Every common E&I symbol in one filterable index: receptacles, switches, lighting, power gear, raceways, one-line and instrument symbols, each with how an estimator counts it in a takeoff.
An E&I (electrical and instrumentation) bid package mixes drawings that answer different questions. Knowing which sheet a symbol sits on tells you whether you are counting it, measuring it or pricing it as major equipment.
Floor, power, lighting and site plans are drawn to scale, so they give both device counts and the lengths of conduit, cable tray and wire.
A one-line shows how power flows from the utility to each load. It lists the major gear and its ratings but carries no lengths, so feeder footage comes from the plans.
P&IDs (piping and instrumentation diagrams), loop drawings and the instrument index give every tagged device. Each tag is one device to mount, wire, terminate and loop check.
Bring an electrical or instrumentation package you are bidding now. In the demo, The Takeoff AI reads the plans, one-lines and instrument drawings, counts every symbol in this library, measures the conduit and cable tray, and prices the bill of materials (BOM), with every number linked back to the symbol on the sheet.
Book a Takeoff Demo →Upload the E&I set as PDF, the way it came with the bid.
Devices, fixtures, panels, raceways, one-line gear and instrument tags are found and sorted by type.
Each symbol is counted by type and mounting, and conduit, cable tray and wire are measured by size.
Click any line in the takeoff to see the symbol it came from, then take the priced BOM into your bid.
Each symbol stands for a device, a piece of equipment or a wiring method. Circles with lines are receptacles, an S is a switch, rectangles are usually light fixtures or panels, and lines show conduit and circuits. Instrument bubbles carry a tag that names what the device measures and does.
One-line and schematic symbols follow IEEE 315, also published as ANSI Y32.2. IEEE now lists the 1975 edition as inactive-reserved, but most US one-lines still draw from it, with protective device numbers from IEEE C37.2. Instrument symbols follow ANSI/ISA-5.1 and fire alarm symbols follow NFPA 170. Plan symbols vary by engineering firm, which is why every set has its own legend sheet.
It is a duplex receptacle, the standard two-outlet wall plug. One line means a single receptacle, and extra letters beside it, such as GFI or WP, mark ground-fault protection or a weatherproof cover.
A one-line diagram shows the power system as a single line from the source to each load, with breakers, transformers and switchgear in order. A plan shows where everything physically sits in the building or plant. Estimators take equipment from the one-line and counts and lengths from the plans.
They read the legend first, then count devices by type on each plan, measure conduit and tray runs, and take major gear from the one-line and the schedules. Counts are kept by type, size and mounting, because a GFCI or a weatherproof device prices differently from a standard one.
Under ANSI/ISA-5.1, the first letter is what the instrument measures, such as P for pressure or F for flow, and the next letters are what it does, such as T for transmit or SH for switch high. PT-101 is a pressure transmitter on loop 101, and the line through the bubble shows where it is mounted.