Useful information about electric door openers
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How do electric door openers work?
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Additional security techniques for the door
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Versions of the door opener: Working and standby current
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Advantages and disadvantages at a glance
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Typical applications
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Questions and answers
How do electric door openers work?
The automatic NC contact can be conveniently installed in the door floor. If the front door is closed, the E-NC contact is connected to the trap of the door panel. An electromagnetic process is responsible for opening the door if necessary.
The locking plate, which is located in the door frame, is moved electromagnetically over an axis. As a result, the door is released and can be opened from the outside. After the door closes again, a new visitor will need to unlock the door again.
Many NC contacts also enable opening via remote control. This allows you to press a button to release the door. In this case, the remote control makes contact with the door.
Did you know ... The electrical normally closed contact does not look electronic at first glance, as shown in Figure 1. This is why it does not disturb a nostalgic ambience in the old building at all.
Additional security techniques for the door
As soon as the door is closed or falls back into the lock by itself, it is locked as before. There is an additional latch for increased security, which is needed especially at night. This will also be pushed forward to protect the building against burglars at the most.
Another safety and comfort aspect is the connection of the opener with an intercom system and/or video surveillance . You will hear and/or see who requests admission and then decide whether the person is allowed access. This is then done simply via a button.
Versions of the door opener: Working and standby current
Standby power door opener
This version (Figure 3) can also be opened in the event of a power failure, which is why it is suitable for the always open escape doors. They can be recognized by their click noise, which is produced by mechanical unlocking.
Working current door opener
This model unlocks the doors as long as there is contact between the opener and the door. This is indicated by a humming sound, which is likely to be known to many visitors. However, in the event of a power failure, this variant remains closed and is therefore not suitable for escape doors.
Good to know
If there is a lot of public traffic, a so-called daily release is recommended for the door opener, which releases the door for the entire day. This change is achieved by changing a small lever on the door lock. The disadvantage is that controlled access is not possible. Most modern models have the day release when required.
Advantages and disadvantages at a glance
| Advantages: | Disadvantages: |
|---|---|
| · They offer maximum comfort · the door does · have to be opened manually, but unauthorized persons cannot enter it easily · almost all models can be used for both left and right front doors · Door openers offer a high level of security, especially through extras such as fingerprint sensors · Easy installation is possible · usually there are small installation dimensions | · Electric door openers usually require a power source · depending on the model, they do not function in the event of a power failure, and are therefore unsuitable for escape doors · They often only offer maximum protection against burglary with additional latches · In the case of frequent public traffic, a daily release is important as an addition |
Typical applications
Especially in large apartment blocks with multi-family houses E-NC contacts are used, since they save the inhabitants the way to the main door. In addition, they are advantageous in the commercial sector.
In addition, the combination with an intercom system or video camera ensures that the commercial area is fully monitored – a huge security advantage.
Questions and answers
How is the NC contact installed and operated?
The normally closed contact can be fitted to an existing mechanical door lock by aligning it with the existing trap in the door frame. It requires a power source and can be operated both via DC and AC voltage. The difference can be determined by the type of opener: AC voltage-operated door openers buzz, those with DC voltage provide only a clicking sound. A look at the intercom also helps to check how the opener should be fitted.
How is a defective NC contact repaired?
An electric door opener can usually be easily replaced in the event of a defect. You can find the affected component at Conrad. We will be happy to help you find the right spare part. Most products have a voltage that varies between 6 and 12 volts. Modern devices are sometimes also operated with 10 or 24 volts.
Our tip: Look at the door opener housing to determine the correct voltage, or contact our service team.