BEST LSEM303 Electrified Morti...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$2,374.29
PRECISION Precision Hardware Inc (PHI) Electrified Latchbolt Monitor Switch, 03 Function Mortise Body, LSEM303

BEST LSEM303 Electrified Mortise Lock with Latchbolt Monitor Switch

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Model: LSEM303 FS 626 RHR
$2,374.29
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$2,374.29
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BEST LSEM303 Electrified Mortise Lock with Latchbolt Monitor Switch

Professional Electric Lock/Unlock Solution with Comprehensive Monitoring

The BEST LSEM303 electrified mortise lock provides electric lock/unlock functionality with integrated switches to monitor both outside trim status (locked or unlocked) and latchbolt position. This handed precision electric mortise lock operates with 24VDC power and features SPDT switch configuration rated to 2 Amps for reliable monitoring and control in commercial applications.

Professional Features & Benefits

  • Dual Monitoring Capability: Integrated switches monitor both outside trim status and latchbolt position for comprehensive access control feedback.
  • Electric Lock/Unlock Operation: Precision electric control with 24VDC operation for reliable remote access management.
  • Heavy-Duty Switch Rating: SPDT switches rated to 2 Amps at 24VDC for dependable monitoring signal transmission to control systems.
  • Handed Configuration: Precision hardware designed for specific door handing requirements ensuring proper fit and operation.
  • Commercial-Grade Construction: Built for demanding commercial applications where reliable electric mortise lock operation is essential.
  • Fail-Safe/Fail-Secure Options: Configurable operation modes allow adaptation to specific security requirements and code compliance needs.

Technical Specifications

  • Commercial/Residential: Commercial
  • Department: Door Hardware
  • Fail-Safe/Fail-Secure: Yes
  • Lock Type: Electric Mortise
  • Product Category: Mechanical Locks
  • Product Group: Mechanical Locks
  • Product Subgroup: Mortise Locks and Trim
  • Product Type: Mortise Locks
  • Series: LSEM303
  • Subcategory: Electric Mortise

Installation & Operation

  1. Verify electrical requirements match available power supply. Confirm 24VDC voltage and current capacity before proceeding.
  2. Disconnect power supply before beginning installation. Follow all applicable electrical codes and safety procedures.
  3. Mount the unit in the specified location ensuring adequate clearance for wiring access, ventilation, and future service requirements.
  4. Route and connect wiring according to manufacturer wiring diagrams. Use appropriate wire gauge and connectors for the application.
  5. Configure operational settings including fail-safe/fail-secure options per application requirements.
  6. Restore power and test all functions including normal operation, monitoring switch functions, and integration with connected systems.
  7. Complete final inspection and document settings. Refer to manufacturer documentation for complete wiring diagrams, programming instructions, and troubleshooting.

Professional Applications

  • Commercial Building Security Systems
  • Healthcare Facility Access Control
  • Educational Institution Safety Systems
  • Government and Municipal Buildings
  • Industrial Facility Monitoring
  • Multi-Tenant Commercial Properties
  • Emergency Access Control Systems

Why Choose BEST Quality?

BEST electrified mortise locks deliver professional-grade reliability with precision electric operation and comprehensive monitoring capabilities. The LSEM303 series provides dependable 24VDC operation with 2 Amp rated monitoring switches for demanding commercial applications. Engineered for commercial environments where reliable electric access control and status monitoring are essential for security and operational efficiency.

Manufacturer Resources

Precision 2000 Series Catalog

Product Specs

Series:
LSEM303
Product Group:
Mechanical Locks
Product Subgroup:
Mortise Locks and Trim
Product Type:
Mortise Locks
Subcategory:
Electric Mortise
Commercial/Residential:
Commercial
Lock Type:
Electric Mortise
Fail-safe / Fail-secure:
Yes
Product Category:
Mechanical Locks
Department:
Door Hardware

