Securitron MUNL-24, MUNL-12 User Manual

ASSA ABLOY, the global leader
In door opening solutions

MORTISE UNLATCH

®

ELECTRONIC STRIKE

INSTALLATION AND OPERATING INSTRUCTIONS

MODELS MUNL-12 and MUNL-24

Securitron Magnalock Corp. www.securitron.com
Tel [phone] [e-mail]

© Copyright, 2011, all rights reserved PN# 500-18800
Rev. E, 11/11

Securitron Magnalock Corp. www.securitron.com ASSA ABLOY, the global leader

Tel [phone] [e-mail]

in door opening solutions

SECURITRON MODEL MUNL-12, MUNL-24 MORTISE UNLATCH

INSTALLATION AND OPERATING INSTRUCTIONS

1. DESCRIPTION
Securitron’s Mortise UnLatch is a revolutionary new type of electric strike which eliminates the

necessity to perform a routing operation on the door frame for installation. The motor
driven Mortise UnLatch also presents a fully concealed appearance on the door which not

only enhances architectural appeal but improves security over a conventional electric strike as
an intruder is less able to determine the type of security device present on the door. The
Mortise UnLatch functions with all North American mortise locks and includes a latch

status output which reports when the door is in latched (secure) condition or is open.
Product Specifications are: Input Voltages: 12 VDC (MUNL-12), +20%, -10%. 24 VDC

(MUNL-24), +20%, -10%. Current: At rest: 40 mA (either voltage). When operating- 4 Amp
input surge @ 12 VDC; 2 Amp input surge @24 VDC for 1 00 millise conds and 60 0 mA @ 12 V DC
or 300 mA @ 24 VDC during motor movement. Operating Temperature: -10 to 125 F.

FIG 1: MORTISE UNLATCH DIMENSIONS (INCHES)

1.25

1.25
SPRINGLATCH

PLUNGER

DEADLATCH
FINGERS

3.38

3.50

1.88

4.88

RECOMMENDED TOOLS

MEDIUM + SMALL PHILLIPS DRIVER
MEDIUM SLOTTED DRIVER
CHISEL, 5/64 ALLEN WRENCH
WIRE CUTTER/STRIPPER
VOLT/OHM MET ER
CRIMP CONNECTORS
CRIMP PLIERS

2. PHYSICAL INSTALLATION

2.1 SURVEY

The installer must first be sure that the latch is of the mortise type (see the drawing to the
right.) A mortise lock (or latch) includes a square shaped springlatch
and a “pin” called the deadlatch pin or guard bolt which may be
positioned either above or below the springlatch. Most mortise panic

bar latches are also perfectly compatible with the MUNL. Note,
however, that if the mortise lock assembly includes a dead bolt,
the dead bolt will not be operable The most common alternate type
of latch in use in North America is called cylindrical, tubular or
bored. The standard UnLatch (model numbers UNL-12 and UNL-24)

is designed for this alternate type of latch. Securitron does not offer an
UnLatch solution for a rim latch (rim latches are on the surface of the
door rather than being mortised into the middle of the door).

Deadlatch Pin

Springlatch

© Copyright, 2011, all rights reserved PN# 500-18800
Page 1 Rev. E, 11/11

2.2 HOLLOW METAL (STEEL) FRAME MOUNTING

Remove the existing ANSI 4 7/8” strike plate (it will be discarded) and experimentally try to fit
the Mortise UnLatch in the resulting cavity. In some cases the cavity will be large enough to
accommodate the Mortise UnLatch and you will have nothing to do but pull the wires up the
hollow door frame and screw the Mortise UnLatch into place. In other cases you will find a “dust
box” within the frame that will get in the way of the Mortise UnLatch. The dust box must be
cleared away to make room. Generally, a sabre saw, dremel tool or a drill with a fly cutting bit
is the most effective tool to do this. You can also find that the edge of the dry wall panel
interferes with the Mortise UnLatch. Simply chip away some of the dry wall with a screwdriver.
Once you are able to fit the Mortise UnLatch into the frame, vacuum out any concrete dust
and metal shavings (these can work their way into the UnLatch mechanism and cause
problems) and loosely mount it and proceed to Section 2.4, adjusting for latch/deadlatch
location. Note that the face of the Mortise UnLatch is protected by a removable film.
Leave this on during the “pre-mounting” so as to preserve the metal finish against scratching
and to block the possible entry into the mechanism of dust or metal shavings. Remove the film
when you adjust the unit for latch/deadlatch location (Section 2.4).

2.3 WOOD FRAME MOUNTING

For installation in a wood frame use a chisel to create a space for the Mortise UnLatch behind the
existing strike. Remove the strike and place the template (last page of this manual) on the
door (registering it to the strike mounting holes). This will show you the space that must be
chiseled out. As you get close to finishing the chiseling job, experimentally try to fit the body of
the Mortise UnLatch in the cavity. This will avoid chiseling too big a space. A tight fit is
preferred as it helps the solidity of the mounting. Normally, with a wood frame, the wires will
be run inside the wall. Simply drill from the back of the cavity you have created rearward into
the wall space to admit the wires. To mount the Mortise UnLatch to t he wood frame, use the
two #12 x 1” furnished flat head wood screws. Once you are able to fit the Mortise UnLatch in to
the frame, vacuum out any wood dust and metal shavings (these can work their way into
the UnLatch mechanism and cause problems) and loosely mount it and proceed to Section

2.4, adjusting for latch/deadlatch location. Note that the face of the Mortise UnLatch is
protected by a removable film. Leave this on during the “pre-mounting” so as to preserve

the metal finish against scratching and to block the possible entry into the mechan ism of dust or
metal shavings. Remove the film when you adjust the unit for latch/deadlatch location (Section

2.4).

