Parameters
Inputs that describe variation, such as control load, incoming voltage, control voltage, motor horsepower, motor count, dimensions, or selected options.
Parametric electrical CAD built around inputs, logic, drawings, and outputs
Parametric electrical CAD is useful when the drawing is not a single fixed result. It is useful when inputs such as load, voltage, horsepower, dimensions, or options should resolve engineering decisions and generate coordinated variants.
What makes CAD parametric?
A parametric CAD workflow records enough of the design behavior to produce a valid result again when inputs change. For electrical work, that can mean load, voltage, horsepower, dimensions, or options resolving sizing and drawing decisions.
In LogiDraft, the parametric model is not only geometry. It includes parameters, variables, formulas, lookup tables, states, reusable definitions, nested assemblies, and structured outputs.
Concepts behind parametric electrical CAD
Variables
Computed values derived during evaluation. Variables can feed geometry, labels, state selection, nested blocks, and output fields.
Formulas
Expressions that calculate secondary values from parameters and variables so repeated engineering decisions are authored once.
Lookup tables
Table-driven selections for values such as transformer VA, fuse size, FLC, breaker, contactor, or overload range.
States
Conditional variants that can control which geometry, labels, or schematic details are active for the evaluated instance.
Outputs
Artifacts, BOM-style rows, schedules, or structured data that read from the evaluated result rather than a separate manual source.
A transformer sizing flow in parametric CAD
This is the core mental model: inputs resolve engineering values, then geometry and outputs consume those values.
1. Enter load and voltage
The placed control transformer instance receives load and voltage parameters from the project or parent assembly.
2. Resolve sizing logic
Formulas and lookup tables calculate transformer VA, protection values, and any state needed for the active variant.
3. Generate the drawing variant
The evaluated values drive labels, schematic visibility, repeated transformer groups, and related geometry.
4. Produce output data
Artifact fields can expose raw inputs and resolved values for BOMs, schedules, flat exports, or hierarchical JSON.
How LogiDraft applies the parametric model
LogiDraft lets teams author configurable systems rather than only drafting final geometry. Local Definitions and Global Blocks hold reusable behavior, while placed instances evaluate that behavior with specific inputs.
The evaluated instance is the key object: it is where parameters, variables, states, nested assemblies, drawing updates, and structured outputs come together.
Parametric workflows this helps explain
Control power sizing
Load and voltage can resolve transformer sizing, fuse selection, schematic variants, and output rows.
Motor starter selection
Horsepower and voltage can resolve FLC, protection, contactor, and overload values through formulas and lookup tables.
Reusable assemblies
Local Definitions and Global Blocks can capture behavior so repeated systems are varied through inputs instead of copied.
Physical layout generation
Dimensions and placement logic can generate layout geometry and expose structured output data from the same evaluated model.
Docs and examples for the parametric model
Logic documentation
Learn how formulas, lookups, parameter resolution, state selection, and injection resolve behavior.
Reuse documentation
See how reusable definitions and Global Blocks carry behavior across projects.
Control Transformer Sizing example
See load and voltage drive transformer and protection selection.
Mounting Plate Design example
See physical layout geometry generated from width, height, and hole logic.
Questions about this LogiDraft workflow
What is parametric electrical CAD?
Parametric electrical CAD uses inputs, formulas, lookup tables, reusable definitions, and evaluation rules to generate drawing and output variants instead of editing every result as fixed geometry.
How does LogiDraft use lookup tables?
Lookup tables can select engineering values from input conditions, such as transformer sizing from load and voltage or motor starter components from horsepower and voltage.
Are reusable blocks part of the parametric model?
Yes. In LogiDraft, blocks can contain parameters, variables, formulas, states, directives, nested references, and output-relevant fields, so reuse includes behavior as well as geometry.
Why does this matter for electrical drawings?
It matters because repeated electrical systems often change by input. Keeping parameters and evaluation rules in the design system helps drawings and outputs update from the same authored behavior.
Learn the parametric model before opening examples
Read the system model, then open a transformer or mounting plate example to see inputs, lookup tables, evaluated instances, drawing updates, and structured outputs in practice.