BEST LSEM303 FS 626 RHR – Frequently Asked Questions

1) What is the difference between fail-safe and fail-secure on the BEST LSEM303 electrified mortise lock, and which should I order?
The LSEM303 is built one way or the other, so you pick it at order time, not in the field. Fail-safe unlocks the outside trim when power drops, which is what you want on stair re-entry and egress paths tied into the fire alarm. Fail-secure keeps the outside trim locked on power loss, which is the normal choice for storerooms, IT rooms, and tenant suites where you never want the door free on an outage. Both are offered on the electric lock option.
2) What voltage and switch rating does the BEST LSEM303 electrified mortise lock need?
24VDC operation. The monitoring switches are SPDT rated to 2 Amps at 24VDC, so the power supply and the contacts feeding your access control panel both need to suit that. Size the supply for 24VDC before you pull wire, since there is no multi-voltage option stated for this lock.
3) Do I have to specify handing when ordering the BEST LSEM303 mortise lock?
Yes, and it is not field reversible. The LSEM303 is built as Left Hand Reverse or Right Hand Reverse only. Reverse bevel means the door swings out from the secured side, which is the usual condition on stairwell and exterior openings. Stand outside the door, note which side the hinges are on and which way it swings, and order to match, because the wrong hand is a lock you cannot use.
4) Does the BEST LSEM303 work on a fire rated door?
There is a fire rated version of the latchbolt monitor switch, so specify that option when the opening is a rated assembly. The standard switch build is for non-rated openings. This is a separate selection from fail-safe versus fail-secure, and on a rated stair door you will usually be pairing the fire rated switch with fail-safe trim tied to the alarm.
5) What exactly does the LSEM303 monitor, and do I still need a separate door position switch?
Two things are monitored inside the lock body: outside trim status, so the head end knows whether the lever is locked or unlocked, and latchbolt position, so you know the bolt has actually thrown. That covers the lock, not the door. If you need to know the leaf itself is closed, that is a door position switch in the frame, which is a separate device from this lock.
6) What is the closest equivalent to the BEST LSEM303 electrified mortise lock from another manufacturer?
The closest match is the Schlage 03A electric lock/unlock outside lever mortise lock, keyed outside, with request to exit (RX) and 12/24VDC operation, for 1-3/4 inch doors. Like the LSEM303, it is an electrically controlled mortise body with status monitoring and electric control of the outside trim, and the LSEM303 runs on 24VDC as well. The difference in monitoring is worth checking against your panel: the LSEM303 carries switches for both outside trim status and latchbolt position, while the Schlage part is specified with request-to-exit monitoring.
7) I need an electrified mortise lock that can be set to fail-safe or fail-secure in the field instead of ordering it one way. What should I use?
Look at the Command Access ML190 series motorized mortise lock, which is field selectable between EL and EU operation and runs on 24VDC in a heavy-duty storeroom function. The BEST LSEM303 uses the same 24VDC supply but is ordered as a specific configuration: fail-safe or fail-secure is chosen at the time of order, along with left hand reverse or right hand reverse handing. If your spec may change after the doors are hung, the field-selectable ML190 removes that decision from the purchase order.
8) Our opening has no access control panel or wiring. What mortise lock gives us keypad control instead of the BEST LSEM303?
The LSEM303 is a hardwired 24VDC device that expects a control system to lock, unlock and receive the monitor switch signals. For a door with no wiring, standalone electronic mortise locks carry the credential on board: the Alarm Lock DL3500CR Trilogy is a Grade 1 classroom-function electronic mortise lock with 300 user codes for doors 1-5/8 to 1-7/8 inch, and the Schlage CO-100 standalone electronic mortise lock is a Grade 1 heavy-duty privacy-function unit with a keypad reader for 1-3/4 inch doors. Neither reports latchbolt position back to a panel the way the LSEM303 does.
9) Should I use an electrified mortise lock like the LSEM303 or a standalone electronic lock with a keypad?
Different jobs. The LSEM303 is a wired lock controlled from a panel, with 24VDC power and monitor switches reporting back, so it belongs on openings already tied into an access control head end. If there is no panel and no wire to the door, a standalone unit makes more sense: the Alarm Lock DL3500CR Trilogy is a Grade 1 classroom-function keypad mortise lock, and the TownSteel FME-2000 Series is a Grade 1 classroom mortise lockset with RFID. Those run on their own batteries and credentials but will not give a panel real-time latchbolt and trim status.
