NCCER Electronic Systems flashcards
NCCER Electronic Systems · Build recall with a focused review session.
31 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Lockout/Tagout (LOTO)
- A safety procedure that isolates and locks all energy sources before servicing equipment. The authorized employee verifies a zero-energy state by testing, then applies locks and tags.
- Arc Flash Boundary
- The distance from energized equipment where incident energy equals 1.2 cal/cm², the threshold for second-degree burns. NFPA 70E uses it to select arc-rated PPE.
- Confined Space Atmospheric Limits
- Acceptable entry atmosphere: oxygen 19.5–23.5 percent, flammable gas below 10 percent LEL, and hydrogen sulfide and carbon monoxide within published exposure limits. Continuous monitoring is required.
- Ohm's Law and Power
- V equals I times R. Power P equals V times I, also I squared times R or V squared divided by R. These relationships size conductors and verify circuit loading.
- Parallel Circuit Rule
- Voltage is the same across all branches, and total resistance is the reciprocal of the sum of reciprocals. Total resistance is always less than the smallest branch resistance.
- Three-Phase Power Formula
- For a balanced three-phase load, real power equals the square root of three times line-to-line voltage times line current times power factor.
- Voltage Drop Formula
- Single-phase voltage drop equals two times K times current times length divided by circular mils, where K is 12.9 for copper and 21.2 for aluminum.
- NEC Article 760
- The National Electrical Code article governing fire alarm systems, including power sources, circuit classification, wiring methods, and separation from other circuits.
- TIA-568 Cabling Standard
- The commercial building telecommunications cabling standard defining categories, performance requirements, topology, and maximum distances for structured cabling systems.
- Riser Diagram
- A drawing showing the vertical distribution of systems between floors, including feeder sizes, panel locations, and riser pathways. It complements plan views.
- Horizontal Cabling Limit
- Permanent horizontal cabling is limited to 90 meters (295 feet). Adding patch cords at each end yields a maximum 100-meter channel.
- Cable Bend Radius
- The minimum curve a cable can tolerate without performance loss. Common practice is four times cable diameter for UTP and ten times for fiber during installation.
- Telecommunications Grounding Busbar
- A copper busbar in the telecommunications room bonded to the building grounding electrode system. It provides a common reference for racks, cable shields, and equipment.
- Projector Throw Ratio
- Throw distance divided by screen width. It determines lens selection and mounting location for a desired image size.
- HDCP 2.2 Compliance
- High-bandwidth Digital Content Protection required for 4K UHD protected content. Non-compliant splitters or displays cause blank screens or downscaled output.
- 70-Volt Distributed Speaker System
- A constant-voltage system using transformers at each speaker. Power taps set wattage per speaker, and total tap wattage must not exceed amplifier rating.
- Fail-Safe vs. Fail-Secure
- Fail-safe locks unlock on power loss, required for egress paths such as maglocks. Fail-secure locks remain locked on power loss, used on secure storage doors.
- OSDP Protocol
- Open Supervised Device Protocol for access control readers. It supports bidirectional encrypted communication (Secure Channel) and replaces legacy Wiegand interfaces.
- DORI Camera Standard
- A camera coverage metric: detect, observe, recognize, and identify. Identify requires roughly 80 to 100 pixels per foot at the target.
- Smoke Detector Spacing
- NFPA 72 requires no more than 30 feet between detectors on smooth ceilings and 15 feet from walls. A general rule allows 900 square feet per detector.
- Class A Fire Alarm Circuit
- A circuit that continues to operate with a single open or ground fault. It is required for many high-rise and life-safety applications.
- Fire Alarm Battery Backup
- Control units must support 24 hours of standby plus 5 minutes of alarm signaling, or 15 minutes for voice evacuation systems.
- Power over Ethernet Standards
- IEEE 802.3af delivers 15.4 watts, 802.3at delivers 30 watts, and 802.3bt delivers up to 90 watts at the power sourcing equipment.
- Single-Mode Fiber
- Fiber with a small core that carries one propagation mode, supporting long distances in kilometers. Used for campus and inter-building backbones.
- Private IPv4 Ranges
- Non-routable address ranges: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. They are used inside networks behind NAT devices.
- Pre-Functional Checklist
- A commissioning document verifying installation quality before energizing: power, grounding, terminations, labeling, firmware versions, and device addressing.
- Integrated Systems Test
- A commissioning test verifying cross-system sequences, such as fire alarm activating door release, HVAC shutdown, elevator recall, and public address override.
- Point-to-Point Verification
- Confirming every control system input and output matches the as-built drawings and sequence of operations before functional performance testing begins.
- Critical Path Method
- A scheduling technique identifying the longest sequence of dependent tasks. Activities on the critical path have zero float and determine project duration.
- Request for Information
- A formal document asking the designer to clarify ambiguous or conflicting drawings and specifications. Responses become part of the contract documents.
- Cost Performance Index
- Earned value divided by actual cost. A value above one means the project is under budget; below one means it is over budget.