Blueprint & Schematic Interpretation Flashcards
7 cards from real CPI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Blueprint & Schematic Interpretation flashcards as text
On a blueprint, what does the abbreviation 'EQ SP' mean when used with a series of columns or studs?
Answer: Equal spacing between repeated elements
EQ SP (equal spacing) instructs the installer to distribute the specified number of elements evenly across the given span without individual dimension callouts.
A 'phantom' line (long dash, short dash, short dash pattern) on a technical drawing is used to show:
Answer: Alternate positions or repeated/removed features
Phantom lines indicate an alternate position of a moving part, a repeated pattern detail, or a removed section that is referenced but not part of the current assembly.
On a P&ID, a control valve with a diaphragm actuator and spring-return is symbolized by:
Answer: A body symbol with a diaphragm circle and spring symbol on the actuator
Control valves on P&IDs combine the valve body symbol with an actuator symbol; a circle represents the diaphragm and a spring symbol indicates spring-return action.
What is meant by the term 'tolerances' as shown on a blueprint dimension?
Answer: The permissible variation from the stated dimension
Tolerances define the acceptable upper and lower limits of a dimension, ensuring parts fit and function even with minor manufacturing variation.
When a wiring diagram shows a component labeled 'CR1' with several sets of contacts labeled 'CR1-1,' 'CR1-2,' etc., this indicates:
Answer: One control relay whose contacts appear in different parts of the circuit
A single control relay (CR1) can have multiple contact pairs shown in different rungs; all contacts labeled CR1-x open or close together when the coil is energized.
On a mechanical assembly drawing, a 'balloon' callout with a number inside and a leader arrow pointing to a part refers to:
Answer: The item number in the accompanying parts list or bill of materials
Balloon callouts link each part in the drawing to its corresponding row in the bill of materials (BOM) by matching item number.
Which symbol on an electrical one-line diagram represents a two-winding power transformer?
Answer: Two interlocking circles side by side
A power transformer on a one-line diagram is shown as two adjacent circles (or semicircles), each representing one winding, connected to their respective bus lines.