How to Choose an Electric Latch

How to choose an electric latch

Electric latch, electric forehead plate or Electric forehead?

With a "c" or no "c"? We do not intend to redefine concepts or designations... In Portugal and the north we ask permission to call it electric latch with "c". If you keep reading, you'll understand what we're talking about.

We just want to make a contribution to facilitate the choice of a building element increasingly used by installers and designers, which has revolutionized by simplicity and functionality the way we close doors.


The electric latch is one of the oldest electric locks and was initially designed for the control of doors in residential buildings. This was fixed to the blade of the active door and actuated by an electric bobine, which pulled the mechanical latch from the oversum lock.

Very useful whenever you want to open an overlapping lock, but not so much when we want to control the mechanical latch of an inlay lock. Then appear the electric lats embedded in the door ring that receive and hold the mechanical latch of the lock. We will take care of the selection of this type of electric latch, forgetting for now the forehead plate of the same, which can also have two or three different sizes.

How to choose - Power 12 V or 24 V?

Most models run at 12 V DC (direct current)
But some may work at 24 V DC due to the existence of a 24 VDC transformer on site.
If this is the case, 24VDC, you should select one of the following:

SE1 SE2MIO 5U0X10 5U4X10 5E0Z10 99NC TOP

Most run at 12 V DC (direct current), as mentioned.

But many still work at 12 V AC (alternating current). These lats are older and are usually added to video-intercom systems, which run the alternating current.

How to choose - AC or DC?

To find out if your latch is AC (alternating current) or DC (direct current), just listen to the noise produced when it is powered.

- AC produces a vibrating sound, like a beetle (trrrr)
- DC produces a fast sound like a click

If your latch is AC you should select one from the following:

SE1 SE2MIO 5U0X10 5E0Z10 99NC TOP 52NF SE246

How to choose - Running NO or NC?

Electric laters can operate in two different ways:

by cutting or by issue.

NO - Normally Open

The latch is normally open. To close you need to be provided with power.

- Advantages: In case of lack of current the door opens (emergency exits);

- Disadvantages: Permanent energy consumption.

For the NO - Normally Open latch you must select:

SE3 5U4X10 SE309 YS-132(NO)-S 2087JPCOP

NC - Normally Closed

The latch is normally closed. To open it you need to be provided with power.

- Advantages: Low energy consumption. It only consumes when it receives opening order;

- Disadvantages : Inthe event of a lack of current, there is no control over the latch.

For NC latch - Normally Closed you should select:

SE1 SE2MIO 5U0X10 5E0Z10 99NC TOP 52NF SE246 9X0P10 7X0P40 YS-134 YS-136(NC)-S 2085EJD 2085EJE 2087EJPOOP

How to choose - Status sign?

With this option we can know at any time what the state of the door - know if the door is open or closed, transferring to a control board the signal sent by the latch. This function is important for the safety of persons and property

If you want to know if the door is open or closed by means of an electrical signal sent by the electric latch you must select:

SE246 SE309 YS-134 YS-132(NO)-S YS-136(NC)-S

How to choose - Opening Memory?

When we have an electric latch opened, it fulfills the mission, opening; however, it remains open until the door is opened and closes again.

This function can be useful when you want to keep the door open until the user arrives.

However, it can constitute a lack of security if the door is not opened in the meantime, being permanently released from the latch.

The only model that has this type of memory is:


How to choose - Preload?

The electric latch has a tab that holds the mechanical lock latch preventing it from opening.

When the two are in charge, the lock latch and the sharing of the electric latch, it may happen that the electric latch does not release the door, as a result of the resistance found in the lock. In some cases, when the electric latch is ordered to open, it is necessary to pull the door before pushing it, to allow pressure relief.

No preload
The latch does not unlock while force is exerted on the door

With preload
The latch unlocks even with force exerted on the door

To understand the importance of this effect, imagine an emergency exit door served by an electric latch:

When you are ordered to open, if one or more people find themselves forcing the door to open, it will not open... unless the latch used has a special feature that allows you to open even with a pressure load of 400 Nm.

The only model that has this type of memory is:


How to choose - Glass Door?

A special latch with a U-shaped eyelash allows you to fit into a glass door while keeping it safe and can be seen in:


How to choose - Waterproof?

Most of this electrical equipment is installed in outdoor doors subject to rainwater or washes.

Water can irreparably affect circuits, bobines or metal elements.

A preventive solution involves the installation of shielded and protected lashes of elements.

With IP54 grade protection:


How to choose - Fireproof?

The constituent elements of a certified fire door cannot limit its functionality in the event of fire, opening and closing normally for movement of fleeing persons, as long as its structure remains functional and the expandable thermos joint does not block its movement.

The installed electrical latch cannot therefore lock the lock with which it interacts. The latch that has these characteristics is:


Certificate according to UNE EN 1634-1

How to choose - Armored Door?

Armored door locks usually have safety locks consisting of round rods and a mechanical latch. In these cases, if you want to use the lock electronically when only hit in the latch while not closed with mechanical key, it is good to be able to count on this functionality using a special electric latch. The latch that has this function is:

9X0P10 R

We hope this information has been helpful.

We add that all the above-mentioned equipment has a door retention force of more than 300 KG, most of which resist tensile forces of more than 500 kg.

To make your choice easier, check out the grill we have prepared for you.

Click on the Template to learn more or clarify your questions here.