Adjustable Thermal Relay
  • Adjustable Thermal Relay - 0 Adjustable Thermal Relay - 0
  • Adjustable Thermal Relay - 1 Adjustable Thermal Relay - 1
  • Adjustable Thermal Relay - 2 Adjustable Thermal Relay - 2
  • Adjustable Thermal Relay - 3 Adjustable Thermal Relay - 3
  • Adjustable Thermal Relay - 4 Adjustable Thermal Relay - 4
  • Adjustable Thermal Relay - 5 Adjustable Thermal Relay - 5

Adjustable Thermal Relay

Established in 2005, Zhejiang SPX Electric Appliance Co., Ltd. proudly presents the STH-T series Adjustable Thermal Relay, meticulously crafted for optimal performance. Tailored for AC 50/60Hz systems, this relay is engineered to safeguard general AC motors from overload and phase break issues during long-term or intermittent operations. With a rated operating voltage up to 690V and a current capacity of 630A, it offers versatile protection.

Send Inquiry

Product Description


The SPX advanced STH-T series Adjustable Thermal Relay is designed for the general overload and phase break protection of AC motors, capable of long-term or intermittent operation, with a rated operating voltage of up to 690V and a current capacity of 630A. It is suitable for AC 50/60Hz systems and incorporates features such as phase break protection, temperature compensation, trip indication, and both automatic and manual reset functionalities. Additionally, it can be conveniently integrated with contactors or installed independently.

The STH-T18 thermal relay is suitable for S-M10/20 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


SPX Adjustable Thermal Relays Feature And Application

Environmentally raw material
Flame retardant material, heat-resisting
Long machine life
3C certificate

Hot Tags: Adjustable Thermal Relay, China, Manufacturer, Supplier, Factory, Quality, Customized

Send Inquiry

Please feel free to fill your inquiry in the form below. We will reply you in 24 hours.