How to Choose an Electric Latch

How to choose an electric latch

Electric latch, electric forehead plate or electric forehead?

With "c" or without "c"? We do not intend to redefine concepts or designations... In Portugal we ask for permission to call it  electric latch with "c". If you continue reading you will realize what we are talking about. 


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


ELECTRIC LATCH

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




Very useful whenever we want to open an overlapping lock, but not so much when we want to control the mechanical latch of a built-in lock. Then come the electric latches embedded in the door frame that receive and hold the mechanical latch of the lock. We will deal with the selection of this type of electric latch, also forgetting for now the forehead plate of it, which can also have two or three different sizes.  

How to choose - Power supply 12 V or 24 V?

Most models run at 12 V DC (direct current) 
But some can 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              

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

But many still run at 12 V AC (alternating current). These latches are older and are usually attached to video intercom systems, which run on alternating current.

How to choose - AC or DC?


To know 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 of the following:

SE1     SE2MIO     5U0X10 5E0Z10         SE246


How to choose - NO or NC operation?

Electric latches can work in two different ways: 

by cut or by issue.


NO – Normally Open 

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

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

- Disadvantages: Permanent energy consumption.

For the NO – Normally Open latch you should select: 

SE3           5U4X10         SE309         2087JPCOP



 NC – Normally Closed 

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

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

- Disadvantages: In case of lack of current there is no control over the latch.

For the NC – Normally Closed latch you should select: 

SE1   SE2MIO   5U0X10 5E0Z10 SE246 9X0P10         YS-134   YS-136   (NC)-S   2085EJD   2085EJE   2087EJPOOP

How to choose - State Sign?

With this option we can know at any time what the state of the door is - to know if the door is open or closed, transferring to a control panel the signal sent by the latch. This function is important for reasons of security of people and goods

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

SE246 SE309       YS-134     YS-136       (NC)-S

How to choose - Opening Memory?

When we have an electric latch opened, it accomplishes the mission by opening; however, it remains open until the door is opened and re-closed.

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 freed from the latch. 

The only model that has this type of memory is the following:  

SE2MIO

How to choose - Preload?

The electric latch has a latch that holds the mechanical latch of the lock 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, due to the resistance it finds 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 ordered to open, if one or more people find themselves forcing the door open, it will not open... unless the latch used has a special feature that allows it to open even at a pressure load of 400 Nm.

The only model that has this type of memory is the following:  

5E0Z10

How to choose - Glass Door?

A special latch with a U-shaped lash allows it to fit into a glass door keeping it secure and can be seen in:

TWDES400

How to choose - Waterproof?

Much of this electrical equipment is installed in exterior doors subject to rainwater or washing.

Water can irreparably affect circuits, coils, or metal elements.

A preventive solution involves the installation of armored latches and protected from elements.

With IP54 grade protection: 

7X0P40L     TWDES400  

How to choose - Fireproof?

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

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

TW-5F0

Certificate according to UNE EN 1634-1


How to choose - Armored Door?

Armored door locks usually have security locks, consisting of round rods and a mechanical latch. In these cases, if it is intended to use the lock electronically when only hit the latch while it is not closed with a 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 the:

9X0P10 R

We hope this information was helpful.

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

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

Click on the Model to learn more or clarify your doubts here