By Kent · Lock Depot Staff Writer

One night latch, five prefixes

Search the Von Duprin 98 Series for a night latch and you get a wall of part numbers that all end in NL. The letters in front are what you are really buying. 98NL is the plain mechanical device. Put LD, CD, EL or QEL in front and the device talks to an access control system. Order the wrong prefix and you either pay for electronics you cannot wire or end up with a door that cannot do what the spec says.

Every one of these is a Grade 1, ANSI/BHMA A156.3 rim exit device with hex key dogging standard. Every one is a night latch, which means the outside trim locks and unlocks by key and the inside is always free for egress. Every one ships less cylinder. The listings we pulled are satin chrome (US26D) for a 3 foot door, and the catalog lists a 4 foot version of each.

98NL: the mechanical device

The 98NL-US26D-3 has no electronics. It is the answer for a door that needs a key from outside and a bar from inside, and nothing else. The listing describes the handing as field reversible, so one part number covers either swing.

The listing's own pro-tip is the one I would take from this whole article: check the frame for strike compatibility. The 98 uses a standard rim strike, but on hollow metal frames you may need a longer lip strike if the frame rabbet is deeper than standard. It says most callbacks on rim devices are strike alignment, and in my experience that is right.

LD98NL: with a latch detector

The LD98NL-US26D-3 adds a latch detector. Per the part number breakdown on the listing, a switch monitors the position of the latch bolt and reports it to the access control panel. It runs on 24 VDC, and the switch comes factory installed and wired to a pigtail for connection at rough-in.

The listing's use case is a school. The teacher locks and unlocks from outside, and the access panel can verify latch status for a lockdown. One flag before you order: the product title on this listing reads "Less Dogging," while the part number breakdown inside the same listing reads Latch Detector. The breakdown, the 24 VDC rating and the pro-tip all describe a latch detector. If you were hunting for a device with the dogging removed, do not assume this is it. Tell us what you need and we will confirm the part number before it ships.

CD98NL: controlled dismiss

The CD98NL-US26D-3 is the Controlled Dismiss version. The listing says it electrically locks and unlocks the exit device from a remote location, at 24 VDC. That is the feature for a door where someone at a desk or a panel decides whether the bar works.

The listing also states that hex key dogging is standard on the 98 rim devices, so the door can be held retracted during business hours and the bar works as a push and pull. Note that this listing calls for a mortise cylinder, where the others call for a rim cylinder. Confirm the cylinder type with us when you order.

EL98NL: electric latch retraction

The EL98NL-US26D-3 adds Electric Latch Retraction. A card reader, fob or buzzer signal retracts the latch, and the door opens without anyone pushing the bar. It is 24 VDC. The night latch trim on this listing locks automatically when the door closes, key required from outside, always free from inside.

That is the access-control retrofit. If you are working an existing 98 door, our guide to the Von Duprin EL98TP goes through what electric latch retraction does to a panic bar and what it takes to wire it.

QEL-98NL: the quiet one

The QEL-98NL-US26D-3 is the Quiet Electric Latch Retraction version. The listing describes a motor-driven retraction that provides quiet, ADA-compliant remote unlocking, and calls for 24 VDC power. The difference from the EL is in how it moves the latch. The listing says nothing about it being faster or stronger, so the choice is about noise and the building.

A library, a hospital corridor, a lobby where an audible clack at every badge-in is a complaint: that is the QEL door. If the room is loud anyway, the EL does the same job. Our write-up of the Von Duprin QEL on a 9848 covers the same feature on a vertical rod device, and the RX and QEL wiring guide covers the request to exit side.

The quick table

• 98NL: key from outside, bar from inside, no power.
• LD98NL: adds a latch position switch to the panel, 24 VDC. Confirm the part number, see above.
• CD98NL: remote lock and unlock of the bar, 24 VDC.
• EL98NL: electric latch retraction on a signal, 24 VDC.
• QEL-98NL: quiet electric latch retraction, 24 VDC.

Power is the part people forget

Four of the five need a supply. A 24 VDC device on an undersized supply browns out on the first activation and gives you nuisance lockouts that look like a bad device. Size the supply for the load before you order, and our guide to the 990 series trim explains what the night latch trim itself does.

Common questions

What does NL mean on a Von Duprin 98?

Night latch. The outside trim locks and unlocks by key, and the inside is always free.

Do the electric versions need power?

Yes. The LD, CD, EL and QEL listings each call for 24 VDC.

Is the handing field reversible?

The 98NL, LD98NL, CD98NL and QEL-98NL listings say field reversible. The EL98NL listing does not state it, so confirm before you order.

Does the night latch version come with a cylinder?

No. They ship less cylinder; order one to match your keyway.

Which version for a school classroom door?

The listing names the latch detector version as the go-to for schools, so the panel can verify latch status.

The full range is on our Von Duprin page. Tell us the panel, the voltage and the door and we will name the part number.