Altronix LPS3C24X: Power Supply for a Maglock Door
Posted by Kent on 16th Aug 2026
The badge reader on the wall does not power the lock. That trips up more people than anything else on an access-control job. Reader, controller, maglock or electric strike, request-to-exit device, and none of it moves until something feeds it clean DC and keeps feeding it when the building goes dark. That job belongs to the power supply, and the one I hand across the counter for it is the Altronix LPS3C24X linear power supply.
What the LPS3C24X actually is
A 24VDC linear supply, filtered and electronically regulated, rated 2.5 amp continuous, with short circuit and terminal overload protection, AC input and DC output LEDs, and a lifetime warranty. The enclosure runs 15.5"H x 12"W x 4.5"D with 1/2" and 3/4" combination knockouts and holds up to two 12VDC batteries inside.
The battery side is what makes it an access-control supply. Built-in charger for sealed lead acid or gel batteries, maximum charge current .5 amp, fused battery protection, automatic switch over to the standby battery. No separate charger, no transfer board. Power drops, the supply hands the load to the battery on its own and puts the charge back when the utility comes home.
"Filtered and electronically regulated" is not sales language on a door. Readers and controller boards are fussy about dirty power, and ripple shows up as ghost faults: a reader that works at ten in the morning and refuses a card at four. I have chased that ghost on jobs where the problem was never the panel.
How to pick a power supply for a maglock door, and the mistake I see most
Here is the one that costs people a return trip. The Altronix ALTV248UL 8 output power supply costs less than the LPS3C24X, gives you eight fused outputs instead of one pair of terminals, and is already on the shelf because the camera guys buy it by the case. Every part of that says "buy this one instead."
Do not. The ALTV248UL is 24VAC, built for cameras: 24VAC or 28VAC output, 3.5 amp at 24VAC or 3 amp at 28VAC, eight fuse-protected outputs with 3.5 amp fuses, surge suppression, an ON/OFF switch, and a UL2044 listing for commercial CCTV equipment. Altronix lists it for cameras, heaters, and video accessories, which is what it is good at.
A DC maglock will not run on it. Neither will a DC strike, controller, or reader. And even if the voltage lined up, the ALTV has no battery charger and no standby switchover, because a camera does not need to keep working when the lights go out. A door does.
What actually happens in a power outage
This is where fail-safe and fail-secure stop being vocabulary words.
A fail-safe maglock drops open
A maglock holds because it is energized. Kill the power and the magnet lets go and the door swings. That is not a defect, that is the design, and it is why a maglock is allowed on an egress door at all. It is also why the AHJ wants to see how you wired the release. The fire alarm interface has to drop that magnet when the alarm calls for it, and the battery cannot hold the door shut through it. Backup here keeps the reader, controller, and door monitoring alive through a blink in the utility. It must never become the reason a door stayed locked during an alarm. Walk that wiring with your AHJ before you close the ceiling.
A fail-secure strike stays locked, which is its own problem
People hear "stays locked" and assume no battery needed. Wrong door. The strike holds when power dies, but everything that makes it a badge-in door dies with it. Reader dark, controller dark, REX and door contact no longer reporting, so the audit trail has a hole in it during exactly the hours you would want one. Staff stand outside waving a credential at a dead reader until somebody finds a key.
Add up the door before you pick the supply
Sizing is arithmetic, and it is the part I will not do over the phone without model numbers. Pull the spec sheet for everything that draws off that supply and total the continuous current: lock, reader, controller board, request-to-exit or motion sensor, keypad, door monitoring, any sounder. A maglock draws the whole time the door is locked, which is nearly all day. A strike draws in bursts, but the panel feeding it never stops. Total it, then leave real headroom so you are not sitting at the edge of the rating on a hot day in a closed closet.
Compare that total against the 2.5 amp continuous rating, and treat the .5 amp maximum charge current as its own budget. If you are still choosing the lock itself, our writeup on the Securitron M680 maglock for a door you cannot mortise covers that side. Once you know the lock, call 877-365-5625 with the model and the door count and we will check the math with you.
Where a door timer and a distribution module fit
Neither is required for a working door. Both solve a real problem when you have it.
The Altronix DL1 door control timer gives the door a timed unlock instead of one that lasts as long as somebody leans on the button. It runs on 12 to 24 volt AC or DC, takes an isolated 3V to 24V trigger, momentary or maintained, and gives a dry relay output, one form "C" contact rated 2 amp, adjustable from 1 second to 1 minute. It also has a 12VDC regulated beeper output, the piece people forget they wanted until a door needs to make noise while it is held open.
The Altronix MOM5 multi-output power distribution module breaks one supply out to multiple device runs, so you are not stacking four sets of conductors on one pair of terminals and hoping the screw holds. Call us on the configuration before you order it.
Common questions
Will the Altronix ALTV248UL power a maglock?
No. It is a 24VAC or 28VAC camera supply, UL listed for commercial CCTV equipment, and a DC maglock will not run on AC. It also has no battery charger and no standby switchover, so it cannot hold a door up in an outage. Use the 24VDC LPS3C24X for locks.
Does the LPS3C24X come with the backup batteries?
The charger and the battery space are built in and the enclosure fits up to two 12VDC batteries, but plan on ordering the sealed lead acid or gel batteries with it. Call 877-365-5625 and we will confirm what ships in the box.
What size power supply do I need for my access-controlled door?
Total the continuous current draw of every device on that door from its own spec sheet, then leave headroom above that total. We will not size it off a guess, so call 877-365-5625 with the lock model and how many doors you are feeding.
Do I need the DL1 timer or the MOM5 module?
No, neither is required. The DL1 earns its keep when you want a timed release or a beeper output, the MOM5 when one supply feeds several devices.
Lock Depot stocks the LPS3C24X, the ALTV248UL, the DL1, and the MOM5, with the rest of the line on our Altronix hub. Call 877-365-5625 with three things and we will pick the supply: the lock model, everything else on that door that draws power, and how many doors are on the run.