Thermal relay function:
The role of thermal relay is the motor overload automatically cut off the power supply, thermal relay structure is two pieces of expansion coefficient of different metal sheet composition, the current is too large when the expansion coefficient of the first expansion, play a role in cutting off the power. Thermal relay after manual reset and automatic reset.
Fuse function:
When the circuit fails or abnormal, accompanied by rising current, and the rising current may damage some important devices in the circuit or expensive devices, it is possible to burn the circuit or even cause a fire. If the circuit is correctly placed in the fuse, then the fuse will rise in the current to a certain height and a certain time, their own fuse cut off the current, which play a protective circuit safe operation
??If the circuit breaker is installed in the circuit breaker, the thermal relay needs to be used in conjunction with the AC contactor. If the contact on the thermal relay is broken, the fuse is usually used for the control circuit.
From the fact that the circuit breaker is a switch, it and other common switch of the main points are: 1. Applicable voltage level 2. Arc medium and way, there are vacuum, less oil, oil and sulfur hexafluoride, etc. 3 Excellent arc suppression capability and good effect.
In general, the circuit breaker itself does not exist lubrication problems, the need for lubrication is often its operating mechanism
Thermal overload relay function:
1. Under normal circumstances, turn on and off the high voltage circuit in the no-load and load current.
2. In the event of system failure with the protection device and automatic device to match, quickly cut off the fault current, to prevent the accident to expand, so as to ensure the safe operation of the system.
