TH-N12 Thermal Overload Relay

In the field of industrial power distribution and automation control, there are a large number of small and medium-sized motors, and their protection requirements require both precision and reliability, as well as ease of integration and maintenance. The SPX factory's hig quality and CE-certified TH-N12 Thermal Overload Relay is a standardized protection module designed to meet this widespread demand. It does not pursue extreme wide range, but provides highly mature and consistent protection performance within an optimized current range. Whether integrated into new motor starters or used for maintenance and replacement of existing systems, TH-N12 provides users with a worry free, reliable, and easy to manage protection solution with its standardized interface and clear adjustment scale.

Feature

The central adjustment knob has a clear current value scale, allowing users to visually and accurately set according to the rated current of the motor. The operation is intuitive, reducing guessing and errors during the debugging process.
The product design features a trip indicator window (usually a prominent color change) and a manual reset button, making the device status clear at a glance for quick fault diagnosis and system recovery.
SPX high quality TH-N12 Thermal Overload Relay is based on the classic bimetallic strip heating and bending principle, providing overload protection that matches the thermal characteristics of the motor. The built-in differential guide plate mechanism ensures the ability to accelerate tripping response to phase failure and severe three-phase imbalance faults.
Usually designed for direct plug-in installation with small AC contactors of the same series or specified models, TH-N12 Thermal Overload Relay forms a compact and reliable electromagnetic starter, saving installation space and wiring time.
High quality models will include ambient temperature compensation to mitigate the impact of ambient temperature changes on the operating characteristics of the bimetallic strip, ensuring the stability of TH-N12 Thermal Overload Relay protection over a wider temperature range.
The shell can provide basic dust and accidental touch protection for internal precision mechanisms, and is suitable for installation in various control cabinets.

Main application scenarios

TH-N12 is suitable for small and medium power applications that require reliable protection and limited space:
Motor protection for packaging machines, small conveyors, mixers, fans, and other equipment.
Single machine control of automatic doors, ventilation equipment, water pumps, etc.
As a standard protective accessory for the execution unit (contactor) at the output end of PLC or controller.
TH-N12 Thermal Overload Relay, as a widely used universal model, is commonly used to replace damaged thermal relays of the same type in old systems.

The STH-N12 thermal relay is suitable for S-C10/12 AC Contactor

Frame(A)	STH-N18(TH-N18)		STH-N25(TH-N25)		STH-N50(TH-N50)
Suitabie AC contactor	S-C10/12		S-C21/25		S-C50/95
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	15A	12~18
	0.35A	0.28~0.42	1.7A	1.4~2.0	19A	16~22
	0.5A	0.4~0.6	2.1A	1.7~2.5	22A	18~26
	0.7A	0.55~0.85	2.5A	2~3	29A	24~34
	0.9A	0.7~1.1	3.6A	2.8~4.4	35A	30~40
	1.3A	1~1.6	5A	4~6	42A	34~50
	1.7A	1.4~2.0	6.6A	5.2~8	54A	43~65
	2.1A	1.7~2.5	9A	7~11	67A	54~80
	2.5A	2~3	11A	9~13	82A	65~93
	3.6A	2.8~4.4	15A	12~18	95A	85~105
	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-N20		63	51	79	4.5
	TH-N60		89	57	83.5	4.5