Hotel Head-End Overload and Fire Relay Mismatch at Turnover
You are the commissioning agent on a 120-room hotel project. The owner adds 14 IP cameras to an existing 32-camera system two weeks before turnover, bringing the head-end to 46 cameras on one 48-port PoE+ switch with a 370 W PoE budget and a single 1 Gbps uplink shared with 60 guest Wi-Fi access points. Existing cameras draw 7.5 W each; the new models draw 12.5 W. The fire alarm contractor wired the alarm relay to the access-control panel using a normally open contact, but the access-control panel expects a normally closed, supervised input for the mag-lock release. The owner refuses to sign the punch list until "the cameras, Wi-Fi, and locks all work at the same time," and the hotel opens in 12 days.
1. Analyze the PoE load and port count. What do you recommend?
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PoE load: existing 32 × 7.5 W = 240 W; new 14 × 12.5 W = 175 W; total 415 W against a 370 W budget - the switch is overloaded by 45 W. Also 46 cameras use 46 of 48 ports, leaving no spares. The PoE budget is a hard limit, not a suggestion.
Remedies: split the cameras across a second PoE switch, add PoE midspans/injectors for the new cameras, use a switch with a higher PoE budget, or reduce the new camera count/resolution. I would not simply plug them in; over-subscription causes dropouts and reboots that will be blamed on the integrator. I would also check UPS runtime at the new load and the closet's circuit capacity.
2. Evaluate the network capacity and recommend the test plan the owner is demanding.
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Uplink: 46 cameras × 8 Mbps ≈ 368 Mbps of video, plus 60 guest access points sharing the same 1 Gbps uplink with no QoS. That is not necessarily a hard failure, but video and guest traffic will contend; without VLAN separation and QoS, guests can starve the NVR and cause recording gaps. I would require separate VLANs for video, access control, and guest Wi-Fi, QoS prioritizing video and access control, and a review of uplink and NVR throughput.
Then I would run the soak test the owner is asking for: all three systems active simultaneously, measuring packet loss, jitter, camera recording continuity, failover, and lock release response - not just "can I see a picture." The results become the acceptance criteria.
3. How do you handle the fire alarm relay discrepancy and the 12-day schedule?
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The fire-alarm relay is wired normally open, but the access panel expects a normally closed supervised input. That is a life-safety interface and cannot be left as "it works when we jumper it." I would stop the sign-off, document the discrepancy, and require the fire alarm contractor to provide the correct supervised NC contact or listed relay, and the access-control programmer to verify supervision and fail-safe release. Then test normal, alarm, trouble, and power-loss conditions.
On the 12-day schedule, I would issue a written change order for the added cameras (labor, switch, programming, testing) and a separate deficiency notice for the fire relay. I would propose phased acceptance: cameras and Wi-Fi can be accepted separately once tested, but the lock release cannot be accepted until the interface is corrected and witnessed. Customer relations means being clear about what is not safe to accept, not signing a false "everything works" letter.