Outdoor Network Cabinet Guide

A wireless link or camera network often ends at a pole, a wall or a tower base, far from any climate-controlled room. An outdoor network cabinet is the box that holds the switch, router, power supply and surge protection there. Heat, moisture and lightning cause most of the trouble, so this guide covers sizing, venting or sealing, and power and cable entry.

What goes in an outdoor network cabinet

List the contents before choosing a size. A typical WISP relay or camera node holds some mix of these:

• A PoE switch or PoE injectors feeding radios or cameras on the mast
• A router or small routerboard, and sometimes a fiber media converter
• A DC power supply, or a small UPS where the site needs ride-through
• Surge protectors for every cable that arrives from the tower or another building
• A ground bar, a terminal strip for AC, and room for service loops

Add free space for air and hands. A box packed to the door runs hotter and is slow to service from a ladder.

Pole mount network enclosure or wall mount

A pole mount network enclosure hangs from band clamps or bolts on a wood, steel or concrete pole, usually close to the radios it feeds. Check that the bracket is made for the pole’s diameter and that the pole’s owner allows the attachment.

A wall mount puts the cabinet on a building, where power and a ground connection are often closer. Pick the shadiest wall that still keeps cable runs reasonable, and mount it above snow and casual reach but within ladder height. Where the cabinet shares a mast with the radios, the wireless mast category lists mast sections in common diameters.

Where the heat comes from

Two sources heat a closed box: the sun on its skin and the electronics inside. The EPA’s guidance on cool roofs and solar reflectance explains the first: a surface with high solar reflectance absorbs less heat from the sun, which is why a light-colored or shaded cabinet starts its day cooler than a dark one in full sun.

For the second, count only the power that is actually turned into heat inside the box. PoE power sent up the mast is spent by the radios or cameras out there, not in the cabinet. A worked example, with assumed figures you should replace with the data sheets for your gear:

1. The switch’s own electronics draw 15 W.
2. It powers four radios on the mast at 10 W each, so 40 W leaves the box over the cable.
3. A power supply at an assumed 90% efficiency delivers that 55 W total, so it draws 55 / 0.9 = 61 W and loses about 6 W.
4. Heat released in the cabinet is about 15 + 6 = 21 W.

Put the same four loads inside the box, as with an access point in a nonmetallic enclosure, and the figure rises to about 61 W. Compare the total with the cooling data the enclosure or fan maker publishes, and check every device’s rated operating temperature against the hottest day the site sees.

Outdoor enclosure ventilation vs a sealed box

Outdoor enclosure ventilation trades protection for cooling. The right choice depends on the heat load, the dust and the water the box will face.

Any vent, fan or cooler must carry the same enclosure type as the box, or the box loses that rating. What each type keeps out is explained in our guide to NEMA enclosure ratings for outdoor gear, so match the vent to the type the site needs.

Condensation inside the box

A sealed box is not a dry box. The National Weather Service defines the dew point as the temperature to which air must be cooled to reach saturation. When a cabinet that was warm in the afternoon cools overnight, the air trapped inside can reach that point, and water forms on the coldest surface, often the door or the top.

• Use a rated breather vent or drain at the bottom so moisture can leave.
• Add a desiccant pack, and replace it on each service visit.
• On sites with wide temperature swings, a small thermostatic heater keeps the inside above the dew point.
• Bring every cable in from the bottom with a drip loop, and seal unused knockouts.

Surge protection and grounding at the cabinet

Every copper cable that arrives from a tower, a mast or another building can carry a surge into the box. Fit a surge protector to each Ethernet and coax line where it enters, and bond the protectors, the cabinet and any metal pole hardware to one ground bar. That bar connects to the site grounding system, never to an unbonded rod.

The AC side needs its own protection; our comparison of power conditioners vs surge protectors explains what a plug-in device does and does not stop. Have an electrician make the bond to the building’s grounding electrode system.

Power and PoE entry

Decide early whether the cabinet gets AC or runs on low-voltage DC from inside the building. An AC circuit and an outdoor receptacle are electrician’s work under the local code, with a lockable disconnect where the AHJ wants one.

• Size the switch or injectors to the loads with our PoE budget guide for IP cameras.
• For camera nodes, compare PoE, 12 VDC and 24 VAC options in how to power an outdoor security camera.
• If the node must stay up through outages, size runtime as in our UPS sizing guide, and check the battery’s rated operating temperature, since a hot cabinet is a hard place for batteries.

Locks, access and service

A cabinet on a pole in a parking lot invites curiosity. Choose a keyed or padlockable latch and avoid external switches or ports anyone can reach. Tamper switches wired to the alarm or monitoring system tell you when a door opens.

Make sure the door swings clear of the pole, label each cable at both ends, and leave a site sheet inside with the IP plan and power source.

Where to find enclosures and network gear

The wireless network enclosures category lists indoor and outdoor enclosures for radios, routerboards and network gear, and the network switches category lists switches for the same jobs. Both sit in the broadband and WiFi division. For pricing and ordering, contact your sales representative through the Bursma contact page, or open a Bursma dealer account.

Frequently asked questions