How to Choose a PoE Switch for IP Surveillance Projects (8/16/24-Port)

Choosing a PoE switch for IP cameras comes down to three numbers. First, the PoE budget: add up each camera’s wattage, multiply by 1.20 for headroom, and compare the result with the switch’s total budget — not with its port count. Second, the port count: 8 ports for a small site, 16 for a mid-size building, 24 for a campus or a logistics park. Third, the uplink: copper inside a building, fibre beyond 100 m, and a media converter when you need to extend a copper segment that is already installed. This guide gives you the formula, a fully worked example, and the Winsure models that fit each size.

1. PoE budget calculation: the formula, and the mistake it prevents

This is the step that decides the model, and the one most often done by counting ports instead of watts. A port count tells you how many devices you can plug in. It says nothing about how much power the switch can actually deliver.

The formula

Three quantities are involved, and they are all different:

For the per-port figures: a camera needs a port rated at least as high as its own draw, so a 25 W PTZ camera needs a PoE+ (802.3at) port, not an 802.3af one. All the new Winsure PoE models are IEEE 802.3af and 802.3at compliant and support up to 30 W per port, so both classes of camera are covered by the same switch.

Worked example: nine cameras on one PoE switch

Take a small site with nine cameras. The wattages below are typical figures — always use the wattage on your camera’s own datasheet, because PTZ models in particular vary a lot once the heater and blower are counted.

Now compare 132 W against the three models:

The lesson in the first row is the whole point of this section. An 8-port switch with eight PoE ports looked like a fit on port count alone. On budget it was 12 W short of the requirement — a margin that would have been invisible at quotation stage and obvious in the first week of operation, when the last camera in the sequence refuses to boot.

Figure 1 — The PoE budget calculation: camera demand on the left, the total budget of the 8, 16 and 24-port models on the right.

Why 20 % headroom, and when to take more

The 20 % is not padding for its own sake. It covers three real effects:

· Inrush at cold start. After a power cut, every camera powers up at the same instant. The combined inrush current briefly exceeds the steady-state load, and a budget with no margin is the budget that trips.

· The camera you add later. Sites grow. A budget at 100 % of capacity at handover is a switch you have to replace the first time someone adds a camera to the same cabinet.

· Nameplate versus real draw. A camera’s datasheet figure is usually quoted at 25 °C. Add a heater and a blower for a winter night and the draw rises.

Three traps that break a PoE budget

· Reading the port count as the budget. Eight ports × 30 W is 240 W of demand. Compare the total, not the ports.

· Ignoring voltage drop. PoE supply distance is 0–100 m on these models, and a 30 W load on a full-length run loses voltage along the way. Keep high-power devices — PTZ cameras in particular — closer to the switch, and use good cable.

· Forgetting the non-camera PoE devices. Access points, intercoms, and door controllers draw from the same budget. Add them to the sum before you pick the model.

2. 8, 16 or 24 ports: matching the switch to the site

Once the budget is under control, the port count is straightforward. Here is the range mapped to site size, with the PoE budget and port speed of each model.

Choosing the 8-port model

The 8-port is the right answer more often than integrators expect, because it also carries a 2 × gigabit uplink and one fiber port. Camera traffic runs at 100 Mbps into the switch and leaves at gigabit, so a single 8-port unit can serve a shop or a small office without any compromise. It is also the smallest of the three at 190 × 135 × 36 mm, which matters when the only available space is a small wall-mounted enclosure.

Choosing the 16-port model

The 16-port is the middle of the range and the most common choice for a mid-size building: 200 W of budget, 16 camera ports, the same gigabit uplinks and fiber port. Its 200 W fits roughly eight cameras plus a couple of PTZ units with room to spare. If a project is between two sizes, this is usually the safer pick — it leaves headroom in both budget and ports.

Choosing the 24-port model

The 24-port is the only one of the three that is gigabit on every PoE port, and it carries the largest budget at 400 W. Choose it when a single switch aggregates a large camera count, when the same uplink also carries workstation or NVR access, or when a site may grow past 16 cameras. Note it uses 2 × SFP slots rather than a fixed fiber port, so the fiber module is a separate line item in the RFQ.

