Thermal Overload Relay TH-T25 18A

In the world of motor protection, universal adjustability means flexibility, but it also brings the complexity of debugging and the risk of inconsistent parameters. The China SPX Thermal Overload Relay TH-T25 18A goes in the opposite direction. It is not a widely adjustable tool, but a "safety ID card" precisely cast for a rated current of 18A motor. At the factory, the final calibration is completed with its core protection parameter -18A set current, ensuring that each product can provide the best matching protection for motors of that specific power level out of the box. It represents an efficient engineering philosophy that pursues standardization, consistency, and ease of use.

Advantage:

The product has been deeply calibrated around 18A in the manufacturing process, and the thermal characteristics of the bimetallic strip and the mechanical matching of the release mechanism have reached their optimum at this point. Users do not need to make on-site adjustments, fundamentally eliminating premature or delayed protection actions caused by inaccurate manual calibration.
In the manufacturing of complete equipment or batch projects, the use of Thermal Overload Relay TH-T25 18A in stock can make the protection characteristics of all motors of the same power highly consistent, improving the standardization and reliability of the overall system.
The 18A setting current accurately corresponds to the mainstream three-phase motor power range of 7.5kW to 9kW under 380V voltage, making it an ideal partner for many fans, water pumps, and medium-sized mechanical drive motors.
The thermal capacity and heat dissipation model of the Thermal Overload Relay TH-T25 18A thermal element is optimized for the heating characteristics of motors of this current level, which can more realistically simulate the temperature rise process of motor windings under overload, frequent start stop and other working conditions.
Engineers and installers do not need to consult curve charts or use screwdrivers to adjust, they can directly install wiring, greatly saving debugging time and reducing human errors.

Typical application scenarios

Core protection for 7.5kW-9kW circulating water pumps and feedwater booster pumps.
Overload protection for small air compressors, drive belt motors, and mixing mixers.
Power protection unit for medium-sized fan coil units and fresh air unit fans.
The equipment manufacturer uses the Thermal Overload Relay TH-T25 18A as a standardized, debugging free protective component on one of their fixed power models.

The STH-T25 thermal relay is suitable for S-M20/25 AC Contactor

Frame(A)	STH-T18(TH-T18)		STH-T25(TH-T25)				STH-T50(TH-T50)
Suitabie AC contactor	S-M10/12		S-M20/25				S-M35/50
Aux contact structure	Manual or Auto retum
Adjust range selcet(A)	Select(A)	Adjust range(A)	Select(A)		Adjust range(A)		Select(A)	Adjust range(A)
	0.24A	0.2~0.32	1.3A		1~1.6		29	24~34
	0.35A	0.28~0.42	1.7A		1.4~2.0		35	30~40
	0.5A	0.4~0.6	2.1A		1.7~2.5		42	34~50
	0.7A	0.55~0.85	2.5A		2~3
	0.9A	0.7~1.1	3.6A		2.8~4.4
	1.3A	1~1.6	5A		4~6
	1.7A	1.4~2.0	6.6A		5.2~8
	2.1A	1.7~2.5	9A		7~11
	2.5A	2~3	11A		9~13
	3.6A	2.8~4.4	15A		12~18
	5A	4~6	19A		16~22
	6.6A	5.2~8	22A		18~26
	9A	7~11	29A		24~34
	11A	9~13	35A		30~40
Aux contact structure	1a1b(1NO+1NC)
Outline and installation dimension
	Type		L	W	H	φD
	TH-T25		63	51	81	4.5