Power Supply FAQ

The questions buyers ask most about power supplies — answered with links to our deep-dive guides and product pages.

FAQPower Supply Knowledge

Power Supply FAQ

Wall-mount or desktop power adapter — which should I choose?

Wall-mount adapters plug straight into an outlet and save desk space for routers, ONUs and small IoT gear; desktop adapters sit in an enclosure with a separate DC cord and suit higher wattage or where the outlet is far. See the wall vs desktop guide.

12V or 24V power supply — which should I specify?

12V covers most LED, CCTV and low-power gear; 24V is preferred for longer cable runs (less voltage drop) and DIN-rail control systems. Always match the load's nameplate voltage.

What wattage does PoE 802.3af/at/bt actually deliver?

802.3af = 15.4 W (Type 1), 802.3at = 30 W (Type 2, "PoE+"), 802.3bt = 60 W (Type 3) or 90 W (Type 4, "PoE++"). Budget is limited by the switch's total PoE wattage, not just per-port.

How do I size a DIN rail power supply (why add headroom)?

Total the load current at the rail voltage, then add 20–30% headroom for inrush, capacitor charging and future expansion. See the DIN rail selection guide and the DIN rail PSU range.

What is N+1 redundant DIN rail power and when do I need it?

Two or more parallel DIN rail units share the load so one can fail without dropping the system — essential for PLC cabinets, security and building automation. Use it wherever an unplanned shutdown is unacceptable.

What IP rating / enclosure do I need for an industrial power supply?

Indoor cabinets: enclosed metal with convection cooling (IP20). Harsh or wash-down areas: IP54–IP67 sealed units. Pick by ambient dust, moisture and temperature; see industrial enclosed PSU.

Can you build a custom AC/DC power supply for my product?

Yes — XGW does OEM/ODM from 500 units: custom output voltage/current, connectors, dimming, housing, label and packaging. See custom AC/DC.

How do I power CCTV cameras — 12V adapter, 24V or PoE?

Fixed cams: 12V DC adapter or a centralized 12V fused box; long runs: 24V AC; IP cams: PoE (802.3af/at). Keep a UPS on the NVR + switch. Full detail in the CCTV Power guide.

What certifications should a power supply have for export?

UL (North America), CE (EU), CB (international), plus RoHS and regional marks (PSE Japan, SAA Australia). XGW products carry IEC/CE and are built under ISO 9001.

What is the difference between a power adapter and a power supply?

A power adapter is a small external AC/DC brick (wall or desktop) for one device; a power supply is the broader term, including enclosed, DIN-rail, PoE and custom units that feed one device or a whole system.

Related products

Guides & deep-dives

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Applications

Control & automation

DIN rail and enclosed PSUs power PLCs, sensors and actuators across the plant.

Network & CPE

CPE and desktop adapters feed routers, gateways and PoE midspans.

Surveillance

CCTV adapters run camera clusters and NVRs with headroom for PTZ inrush.

Custom OEM

Open-frame and custom AC/DC units drop into branded equipment with tuned specs.

Industrial PSU vs Adapter vs Open Frame: Which to Specify

The right family depends on whether the load is fixed equipment, portable gear or embedded OEM product.

Industrial PSU vs adapter vs open frame
Use caseFixed industrial gearPortable / indoorEmbedded OEM
Output24V/48V, 75W-1000W5V-24V, 1A-10A10W-500W
ProtectionIP20, surge, boostBasicHost-dependent
Best forPanels, machinesRouters, hubsAppliances

Specify an industrial PSU for panel and machine power, an adapter for portable gear, and open frame for products that provide their own enclosure.

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