Two 16-port switches instead of one 24-port

Worth considering before you default to the biggest model. If the cameras are spread across two buildings, two 16-port units on a fiber link usually cost less in cable than one 24-port central switch with long home runs, and a single failure takes out one half of the site rather than all of it. The trade-off is two points of management instead of one.

When the cabinet is outdoors or on a factory floor

All three models above are rated −10 ~ 65 °C, or −20 ~ 65 °C for the 8-port, and are designed to sit in a ventilated indoor panel. If the switch has to live in a sealed outdoor cabinet, a combiner box or a workshop, use the industrial managed PoE models instead — they are rated −40 ~ 75 °C, IP40 aluminium, fanless and DIN-rail mounted, with PoE+ and up to 8 RJ45 ports plus fiber:

· wsCom1005LG-2GSFP-4G/DC-INT — 2 fiber + 4 × gigabit PoE ports, DC 48 V

· wsCom3010G-2GSFP-8G/DC-INT — 2 fiber + 8 × gigabit PoE ports, DC 12–55 V

· wsCom3028G-4GSFP-8G/DC-INT — 4 fiber + 8 × gigabit PoE ports, DC 12–55 V, for a ring

If a project needs more than eight PoE ports inside an unconditioned cabinet, tell us at quotation stage: the usual answers are to condition the cabinet, to split the camera load across two industrial switches, or to move the aggregation switch into the climate-controlled room and keep only the industrial units outdoors.

3. Uplink: copper, SFP, or a media converter

The last decision is how the switch reaches the rest of the network. Distance settles it.

Copper up to 100 m

Inside a building, copper is still the cheapest and simplest answer, and it carries power as well as data. The limit is 100 m, and the practical advice is to treat the last 20 m as the risky part: a 30 W device on a full-length run loses voltage along the way, and cheap cable makes it worse.

Fibre beyond 100 m

Once the run exceeds 100 m, convert to fibre. Both the 8-port and 16-port models include a fixed 1 × 9 fiber port (ST / SC / FC options), which is the cheapest way to get one long link out of the cabinet. The 24-port model instead provides 2 × SFP slots, which let you change distance or wavelength later by swapping a module — useful when the fibre route is not finalised at order time. On the industrial range the optical modules are sold separately, so they belong in the RFQ.

On the fiber side the industrial range covers 0.55 / 2 / 20 / 40 / 60 / 80 / 100 / 120 km, single-mode dual-fiber by default, with single-fiber BiDi at 1310 / 1550 nm as an option. On a long surveillance route, BiDi halves the fibre count, which is a real line item across a whole site.

Media converters, to extend copper you have already installed

Sometimes the copper is already in the ground and only the last hop is too long. That is a media converter job, not a new switch:

· wsCom1005-1GST-4G/DC-INT — 4 × gigabit RJ45 plus one fiber port, 4 kV surge protection on the ports, DC 12–57 V, ST / FC / LC options. It also supports PoE power supply, so a camera or access point at the far end can be fed from it.

· wsCom1000-1GST-1G/DC-INT — one RJ45 plus one fiber port, single-mode single-fiber at 1550 nm over 20 km. The single-camera long hop.

For the industrial media converter range in full, see the industrial-grade fiber optic transceivers, and pair them with fibre optic patch cords and a termination box or ODF from the same order.

4. PoE switches and fiber transceivers in the Winsure range

Winsure builds industrial and commercial Ethernet switches, optical transceivers and fiber accessories in its own factory in Shenzhen, where it has run OEM and ODM production for overseas partners since 2016. Twenty switch models and fourteen transceiver models are held in stock, and CE, FCC and RoHS certificates ship with each batch. The company holds ISO 9001, ISO 14001 and ISO 45001.

The PoE models split across two families. The commercial PoE switches above are the right choice for a ventilated indoor panel; the managed industrial switches in the industrial-grade range cover the same job in a −40 ~ 75 °C cabinet.

