Telecom Cabinet & Outdoor Enclosure Cooling Fan
Base-station cabinets, RRU enclosures, roadside cabinets and edge data cabinets all rely on filtered forced air, and they are expected to keep doing it for fifteen years without a maintenance visit. Dust, sun load, vibration from the mast and a 48 V DC bus define the specification. We build 92–280 mm AC, 24/48 V DC and EC fans for this duty, along with the filters and guards that go with them.
Part of: cooling fan applications · also relevant to power supplies and EV chargers.
What telecom enclosure cooling demands
- Airflow against a filter, not in free air. A loaded dust filter plus a rain louvre can add 50 Pa. Sizing on free-air CFM is the most common reason a cabinet runs hot in its second summer.
- 24 V or 48 V DC from the site battery. Most outdoor cabinets have no mains. The fan has to start reliably at the low end of the battery range and tolerate a long, thin DC lead without stalling.
- IP55 with a serviceable filter. The enclosure is protected, but only while the filter is clean — which means the fan and filter have to be designed as one service item.
- −40 to +70 °C and a fifteen-year horizon. Wide-temperature lubricant, dual ball bearings and a frame that does not yellow or crack under UV.
Fan sizes and voltages for telecom cabinets
| Frame | Typical position | Voltage | Models |
|---|---|---|---|
| 92–120 mm | small RRU cabinet, remote radio unit | 24 / 48 V DC | DC 9238, DC 12038 |
| 120 mm AC | indoor rack, small outdoor cabinet | 110 / 220 V AC | AC 12038 |
| 172 mm | outdoor cabinet, 2–3 fan wall | 48 V DC / 220 V AC | DC 17251, AC 17251 |
| 225–280 mm | equipment shelter, equipment room | 220 / 380 V AC | AC 22580, DC 28080 |
| Accessories | filter and finger guard to match | — | 120 mm PBT filter, 120 mm guard |
Why cabinets overheat in year two
- No filter, or a filter nobody replaces. Dust blankets the fin stack, the pressure drop doubles and the fan quietly moves half the air it did when it was installed.
- The fan is replaced, the filter is not. The new fan works against the old restriction and fails early, which is read as a fan quality problem rather than a maintenance one.
- Voltage drop on a long DC lead. A 48 V fan on a thin 8 m lead may see less than 40 V at start-up. Specify the lead length and we will confirm the start-up current against it.
How to specify a cabinet fan
- Heat load in watts and the maximum internal temperature the electronics allow.
- Filter class and louvre type, so the pressure drop is known before the fan is chosen.
- Available rail: 24 V or 48 V DC, or 110/220 V AC, and the minimum voltage at the fan.
- IP level and whether washdown or coastal salt spray applies.
- Service interval you can realistically support, which sets the filter area and the fan margin.
Questions from cabinet and shelter builders
DC or AC for an outdoor cabinet?
DC where the cabinet runs from a 24/48 V site battery — it avoids an inverter and works during a mains outage. AC where mains is available and the heat load is large, because a 225 mm AC fan delivers more airflow per unit of cost. Many designs use a DC fan wall for normal operation and an AC exhaust fan for peak summer.
Do you supply the filter and guard with the fan?
Yes. PBT fan filters in 80, 120 and 150 mm, steel and plastic finger guards in 40, 80, 120 and 150 mm, and 172 mm window filters for larger fan walls. Shipping them as a kit keeps the pressure drop and the service item consistent.
Can you supply a 48 V fan with an alarm output?
Yes, FG tachometer and RD locked-rotor alarm are available on our DC fans. In a cabinet that is visited twice a year, the alarm is what turns a failed fan into a scheduled replacement instead of an outage.
Related: EV chargers · UPS & power supplies · AC axial fans
Send the heat load, the filter specification and the site voltage, and we will size the fan wall for a half-blocked filter rather than a clean one. Request a selection.