3-phase thermal overload relay has functions of overcurrent and phase-failure protection for AC motors. It is used to provide overload protection open-phase protection and protection against unbalanced current for motors and it can also avoid heating in electrical equipment. Current setting range 0.1A~6A, current rating 25A, working voltage 220V~690V. Cheap thermal relay, can used with 9A contactor and 2A gG fuse breaker.
Specification
Model |
ATO-JR28-25 |
Current Setting Range (A) |
0.1-0.16 |
0.16-0.25 |
0.4-0.63 |
0.63-1 |
1-1.6 |
1.6-2.5 |
2.5-4 |
4-6 |
Matching Fuse Breaker (A) |
gG |
2 |
2 |
2 |
4 |
4 |
6 |
10 |
16 |
aM |
0.25 |
0.5 |
1 |
2 |
2 |
4 |
6 |
8 |
Trip Class |
9A |
Frame Current (A) |
25A |
Rated Working Voltage (V) |
3-phase 220V~690V |
Rated Insulation Voltage (V) |
690V |
Number of Contacts |
1NO + 1NC |
Phase Failure Protection Function |
yes |
Automatic & Manual Reset |
yes |
Temperature Compensation |
yes |
Tripping Indicator |
yes |
Test Pushbutton |
yes |
Mounting Mode |
Plug-in, independent |
AC-15 220V Current Rating (A) |
2.73 |
AC-15 220V Current Rating (A) |
1.58 |
DC-13 220V Current Rating (A) |
0.2 |
Details
Thermal Overload Relay Applications
- Thermal overload relays are often used in circuit protection, overload, phase failure, overtime start and locked-rotor for AC motors.
- Thermal overload relay has functions of phase failure protection, temperature compensation, adjustable setting current, automatic or manual reset, operation indicator, NC and NO auxiliary contacts separate insulation.
- The thermal overload relay has small installation area and various mounting methods. It has test button and stop button, which is convenient for checking the flexibility of operation.
- The protective cover of thermal overload relay can protect fingers from electric shock. The locking device can prevent misoperation.
- Thermal overload relay comes with remote operation, complete functions and excellent quality.
0.1~6 Amp Thermal Overload Relay Dimension Diagram (Unit: mm)
Cross Section Area of Conductor
Main Circuit |
Single core or standard wire |
1~4 mm2 |
Wiring screw |
M4 |
Auxiliary Circuit |
Single core or standard wire |
0.5~2.5 mm2 |
Wiring screw |
M3.5 |
Tips: What is a 3 phase thermal overload relay?
Thermal overload relay is also called thermal relay, which is a 3 phase overload relay, using the principle of current thermal effect, using electrical thermosensitive bimetal as sensitive components. The electrical thermosensitive bimetal sheet is heated and rolled by two alloys with a large difference in linear expansion coefficient. When heated, the bimetallic sheet bends from the high expansion layer (active layer) to the low expansion layer (passive layer). When the current is too large (exceeding the set value), the element will act due to heating. Then, its linked movable-break contact cuts off the power supply of the controlled circuit and the protected equipment.
3-phase thermal overload relays are used for AC motor overload protection, and there are many types. 3-phase thermal overload relay is easy to install and use, has complete functions and low price. Practice has proved that thermal overload relays can reliably protect AC motors, so they have been widely used for a long time.