2.4 ADJUSTING FOR LATCH/DEADLATCH LOCATION
One of the remarkable features of the Mortise UnLatch is that it adjusts to suit different

models of North American mortise locks. With conventional electric strikes, the strike

model typically needs to be matched to the lock/latch model and this complicates sourcing the
electric strike. There is one known exception: Sargent model 7800 or 8200 in retrofit
(the lock is already present). The Sargent lock can not normally be accommodated because its
springlatch and deadlatch pin are positioned so close to the bottom of the opening. To employ
the Mortise UnLatch with Sargent, purchase the accessory tab kit, model #STK-1. These
new mounting tabs sufficiently reposition the Mortise UnLatch to make it work with the Sargent
Lock. Note that in new construction, when the door and frame have been specifically
prepared for the Mortise UnLatch and Sargent 7800/8200, the accessory tab kit is not
needed.

Adjustment of the Mortise UnLatch is necessary because different lock manufa cturers vertically
position both the springlatch and deadlatch pin in widely differing locations alon g the lock body.
The Mortise UnLatch accommodates this by allowing positional adjustment of its springlatch
plunger (the component which pushes in the springlatch) and then op erating the deadlatch pin
though moving “deadlatch fingers” which fill the rest of the strike opening.

The adjustment procedure is accomplished in two logical steps. First you must determine th e

position of the springlatch plunger and then perform the adjustment to set that
position.

PN# 500-18800
Page 2 Rev. E, 11/11

2.4.1 EXCEPTIONS:

When working with Corbin Russwin ML2000 and BEST Series 2 Mortise Locks the dead latch
needs to be removed. With both of these locks the dead latch is not retracted by the lever set
when you are exiting the secure area this means that depending on the door gap the dead latch
may hang up on the stainless steel case of the MUNL.

2.4.2 DETERMINING SPRINGLATCH PLUNGER LOCATION
The goal of this determination is to vertically align the Mortise UnLatch’s springlatch

plunger with the lock’s springlatch. The deadlatch pin will then be “ automatically” operated

by the deadlatch fingers regardless of its position on the lock. It’s important, however, to
determine the position in such a way that maximum tolerance is achieved in the event that the
door shifts against the frame.

To begin, loosely mount the Mortise Unlatch and close the door so that you can see the top and
bottom of the lock’s springlatch. Draw lines on the lip of the Mortise UnLatch’s strike which
correspond to the lock’s springlatch position. Next dismount the Mortise UnLatch. The drawn
lines and knowledge of the gap between the springlatch and deadlatch pin are used to determine
the vertical position of the springlatch plunger. When this gap is greater than ¼”, best
reliability is obtained when the springlatch plunger position is centered on the springlatch.
When the gap is smaller than ¼”, however, simply centering the springlatch plunger risks
positioning the deadlatch pin too close to the springlatch plunger so the procedure is to position
the edge of the springlatch plunger midway between the springlatch and deadlatch pin. Figure 2
illustrates these points.

FIG. 2: DETERMINING POSITION OF SPRINGLATCH PLUNGER

SPRINGLATCH

MEASURE GAP
BETWEEN
SPRINGLATCH AND
DEADLATCH PIN

DEADLATCH PIN
(MAY BE ABOVE)

GAP BETWEEN
DOOR AND FRAME

SPRINGLATCH
PLUNGER

GREATER THAN 1/4" GAP

DRAW LINES ON MORTISE
UNLATCH DENOTING TOP
AND BOTTOM OF SPRINGLATCH

CURVED LIP OF
MORTISE UNLATCH

LESS THAN 1/4" GAP

WHEN THE GAP BETWEEN THE SPRINGL ATC H AND DEA DLATCH PI N
IS LESS THAN 1/4", SET THE BO TTOM EDGE OF THE SPRINGLATCH
PLUNGER MIDWAY BETWEEN THE SPRINGLATCH AND DEADLATCH
PIN. (NOTE THAT THE DEADLATCH PIN MAY BE BELOW THE
SPRINGLATCH AS IN THIS EXAMPLE, O R ABOVE IT)

EXAMPLE OF SPRINGLATCH
PLUNGER CENTERED WITH
RESPECT TO SPRINGLATCH
POSITION (SHOWN BY
DRAWN LINES). THE PLUNGER
SHOULD BE CENT ERED WHEN
THE GAP BETWEEN THE
SPRINGLATCH AND DEADLATCH
PIN IS GREATER THAN 1/4"

SPRINGLATCH BOTTOM EDGE (EXAMPLE)
DEADLATCH PIN TOP EDGE (EXAMPLE)

MIDWAY POSITION

2.4.3 ADJUSTING SPRINGLATCH POSITION

Now that you have marked the unit with the correct position for the springlatch plunger, the
actual adjustment must be performed. Figure 3 shows the procedure.

PN# 500-18800
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