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Access Control Power Supply
An access control power supply turns building AC power into the regulated 12 or 24 volt DC that maglocks, electric strikes, electrified locks and latch retraction exit devices need. Shop Von Duprin/Schlage PS900 supplies and option boards, Securitron AQD, SDC 600 Series, PHI Precision RPSMLR2 and ELR supplies, RCI DKPS supplies, backup batteries and power transfers.
What does an access control power supply do?
An access control power supply converts 120 or 240 VAC from the building into low voltage DC for door hardware, and distributes it to one or more doors. Better units add fused or protected outputs, relays that switch each lock, a fire alarm input that releases locks on alarm, and battery backup. Most supplies in this category are field selectable between 12 and 24 VDC, so one model can serve different locks.
How to size a power supply: volts, amps and inrush
Size the supply by voltage first, then by current. Match the voltage to the locks (12 or 24 VDC), then add up the current draw of every device on the supply and choose a supply rated above that total, so it does not run at its limit. Motorized or solenoid latch retraction exit devices draw a high current when they retract, called inrush, and need a supply built for it: the Von Duprin PS914 is listed at 4A with 16A inrush, and PHI Precision lists the RPSMLR2 as the recommended supply for its MLR (motorized latch retraction) exit devices. Check each device's cut sheet for its current draw.
| Power supply | Output (as listed) | Notes |
|---|---|---|
| Von Duprin/Schlage PS902, PS904, PS906 | 2A, 4A, 6A at 12/24 VDC field selectable | Base supplies; option boards for relays, fused or PTC outputs, fire alarm, battery backup, key lock |
| Von Duprin PS914 | 4A with 16A inrush at 12/24 VDC | For latch retraction exit devices |
| Securitron AQD1, AQD2, AQD6 | 1A, 2A, 6A at 12/24 VDC | Switching supplies; 8F8R versions with 8 fused outputs, relays and fire trigger |
| Securitron BPS-12-1, BPS-12-3 | 1A, 3A at 12 VDC | 12 volt only |
| SDC 602RF, 631RF, 632RF, 634RF, 636RF | 1A to 6A at 12/24 VDC field selectable | Class 2 output on 602, 631, 632 |
| PHI Precision RPSMLR2, RPSMLR2BB | See listing | For PHI MLR exit devices; BB has backup battery card and storage |
| PHI Precision ELR151 to ELR154, PS161-6 | See listing | ELR with 1 to 4 control modules for exit devices |
| RCI DKPS-2A, DKPS-4A | 2A, 4A at 12/24 VDC | 8 outputs |
| Adams Rite PS-EXIT | See listing | For 8000 and 3000 Series with LR/MLR |
Mag lock power supply: what to check
A maglock needs constant DC power to stay locked, so the supply must be sized for continuous load and wired to release on a fire alarm where the code requires it. Look for a supply with a fire alarm relay or input, such as Von Duprin/Schlage models with FA in the name or Securitron AQD 8F8R supplies with a fire trigger. Add battery backup if the door must stay locked during a power cut, and remember that a fail safe maglock unlocks when power is lost.
Option boards: relays, fused outputs and battery backup
The Von Duprin/Schlage PS900 system is modular: a base supply accepts option boards. The catalog lists 900-2RS and 900-4RL relay boards, 900-4R independently controlled relays, 900-8F fuse protected and 900-8P PTC protected output boards, FA versions with fire alarm input, the 900-BB battery backup board, 900-BBK battery backup kit with two 7A/hour batteries and 900-BAT batteries. Securitron lists the PDB-8F8R power distribution board, and SDC lists the RB12V7 12V/7Ah backup battery.
Getting power to the door: power transfers
A lock in the door needs wires that survive the door opening and closing, which is the job of a power transfer. SDC lists the PT-5 concealed power transfer, the PTM-2 and PTM-10 heavy duty transfers, the PT-2U and PT-3V armored power transfer loops and the WPT wireless power transfer. Electric hinges are another option; see electrified hinges.
Exit device sequencers and door control boards
On pairs of doors or doors with an automatic operator, the order of events matters: the latch must retract before the operator opens the door. SDC lists the EMC exit device sequencer module and the CR4 door control board for power supplies to manage that timing.
Most requested power supplies
The power supplies our customers look up most often right now:
- PHI Precision RPSMLR2BB Power Supply, MLR Kit with Backup Battery Card
- PHI Precision RPSMLR2 Power Supply, MLR Kit
- Securitron AQD2 Switching Power Supply, 12/24 VDC, 2 Amp
- Von Duprin/Schlage PS902-2RS Power Supply with 2 Relay Board
Shop by model: Von Duprin/Schlage PS902.
Related categories: maglocks, electric strikes, push to exit buttons and exit device power supplies.
What to have ready when ordering a power supply
- Voltage of each lock (12 or 24 VDC) and its current draw, including inrush for latch retraction.
- Number of doors and devices on the supply.
- Fire alarm release required, and battery backup required.
- Outputs needed: relays, fused or PTC outputs, timers.
- How power reaches the door: power transfer or electric hinge.
For a step-by-step sizing method, read our guide to choosing an access control power supply.
Planning several doors? Request a quote, and schools and agencies can submit a government or school PO. Orders placed before 3:00 p.m. ET on business days ship the same day after card approval, and ground shipping is free on orders of $450+. Send us the lock models and we will help size the supply: call 718-814-6300.
The tables and selection notes on this page are compiled by National Lock Supply from manufacturer catalogs and product listings. Last reviewed: November 2026.
Frequently Asked Questions
Can one power supply run several doors?
Yes, if its rating covers the total current and it has enough outputs. Supplies with distribution boards, such as the PS900 with 900-8F fuse protected outputs or the Securitron AQD 8F8R with 8 fused outputs and relays, are designed for several doors with separate protection on each output.
Who should install an access control power supply?
A licensed electrical or low voltage contractor. The power supply's 120 VAC input is wired to a building circuit, and a fire alarm interface usually has to be connected and approved together with the fire alarm contractor. The low voltage outputs to the locks are then wired to the door hardware and the access control panel.
Why does my maglock not hold when the power supply is on?
Check that the output voltage matches the voltage the maglock is set for, 12 or 24 VDC, that the fire alarm input or a control relay is not releasing the lock, and that the armature plate meets the magnet squarely. Long wire runs with thin wire can drop the voltage below what the lock needs.