Electromagnetic Relay Motor Protection Thermal Overload Relay UL Approvals

UKH series thermal overload relays apply to industrial circuit of AC 50Hz or 60Hz, rated voltage to below 660V and rated current . 1A-800A for AC motor overload and open-phase protection during long time or intermittent long time service, which can also protect 3-phase serious imbalance and long starting time of motor or long timer operation, can also be used for corresponding AC contactor for electromagnetic starter.

Specifications:

Characteristics:

1. Be mounted with contactor UKC1-22 directly
4. 1NO+1NC tripping contact
5. Class 10A tripping standard
6. Phase-failure protection type: UKK
7. Sstandard type: UKH
8. Applicable ambient temperature: -5 to 60 degree
9. Manual/automatic reset
10 Desigh of trip free
11. CT cation type .

Construction of Thermal Relay:

The construction of thermal relay is quite simple. As shown in the figure above the bimetallic strip has two metals – metal A and metal B. Metal A has lower coefficient of expansion and metal – B has higher coefficient of expansion. One heating coil is would on the bimetallic strip. When over current flows through the heating coil, it heats up the bimetallic strip.

Due to the heat generated by the coil, both of the metals are expanded. But expansion of metal B is more than expansion of metal A. Due to this dissimilar expansion the bimetallic strip will bend towards metal A as shown in the figure below.

Main benefits:

1. Reliable protection for motors

2. Easy to create starters

3. Optimized match to UKC1 series contactors

4. Single mounting kits and wire reset for remote control available for specific applications.

Working conditions:

1. The installation altitude less than 2000m

2. The surrounding temperature range: from -5°C ~ +40°C

3. In the non-explosive condition. or without adequate erosion and destruction of gas and

dust conductive area .

4. Without rain and snow invade

5. Pollution level 2