10) What other wired electric mortise locks could I use instead of the BEST LSEM303?
Two close alternatives from other brands. The Command Access ML190 Series is a heavy-duty motorized mortise lock with field selectable electric latch retraction or electric unlock and 24VDC power, which is useful when you do not want to commit to fail-safe or fail-secure at order time. The Schlage 03A electric lock/unlock mortise lock is heavy duty, keyed outside, with request-to-exit monitoring, 12 or 24VDC, for 1-3/4 inch doors. Pick the Schlage if your spec calls for RX rather than latchbolt monitoring.
11) Can I wire the LSEM303 to unlock a stairwell door on fire alarm?
That is the fail-safe build. Order fail-safe and the outside trim releases when the 24VDC supply drops, so dropping power on alarm frees the outside lever for re-entry. Pair it with the fire rated latchbolt monitor switch option on a rated stair door. Run the release through your fire alarm relay, not through the lock, since the lock has no onboard alarm interface.
12) We only need door position and latch status reported, not electric locking. Is the BEST LSEM303 the right part?
The LSEM303 does both: it is an electric mortise lock that locks and unlocks the outside trim on 24VDC and monitors both trim status and latchbolt position. If the opening does not need remote lock and unlock, a mechanical mortise lock plus separate monitoring is the simpler path. For example the Cal-Royal NM8080 is a heavy-duty Grade 1 storeroom mortise lockset for 1-3/4 inch doors with an interchangeable core option, and the Accentra 8805FL is a Grade 1 storeroom mortise lock in the 8800 series. Neither carries electrical control or switches.
13) Is a wireless mortise lock like the Schlage ENGAGE LEMD a substitute for the BEST LSEM303?
They solve different problems. The Schlage Electronics LEMD-GRW is a Grade 1 ENGAGE series wireless mortise lock with a 125kHz proximity reader, mobile-enabled deadbolt with LED and Greenwich trim, right hand, with a 3 hour fire rating; its credential reading and communication happen at the lock. The BEST LSEM303 has no reader and no wireless radio. It is a 24VDC electric mortise body whose lock and unlock commands come from your access control system and whose SPDT switches, rated 2 Amps, report trim and latchbolt status back to that system. Choose the LSEM303 when a panel and reader already exist at the door.
14) What finishes does the BEST LSEM303 electrified mortise lock come in?
Thirteen finishes, so matching existing openings in a building is usually straightforward: 605 bright brass, 606 satin brass, 611 bright bronze, 612 satin bronze, 613 oil-rubbed satin bronze, 618 bright nickel, 619 satin nickel, 622 matte black, 625 bright chrome, 626 satin chrome, 629 bright stainless, 630 satin stainless, and 690 statuary dark bronze. For commercial corridors 626 and 630 are the common standards.
15) Is the BEST LSEM303 suitable for a healthcare or school building, or is it a residential lock?
Commercial only. It is an electric mortise lock body built for institutional use, and the applications it is written for are healthcare access control, schools, government buildings, industrial monitoring, and multi-tenant commercial. For a home or light-duty interior door, a mortise lock body like the Baldwin 6310 entrance/storeroom is the residential-scale answer instead.
16) We need a residential-style mortise entry lock, not an electrified one. What replaces the BEST LSEM303 on that kind of door?
The LSEM303 is a commercial electric mortise lock and is not intended for that use. For a non-electrified entry opening, the Baldwin 6301 is an entry/apartment mortise lock body with a 2-1/2 inch backset for doors 1-3/4 inch and over, offered knob by knob or, as the 6301LS, lever by lever. If the function needs to be entrance/storeroom instead, the Baldwin 6310 uses the same 2-1/2 inch backset and covers doors 1-3/8 inch and over.
17) Can I use a Sargent 4874 mortise deadbolt where a BEST LSEM303 was specified?
No. The Sargent 4874 is a double cylinder mortise deadbolt with a 2-3/4 inch backset in the 4870 series, so it has no latchbolt and no way to report latch status. The LSEM303 is built around a latchbolt with a monitor switch on it plus a switch reporting whether the outside trim is locked or unlocked, all on 24VDC. If the drawing calls for latchbolt monitoring, a deadbolt will not satisfy it.
How fast can I get the BEST LSEM303 FS 626 RHR delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the BEST LSEM303 FS 626 RHR come with a warranty?
Absolutely. The BEST LSEM303 FS 626 RHR is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the BEST LSEM303 FS 626 RHR?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
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