5. What to send us for a written quote

1.The camera list with quantity and the wattage per camera from the datasheet, including any PTZ units.

2.Any non-camera PoE devices: access points, intercoms, door controllers.

3.How many ports you want spare at handover.

4.The longest cable run, and whether fibre already exists on site.

5.Where the switch will be mounted — ventilated indoor panel, or a sealed/unconditioned cabinet.

6.Whether the switch must also carry data traffic (NVR or workstation access) on the same uplink.

7.Whether you need managed features: VLAN separation, QoS, port mirroring, SNMP, ring redundancy.

8.Certifications required and any project-specific standard.

9.Quantity, target delivery date, and whether you need OEM or ODM branding.

Send it to info@cnwinsure.com or WhatsApp +86 134 2874 4818. An engineer replies with a written quote within 24 hours, and OEM or ODM production is available with your logo, your label and your carton.

Frequently asked questions

1.How do I calculate the PoE budget for a surveillance switch?

Add up every powered device: camera wattage multiplied by quantity. Multiply that total by 1.20 to add 20 % headroom, then compare the result with the switch’s total PoE budget — not with its port count. In the worked example above, six 4 MP domes at 8 W, two PTZ cameras at 25 W and one thermal bullet at 12 W draw 110 W; with 20 % headroom you need 132 W, so an 8-port switch with a 120 W total budget is undersized even though it has exactly eight PoE ports.

2.How many cameras can an 8-port PoE switch power?

Eight, if the total budget allows — and that is the part people miss. A switch with eight PoE ports and a 120 W total budget cannot serve eight cameras drawing 30 W each, because that is 240 W of demand. In practice an 8-port 120 W unit suits four to six typical 4 MP fixed cameras, or a mix that includes one or two PTZ cameras. Count the watts, not just the ports.

3.Do I need a 24-port PoE switch with gigabit ports, or is 100 Mbps enough?

For camera traffic, 100 Mbps per port is far more than a 4 MP or 8 MP stream needs, which is why the 8- and 16-port Winsure PoE models use 100 Mbps PoE ports with gigabit uplinks: cameras run at 100 Mbps and the aggregated video leaves at gigabit. Choose the gigabit 24-port model when one switch aggregates a large camera count, or when the same uplink also carries data traffic such as NVR or workstation access.

4.Can I run PoE beyond 100 m?

Not over copper. The PoE standard and the switch datasheets both specify a supply distance of 0–100 m, and voltage drop makes the last part of that run the weakest. Beyond 100 m, convert to fibre: use an SFP module or the fixed fiber port on the switch, or add a media converter to extend an existing copper segment. The transceiver range covers single-mode dual-fiber by default with single-fiber 1310 / 1550 nm on request, and 3 km and 20 km links, while the industrial switch range covers 0.55 to 120 km on the fibre side.

5.What is the difference between PoE (802.3af) and PoE+ (802.3at)?

802.3af, usually just called PoE, delivers up to 15.4 W at the port. 802.3at, called PoE+, doubles that to 30 W at the port, which is what PTZ cameras, heaters, blowers and multi-sensor cameras need. The Winsure PoE models are IEEE 802.3af and 802.3at compliant and support up to 30 W per port, so a single model covers both classes of camera.

6.Do I need a managed PoE switch for a CCTV installation?

If the switch only feeds cameras and there is nothing to configure, unmanaged is enough. Managed becomes worthwhile when the same switch also carries control or data traffic and you need VLAN separation between the CCTV network and the rest, when you want QoS so a burst of video cannot delay control traffic, when you need port mirroring to diagnose a problem camera, or when the switch is part of a fiber ring that has to survive a single fiber cut.

Send us your camera list and we will size the switch. Give us the quantity and wattage of each camera, the longest cable run and where the switch will be mounted, and we will come back with a written quote within 24 hours — including the correct fibre modules and power supply, so nothing arrives missing.

Browse the PoE switch range or learn more about Winsure.