Discussion on Several Major Faults of Building Intercom Hosts

- Dec 10, 2018-

The building intercom system is a device used in high-rise residential buildings, inside and outside apartment buildings, inter-family information transmission, anti-theft door control and alarms for residents to report to the building duty room in an emergency. The system is mainly composed of a host, an extension, a UPS power supply, an electric lock and a door closer. According to the type, it can be divided into direct-press type, digital type, digital type household pass, direct-press type video intercom, digital video intercom, digital type household video intercom and so on.


The host computer is the control core part of the building intercom system. The transmission signal of each extension and the electric lock control signal are controlled by the host computer. Its circuit board is shock-damped and installed, and it has strong anti-vibration and anti-moisture resistance. With night lighting placement, the appearance is beautiful and generous. So in daily life, what should we do when the building intercom host encounters a fault? Below, let us discuss and analyze several major types of fault problems.


Symptom: The host cannot implement password unlocking.


1. Check if the input password is correct.


2, the operation is not correct: please read the instructions carefully, see if the password setting method is wrong, or the password is not successful;


3. Some building intercom system unlocking lines are connected to the system power supply. If the host displays “OPEN”: the main unit is normal, please check if the electric lock connection is correct, whether the electric lock power supply is short-circuited or other lines. Short circuit


4. If the voltage between the lines connecting the electric lock has been lowered, but the electric lock is not open, the electric lock needs to be replaced. (The electric lock is also a key accessory in the building intercom system. Please choose a quality product to ensure the system is stable and the use is better. );


5, check the door machine: When unlocking, the main part of the door will have a falling pulse, the normal voltage is 12V (some of the second-generation system products mainly detect the door host 7 feet or 8 feet);


6, everything is normal, please consider the quality of the host, try a unit of the same model, function unit;


Subtotal: The general building video intercom system, the password unlocking is not normal, the main reason is caused by the first and second articles; but the second generation of building intercom system, the third, fourth, and fifth cases also have consider.


Symptom: The indoor extension cannot be unlocked when the host can be unlocked normally.


1. The whole part of the machine can't be unlocked: check the main line of the unit system to see if the line has wrong connection, short circuit, intermediate breakage, and then check whether the unit has signal output. Finally, check the floor platform in turn to see if the floor platform is burned or damaged. The floor platforms of most building intercom systems are connected in series;


2. Some indoor extensions cannot be unlocked: check the extension line of the extension to see if the line has wrong connection, short circuit, and intermediate breakage, and then check whether the floor platform has signal output;


3. If the line and floor platform are normal, consider the extension damage, find a replacement of the same model and function extension. Special reminder: If the indoor extension comes with a decoding function, please pay attention to re-encoding when replacing the extension. The actual floor number is better;


4. Method prompt: When detecting the unit host, floor platform and line fault, first use the universal meter to detect whether they have any signal, and minimize the problem. The method of detecting one by one is better than the product of replacing the same model and function;


5, the method prompts: some products signal is normal, but due to the use of the microcontroller chip program, the output signal is all garbled, when the floor platform, extension, host and other products using the microcontroller chip is not normal, It is better to replace the product with the same function and model.


Symptom: The management machine cannot unlock the lock when the host can be unlocked normally.


1. Wire connection error: Check whether the signal line in the networking line is wired correctly. Check whether the wiring of the network converter is normal. Some manufacturers' network bus is directly connected to the unit host, and special inspection is needed.


2, the use of a network converter (or called a network switcher, functions such as routers in the computer network system), if the monitoring function is normal, the management machine and the users in the unit are used normally, mainly considering the switching problem of the network converter Please replace the product test of the same model and function;


3. Line problem: Please check all the lines from the previous building intercom equipment to the unit system to see if there is any breakage, loose joints, short circuit, water immersion and so on.


Symptom: The host cannot call the management machine


1. Host failure: When calling the management machine, use the universal meter to check the output port of the host to see if there is any signal output; please replace the same model and function host test;


2, network converter (switcher) failure: check the wiring of the network converter to see if there is a mistake; when calling the management machine, use the universal meter to detect whether there is signal output to the management port; use the universal meter to detect the network converter by Whether the host input port has a signal input; finally, replace the same model, function network converter test.


Symptom: The host is busy after being powered on.


1. Short circuit: Please do not test again with the main line; consider short circuit of the main line of the system, please check if there is a short circuit in the main line;


2. The floor platform of a certain floor is faulty, leading to short circuit of the system: the floor platform test is broken one layer, and the floor platform test in use is replaced by the alternate floor platform until the cause is detected.


Building intercom system other attention issues


1. Anti-seismic wiring problem: Most building intercom uses terminal or screw connection. Shockproof is also a key. In practice, many intercom mainframes are installed on the movable door leaf, which frequently vibrates with the opening and closing of the door. This kind of problem generally occurs in the contact failure caused by vibration; the second is that the line is not protected by the sheath at the joint of the door frame and the door leaf. When the door leaf is opened, the line is pinched off or severely worn, resulting in system disconnection. Or short circuit; no matter where the intercom mainframe is installed, the anti-shock and wiring must be handled well. It is recommended to install the intercom mainframe on the very open door or in the wall.


2. Unlocking line problem: Most building intercom unlocking lines (to electric control lock lines) are connected from the intercom host to the electric control lock. This type of wiring has many advantages, is firm and can prevent damage and unlock the signal. However, some building intercom unlocking lines are another kind of wiring, that is, connecting the three-core cable from the intercom mainframe to the system power supply, and then connecting the two core wires from the power supply to the electric control lock, and the general building Intercom power can't be installed on the door (mostly concealed on the wall near the door, etc.), this kind of unlocking problem may appear in three aspects: intercom host, power supply, unlocking line, according to experience, fault Mainly concentrated on the power supply and unlocking line. In case of such wiring, please check the unlocking line first, then consider replacing the power supply test, and finally consider the intercom host.