How to find the right Commercial Door Power Supplies AI guide
Written by an AI model from its trained knowledge.
What the AI looks for in Commercial Door Power Supplies
- Voltage match
- Match the output to the lock's rated voltage, typically 12 or 24 VDC, and prefer field-selectable supplies. Under- or over-voltage causes weak holding force or coil overheating.
- Current headroom
- Add up the steady-state draw of every connected lock and reader and size the supply with spare capacity. Account separately for inrush on electric latch retraction devices. An overloaded supply sags, and locks then release or fail to retract.
- Fire alarm interface
- Include an FAI input that releases fail-safe locks when the fire alarm activates, where code requires it. Egress and life-safety codes require mag locks to drop on alarm.
- Battery backup and charging
- Include a built-in sealed lead-acid charger and size standby time to site requirements. Without backup, locks drop or stop operating during an outage.
- Individually protected outputs
- Use a power distribution board with fused or PTC-protected outputs per door, often switched by the access controller. One shorted door should not take down the rest.
- Listings and manufacturer requirements
- Look for UL 294 for access control power. Use the power supply specified by the exit-device maker for electric latch retraction hardware. Inspectors and hardware warranties depend on compatible, listed power.
Brands that matter
- Altronix: Very common access control power supplies and distribution boards.
- LifeSafety Power: Modular, networkable supplies built for access control enclosures.
- Securitron: Supplies designed around its own mag locks and strikes.
- Von Duprin: Dedicated supplies required for its electric latch retraction exit devices.
What to avoid
- Unregulated wall transformers for powering locks.
- Supplies without a fire alarm interface when driving fail-safe locks.
- Running electric latch retraction devices from a generic supply the hardware maker does not approve.
- Sizing to steady-state current only and ignoring inrush.
Questions
Can the access controller's own power output run the locks?
Only for very small, low-draw loads within its rating. Most installs use a separate lock power supply switched through controller relays or a power distribution board.