Ladder Builder

How to

Drag a part onto a rung, or tap a part and then tap a spot. Contacts and switches go on the left, one load (coil, motor, light) on the right. Drop a part in a dashed "branch" box under a rung to put it in parallel. Tap a placed part to see what it looks like, how to check it, and to press, set or remove it.

Log

Supply and examples

Control voltage Load example

Thermostat

76°ROOM

System

Fan

Room

Heat to

Cool to

Training aid only

Ladder Builder is a simplified simulator for learning to read and draw ladder (line) diagrams. It is not a design tool or a substitute for training, the equipment's wiring diagram, or the electrical code.

Each rung is checked as logic: closed contacts pass power, and a rung with no load is treated as a dead short.
Real arc flash and shock can kill. De-energize, lock out, tag out, and verify dead with a tested meter before you touch wiring.

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