In factories, using thermal relays to protect large motors can lead to breaks in the main power lines, specifically in the screw connections leading to and from the thermal relays. This can easily cause overheating and potential malfunctions. Using a comprehensive motor protector instead of fuses and thermal relays, because the protector is a through-type device, can reduce the number of breaks in the main power lines, thus reducing overheating and potential malfunctions.
When using a motor protector, attention must be paid to the wiring of the control circuit to ensure the normal operation of the machine. It can replace low-voltage electrical appliances such as circuit breakers, contactors, thermal relays, and fuses.
The installation steps for the motor protector are as follows:
1. Based on the installation location requirements and the needs of the protection functions, rationally select the model of the motor protector and set its various protection action parameters;
2. Install correctly according to the product instruction manual. Connect all terminals correctly according to their intended use. The power supply should be connected before the control circuit, and ensure that the nominal voltage matches the actual voltage.
3. When a current transformer is used with a motor protector, if an ammeter display is required at the equipment site or in the control room, it is best to use a separate current transformer; otherwise, it will affect the current display of the phase with the ammeter.
4. When installing a split-type protector, do not use matching current transformers and display components with different serial numbers together;
5. It can be improved according to user requirements. The 4-20 mA analog output should be matched with the connected device.
6. Proper grounding: When the low-voltage system is a TN-C protection system, the grounding protection line of the equipment on the load side of the protector must be changed to an independent protective grounding according to the TT system. The neutral line must not be grounded repeatedly and must not be used as a protective line.
