System Design, Integration, and Installation
This domain tests how requirements become a working, documented, and commissioned system. Expect questions on door schedules, riser diagrams, cable schedules, power calculations, integration points, installation practices, testing, and as-built documentation.
Design inputs
Start with the risk assessment, occupancy, egress requirements, privacy constraints, and operational workflows. Build a door schedule listing each opening, credential type, reader, lock, REX, door position switch, controller, and power source. Produce a riser diagram and cable schedule. Calculate voltage drop, lock current, reader current, and battery runtime. Identify integration points with fire alarm, video, intrusion, intercom, elevator, and visitor management.
Installation
Follow manufacturer instructions, NFPA 70 and local electrical codes, and listed equipment requirements. Separate power-limited and non-power-limited wiring where required. Protect cabling from tampering and environmental damage. Label devices and conductors. Ground and surge-protect appropriately. Commission every door: test grant, deny, REX, held-open, forced-open, fire release, power failure, and failover behavior.
Worked example
A 40-door project uses 16-door controllers. Three panels cover 48 doors, leaving spare capacity. The designer calculates that each door draws 0.35 A during unlock and 0.1 A at rest. A 40-door simultaneous release would draw 14 A, so the power supply and battery must be sized for that peak, not just the resting load. The installer separates controller network cabling from lock power, labels each circuit, and tests every door against the schedule before acceptance.
Traps
Do not design from a catalog without a door survey. Do not ignore voltage drop on long cable runs. Do not leave fire-alarm coordination to the end. Do not accept a system without documented commissioning and as-built drawings.