Temperature monitoring relay

Ideal to prevent heater overheating. Self-latching output to contribute to safe equipment operation.

  • Set the temperature with ultra-simple rotary switches
  • Digitally set the temperature to between 0 and 999°C in 1°C increments (K8DT-TH1__), or between 0 and 1,800°C in 10°C increments (K8DT-TH2__)
  • Connect a thermocouple or platinum resistance thermometer
  • Width of 17.5 mm to reduce space required in panels
  • Push-in plus Technology that reduce wiring work
  • UL listed for easy shipping to North America
  • Double-insertion holes for crossover wiring (all terminals)
  • Models added with transistor outputs for superior contact reliability
Specifications & ordering info

Ordering information

Power supply voltage

Input types

Setting units (setting range)

Output types

Order code


Thermocouple or platinum resistance thermometer

Setting unit: 1°C or 1°F
(0 to 999°C/°F)

Relay: SPDT contact output


Transistor: Open collector


100-240 VAC

Relay: SPDT contact output


Transistor: Open collector




Setting unit: 10°C/°F

Relay: SPDT contact output


Transistor: Open collector


100-240 VAC

Relay: SPDT contact output


Transistor: Open collector



Front Cover (Order separately)


Order code







Power supply voltage

K8DT-TH__D: 24 VAC 50/60 Hz or 24 VDC

K8DT-TH__A: 100 to 240 VAC 50/60 Hz

Allowable voltage range

85% to 110% of power supply voltage

Power consumption

24 VAC or 24 VDC: 2.1 VA max. or 1.2 W max.

100 to 240 VAC: 3.1 VA max.

Sensor inputs

Thermocouple: K, J, T, E;
Platinum-resistance thermometer: Pt100, Pt1000

Thermocouple: K, J, T, E, B, R, S, PL II

Setting method

Set of three rotary DIP switches


Power (PWR): Green, Alarm (ALM): Red

Output form

Relay: SPDT contact output

Transistor: Open collector

Output relay ratings

Resistive load

5 A at 250 VAC
5 A at 30 VDC

Inductive load

1 A at 250 VAC
0.2 A at 48 VDC

Minimum load

5 VDC, 10 mA (reference values)

Mechanical life

10 million operations min.

Electrical life

5 A at 250 VAC or 30 VDC: 50,000 operations
3 A at 250 VAC/30 VDC: 100,000 operations

Transistor output ratings

Contact form

SPST-NO (Open collector)

Rated voltage

24 VDC (maximum voltage: 26.4 VDC)

Maximum current

50 mA DC

Ambient operating temperature

−20 to 60°C (with no condensation or icing)

Storage temperature

−25 to 65°C (with no condensation or icing)

Case material

PC, UL 94 V-0


Approx. 100 g

Size in mm (H × W × D)


Measurement accuracy

±1% of the setting range or ±4 °C, whichever is larger.

±1% of the setting range (±1%FS).

Hysteresis width


Sampling cycle

100 ms

Applicable standards

Approved standards

EN 61010-1

Installation environment: Overvoltage category II, pollution level 2


EN 61326-11

Safety standards

UL 61010-1 (Listing), Korean Radio Waves Act (Act 10564)

Degree of protection

Terminals: IP20

1. Industrial Electromagnetic Environment (EN/IEC 61326-1, Table 2)

1. Industrial Electromagnetic Environment (EN/IEC 61326-1, Table 2)

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