Electrical Abbreviations List: 228 Terms in a Free DWG Legend

What is in this legend

This electrical abbreviations legend gives you 228 terms in one table, ready to paste onto a drawing sheet. The terms are split into fourteen groups: supply and substations, distribution, standby and emergency power, switching and protection, motor control, poles and phases, cables and containment, earthing and lightning protection, lighting, wiring devices, fire alarm and ELV, design parameters, units, and drawings and general terms.

The table is drawn at paper size in millimetres, 510 mm wide and about 330 mm tall, in four columns. It fits beside the title block on an A1 sheet at a scale of 1 in paper space. All text is plain single line text on its own layers, so you can change a description, delete a row or add your own terms without exploding anything.

Terms used on Saudi and Gulf projects

The list follows the way drawings are actually labelled on projects in Saudi Arabia and the Gulf, where British and IEC terms sit alongside American ones. The distribution hierarchy is written as MDB, SMDB and DB, with EMDB and EDB for the emergency side, which is how most consultants in the region name their boards. Feeder pillars, ring main units and package substations are included because they appear on every site plan that connects to a Saudi Electricity Company supply.

Phases are listed as L1, L2 and L3. Older drawings and some site teams still use R, Y and B, and you will see both on the same project when an old building is extended. Pick one for the drawing set and stick to it, especially on single line diagrams and panel schedules, where a mixed convention makes phase balancing harder to check.

Electrical abbreviations that clash

A handful of electrical abbreviations have two common meanings, and a legend cannot show both. In this table each one has a single meaning. CT is the current transformer, so cable tray is written CTR. FP is the feeder pillar, and the four pole breaker is 4P. MH is the manhole, so mounting height is written MTG HT. ES is the exit sign, and the emergency stop is E-STOP. CL is the cable ladder, so the legend does not use CL for a centre line.

Clashes also happen between disciplines. FCU is a fan coil unit to every HVAC engineer, so the fused spur is listed here as FSU rather than as a fused connection unit. SD is a smoke detector in this list and a smoke damper in most HVAC legends. On a coordinated MEP drawing both can appear on the same ceiling plan, so agree with the HVAC side which one changes before the composite drawings go out.

Using electrical abbreviations on a drawing set

Put the full legend on the first sheet of the electrical set or on a separate legends sheet, and refer to it from the rest. Repeating it on every drawing takes space and means every copy has to be revised when one term changes.

Trim the list before issue. A villa does not need RMU, MVSG and PSS on its legend, and a fit-out package rarely needs the substation terms at all. Keep the full version in your template and cut it down for each job, so the legend only shows terms that are actually on the drawings.

Use the same names everywhere. The board called SMDB-2 on the single line diagram should be SMDB-2 on the layout, on the panel schedule, in the cable schedule and on the label fixed to the board on site. Most of the confusion during testing and commissioning comes from a board or circuit that carries a different name on each document, and it starts with an abbreviation that was not fixed at the beginning.

File details

• Format: DWG
• 228 abbreviations in 14 groups
• Drawn at 1:1 paper size, 510 x 330 mm, four columns
• Layers: AB-GRID, AB-BORDER, AB-TEXT and AB-HEAD
• Text style romans.shx, 2.2 mm text height