01
Start with endpoints and their functions.
Eight sockets do not necessarily mean eight PoE outputs or identical power on each. List endpoint ID, location, exact model, function, supported power input and proposed port. Add uplinks and reserved sockets. A physically free port is not automatically spare power.
Keep unknowns in the schedule. Do not assign a similar product’s consumption to an undocumented old camera. Obtain its identity and manual, then validate the pairing. Inovexia can help prepare references and accessories; installation limits must remain traceable through handover.
02
Four independent checks before selecting a switch.
Scroll the table horizontally to compare all three columns.
| Check | Compare | Avoid |
|---|---|---|
| Compatible mode | Documented type, class and power mechanism on both sides. | Assuming an RJ45 socket or PoE label is enough. |
| Port limit | Endpoint requirement/allocation on its actual port. | Using total budget to excuse an insufficient port. |
| Shared budget | Summed source-side allocations for the installed supply. | Adding only favourable average consumption. |
| Complete chain | Source, cable, connections, endpoint and required functions. | Confusing power-on, link-up and a working service. |
03
Fill the columns that prevent surprises.
Value and measurement point
State whether power is endpoint-side or source-side and typical, maximum or allocated. Account for link losses at the correct boundary, not twice. An idle observation does not validate every function or condition.
Operating modes
For cameras, check supported IR, heaters or motors and documented values. For access points, identify any power-dependent function limits. Record required operation without copying a generic product-family number.
Source and cabling
Record the actual switch/injector model and supplied power unit. Verify links and installation conditions. A passive injector is not a negotiated supply: do not force modes or connect devices to guess compatibility.
Expansion and failure
Name future equipment and reserved ports. Confirm priorities and behaviour during shortage or restart. Justify reserve from the project rather than presenting one percentage as universal.
04
A fitting total can still hide an insufficient port.
ILLUSTRATIVE EXAMPLE
Fictional case: allocations are already source-side, with link losses assumed included. Four cameras need 15 W each, two access points 25 W each and one intercom 12 W. These are neither product specifications nor normative PoE class values.
Reject the first budget
The 7 endpoints total 122 W. A 120 W proposal fails even if each port fits. Across 8 sockets with one dedicated copper uplink, no socket remains free. Neither port count nor total alone is enough.
Assess the addition separately
Another fictional option has a 180 W total, free ports and a 30 W per-port limit. Adding a camera needing 45 W source-side gives 167 W: the total fits but the port fails. Redesign the solution; do not combine sockets without an authorised design.
Keep the remaining checks
Even with fitting capacities, compatibility, actual supply, link, environment and required service still need validation. Handover checks intended modes too. This arithmetic excludes the switch’s own consumption from UPS sizing; that is a separate boundary.
Documentary example only. No catalogue equipment is declared compatible. Source-side values must not be reinterpreted as measured endpoint consumption.
05
Match the schedule to the handed-over installation.
Verifiable labels
Port, cable and endpoint labels match the final schedule. Record substituted references and validate them again. A neat but unlabelled rack leaves expansion and servicing uncertain.
Modes and outcome
Under an authorised procedure, check agreed functions, alerts and recovery. Record omitted tests. Low instantaneous power or an active Ethernet link does not prove night operation, recording or calling.
Configuration and follow-up
Keep configuration, schedule revision and change ownership. Recalculate total and per-port limits before adding equipment. Administrator access stays in the agreed secure channel, never in a shared quote.
06
A brief that makes two proposals comparable.
Provide endpoint/port schedules, available documents, unknowns and planned expansion. Request separate main equipment, supply, any injectors, accessories and checks. Inovexia’s commercial selection and integrator validation are complementary; matching catalogue categories alone approves no assembly.
07
Questions to ask before connecting.
Do eight PoE ports support eight maximum loads simultaneously?
Not necessarily. Shared budget and the actual supply may limit it. Check port count, individual limits and documented total together.
Can I size from typical camera consumption?
Not as sole evidence. Identify its conditions, required modes and documented maxima. Reserve and allocation must match the equipment and measurement boundary.
Will any PoE injector work with any PoE camera?
No. Exact reference, power mechanism, voltage and supported functions must match. Do not assume negotiation on a passive model; verify before connecting.
Does PoE budget directly size the UPS?
No. Switch mains input, losses and other loads are a different boundary. If input already includes endpoints, do not add them again. Check W, VA and runtime separately.
Does a network light prove the service works?
No. Check the expected result: recording, wireless access or calling. Keep power, data link and service as three separate checks.
Technical sources
External reading references. These documents explain principles; they do not certify catalogue products or their combination.
- Typical and maximum power consumption in Axis camerasAxis Communications · Sources consulted on
- PoE Availability and ModesUbiquiti · Sources consulted on