channel — with terminal numbers, signal type, field device, tag name, and address. KKE Circuit auto-generates the PLC I/O list from the connections drawn on the PLC drawing.

PLC drawings in KKE Circuit support digital input, digital output, analog input, analog output, RTD, thermocouple, and high-speed counter channel types.

What is a panel-to-panel interface drawing?

Quick answer: When a system is built from multiple panels (main panel, sub-panels, MCCs, remote I/O cabinets), the interface drawing documents every wire and every cable that runs between them. Cable type, conductor count, conductor cross-section, and source/destination terminal are all shown. KKE Circuit can derive this drawing from the netlist when components are assigned to panels.

What is an earthing/grounding drawing?

Quick answer: An earthing drawing documents the protective earth (PE) network of an installation: equipment grounding bonds, main earth bar, earth electrode, equipotential bonding, and the PE conductor sizing. KKE Circuit ships with earthing drawing types and PE-pin-aware connectivity — placing a PE pin on a device automatically connects to the project's PE network.

Wiring diagram vs. schematic — the difference

Quick answer: A schematic shows the function of a circuit using ladder or geometric layout — devices are placed where they make logical sense, regardless of physical position. A wiring diagram shows the physical reality — devices are placed where they actually live in the panel, and wires follow the actual cable route. The same components, two different views.

Aspect	Schematic	Wiring diagram
Layout	Logical (top-to-bottom power flow)	Physical (panel layout)
Wires	Idealised straight lines	Actual cable paths
Use	Design, troubleshooting	Build, install, retrofit
KKE Circuit type	Schematic	Wiring drawing

What is a netlist?

Quick answer: A netlist is the resolved list of every electrical net (every connected group of pins) in a project. KKE Circuit resolves the netlist across all sheets in a project automatically — cross-sheet net labels with the same name merge into one net, floating pins are flagged, and the resulting netlist powers the cable schedule, terminal strip generator, and PLC I/O list.

What is a Bill of Materials (BOM) in electrical engineering?

Quick answer: A BOM lists every component used in a project, with quantity, manufacturer, manufacturer P/N, your organisation's internal P/N, the drawing where it appears, and unit cost. In KKE Circuit, the BOM is generated automatically from the placed components across every drawing in a project, deduplicated, and exportable to CSV or pushed straight to Odoo as an mrp.bom.

What is a reference designator?

Quick answer: A reference designator is the unique label given to a component on a drawing — K1, Q2, M1, CR15, MTR3. The letter prefix encodes the kind of device (K = relay/contactor in IEC, CR = control relay in UL); the number distinguishes one instance from another. KKE Circuit auto-assigns the prefix based on the project's standard and increments the number as you place components.

What is a net label and how cross-sheet connectivity works

Quick answer: A net label is a piece of text attached to a wire that gives the net a name (L1, 24VDC, PE, MOTOR-1-RUN). When the same net label appears on two different sheets in the same project, KKE Circuit treats both wires as the same net. This is how a single power rail or a single I/O signal is shown on multiple sheets without drawing one impossibly long wire.

Conventions

• Use uppercase for power and ground nets (L1, N, PE, +24V, 0V).
• Use device-and-function for control nets (K1-COIL, M1-RUN, E-STOP-LOOP).
• Avoid spaces and special characters; underscore or hyphen.

What is a title block?

Quick answer: A title block is the boxed metadata panel in the bottom-right corner of a drawing that identifies the project, drawing number, revision, draftsperson, checker, approver, scale, sheet number, and date. In KKE Circuit, the title block is part of the page template and uses placeholder fields ({drawing_number}, {revision}, etc.) that resolve from project metadata at render time. Change a value in Project → Settings and every drawing's title block updates.

Schematic vs. SLD vs. P&ID — when to use each

You need to …	Use a …
Document the wiring of a panel for the panel builder	Schematic
Show the architecture of a power system at a glance	Single-Line Diagram
Document a process plant's pipes, equipment and instruments	P&ID
Trouble-shoot a control circuit	Schematic
Run a load-flow or short-circuit study	Single-Line Diagram
Run a HAZOP study	P&ID
Communicate scope to a process operator	P&ID
Document a pneumatic actuator system	Pneumatic Schematic (ISO 1219)
Document a hydraulic power pack	Hydraulic Schematic (ISO 1219)

Pneumatic vs. hydraulic schematics — what changes

Pneumatic and hydraulic schematics share the same standard (ISO 1219) and a large fraction of their symbol set — both use the same valve geometries, the same actuator notation, the same pump/compressor primitives. The differences are:

Aspect	Pneumatic	Hydraulic
Working fluid	Compressed air	Hydraulic oil
Pressure range	5–10 bar typical	100–300 bar typical
KKE Circuit fluid kind	air (auto-colour cyan)	oil (auto-colour red)
Common components	Compressor, FRL, 5/2 valve, cylinder	Pump, reservoir, relief valve, cylinder
Standard	ISO 1219-1 / -2	ISO 1219-1 / -2

What is a multi-variant symbol?

Quick answer: A multi-variant symbol is a single library entry that stores up to seven different geometric representations of the same physical component — schematic, single-line, three-phase, P&ID, control, panel front view, and terminal — and the canvas automatically picks the right one based on the drawing type. Add a Siemens 3RT2027 contactor once; it shows up correctly on every drawing without redrawing.

This is KKE Circuit's headline feature. It eliminates the duplicate-library problem that plagues every other electrical CAD tool — where you maintain a "schematic library" and a "panel-layout library" and have to keep them in sync by hand.

The seven variants

1. Schematic — multi-line geometry for use on schematics.
2. Single-line — collapsed glyph for SLDs.
3. Three-phase — explicit L1/L2/L3 representation for power drawings.
4. P&ID — ISA-5.1 / ISO 10628 process symbol.
5. Control — control-circuit-specific representation (often differs from main schematic for relays).
6. Panel front view — physical appearance for general arrangement drawings.
7. Terminal — minimal representation for terminal-strip drawings.

If a particular variant is not defined for a part, KKE Circuit falls back to the schematic variant.