Reading Electrical Blueprints Flashcards
7 cards from real CEA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Reading Electrical Blueprints flashcards as text
On an electrical blueprint, 'EMT' in a conduit note refers to:
Answer: Electrical Metallic Tubing
EMT stands for Electrical Metallic Tubing, a thin-wall metal conduit commonly specified on commercial drawings.
A blueprint note reads '3-#12 AWG in ¾" EMT.' How many conductors are in this conduit?
Answer: 3
The '3' prefix indicates three individual conductors—typically two hots and a neutral, or two hots plus a ground.
On a single-line diagram, a diagonal line through a conductor symbol indicates:
Answer: The number of conductors in that run
Diagonal tick marks across a single line indicate the number of conductors bundled in that run.
What does the abbreviation 'MLO' mean in a panel schedule on blueprints?
Answer: Main Lugs Only
MLO means Main Lugs Only, indicating a panelboard without a main circuit breaker—fed from an upstream device.
Which scale is MOST commonly used for electrical floor plans in commercial construction?
Answer: 1/4" = 1'-0"
1/4" = 1'-0" is the most common scale for commercial electrical floor plans, providing enough detail while fitting on standard sheets.
On a blueprint, 'GFI' or 'GFCI' next to a receptacle symbol means the device:
Answer: Has ground fault circuit interrupter protection
GFCI indicates the receptacle includes ground-fault circuit-interrupter protection, required in wet or damp locations.
A blueprint detail showing conduit bending radius requirements is MOST likely found in:
Answer: The electrical specifications or detail sheets
Conduit bending and installation details are specified in the electrical specification sections or dedicated electrical detail sheets.