About Normally Closed and Normally Open

NC means Normally Closed: When the magnet together, the circuit is conductive (light on); when the magnet separates, the circuit is not conductive (light off).

Wired Door & Window Alarm Contacts
Door and window contacts are important for any security system. Wired contacts are easy to use with any hardwired security panel.

They can also interface with wireless security systems if a wired to wireless converter is used. Purchase your wired door and window contacts from the Alarm Grid website.

Door and window contacts are some of the most essential sensors used with a security setup. These devices let the system know when a door or window has been opened. Since most break-ins occur through a door or window, these sensors are very important for letting you know about any potential intruders.

You can program your door and window contacts to perform a predetermined response whenever they are activated. These responses can range from requiring a system disarm to immediately sending a distress signal to the central station.

The majority of door and window contacts operate in a very similar manner. These sensors typically include a sensor and a magnet. The sensor is generally installed on or inside the frame of the door or window, and the magnet is installed on or inside the door or window itself. The magnet should be placed within about half an inch of the sensor to the prevent any false alarms from occurring.

When the door or window is opened, the magnet will pull away and separate from the sensor. This will cause a reed switch inside the sensor to activate. When this happens, the sensor will transmit a signal to the panel to let it know of the situation. From there, the programmed response will occur.

Hardwired door and window contacts are usually more difficult to install than wireless contacts. This is because a wire will need to be run from the sensor to the security system. That said, there are some advantages to using wired contacts.

One consideration is that wired contacts will never require any battery replacements while they are in use. Wireless contacts will usually need a battery replacement every three to five years. This makes wired contacts ideal for users who never want to worry about replacing the batteries on their sensors. Additionally, wired contacts are often less expensive than wireless contacts. Please note that a wired to wireless converter is needed to use wired contacts with a wireless alarm panel.

Wired door and window contacts are generally split into two categories. These are surface-mount contacts and recessed contacts. The difference between the two is that surface-mount contacts are placed on the outside of the door or window, while recessed contacts are installed inside the door or window. In order to install a recessed two holes will need to be drilled.

One hole, in the door or window frame, will house the magnet. The other hole, in the actual door or window, will house the sensor. The drilling of holes makes installing recessed sensors slightly more difficult than installing surface-mount sensors. However, the advantage is that recessed sensors will not be visible on the outside of the door or window.

Alarm Grid offers many great wired door and window contacts. The selection can seem a little overwhelming to new customers. If you need any help choosing a door and window contact, then our support team is happy to help you choose the perfect device. We are available both over the phone or online through chat.

Magnetic Contacts

Magnetic Contacts is a door and window sensor that functions using an internal reed switch in conjunction with a magnet. This is the most common way for a door and window sensor to operate. These devices are known for being particularly easy to use and enroll with security systems.

Like the name implies, a door and window sensor is used to monitor a door or a window and let an alarm system know when it has been opened. These devices are sometimes referred to as “magnetic contacts” because of the way that they operate.

While not every door and window sensor functions in the same manner, the majority of these devices operate using the same principles.

The typical door and window sensor consists of a sensor with an internal reed switch and a separate magnet. The sensor is usually installed on the door or window frame, and the magnet is installed on the moving portion of the door or window.

For best results, the magnet should be placed within about a half-inch of the sensor. When the door or window is opened, the magnet will separate from the sensor.

Once this happens, the sensor’s internal reed switch will activate. In the case of a wireless zone, this will tell the sensor to send an alert to the alarm system to let it know that the door or window has been opened. In the event of a wired zone, this process will actually open a wired circuit which indicates to the system the door or window has been opened.

The system will then perform a predetermined action based on the programming settings for the sensor. So as long the sensor remains in contact with its magnet, the device won’t send an alert to the alarm system.

Both wired and wireless door and window contacts are available for security systems. Both types generally operate using the same aforementioned principles. Remember, a wireless door and window contact will need to communicate at a wireless frequency that is compatible with the alarm system being used.