THD7421A - THD2 Series

Series: THD2 Questions? Contact Littelfuse Support
Littlefuse Interval Relays
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The THD2 Series combines accurate timing circuitry with high power solid-state switching. It can switch motors, lamps, and heaters directly without a contactor. You can reduce labor, component cost, and increase reliability with these small, easy-to-use THD2 Series timers.


Operation (Interval)
Upon application of input voltage, the time delay begins. The output energizes during the time delay. At the end of the time delay, the output de-energizes and remains de-energized until input voltage is removed.
Reset: Removing input voltage resets the time delay and the output.

Property (Mouseover for details) Value
Input Voltage (V) 120VAC
Input Tolerance (%) ±20%
Input AC Line Frequency (Hz) 50/60Hz
Output Type Solid state
Output Form NO closed during timing
Output Load Rating (VA) 6A steady state 60A inrush
Minimum Output Load Current (A) 100mA
Output Voltage Drop (V) Effective drop: ≤3V
Time Delay Type Digital integrated circuitry
Time Delay Range 1 - 100s externally adjustable
Time Delay Tolerance (%) ≤±10%
Recycle Time (ms) After timing: ≤150ms; During timing: ≤350ms
Repeat Accuracy (%) ±0.5% or 20ms whichever is greater
Setpoint vs Ambient Temperature and Operating Voltage (%) ≤ ±2%
Insulation Resistance ≥100 MΩ
Dielectric Breakdown ≥2000V RMS terminals to mounting surface
Circuitry Encapsulated
Termination Type 0.25 in. (6.35mm) male quick connect terminals
Mounting Method Surface mount with one #10 (M5 x 0.8) screw
Operating Temperature -40° to 60°C (-40°F to 140°F)
Storage Temperature (F/C) -40° to 85°C (-40°F to 185°F)
Humidity 95% relative non-condensing
Dimensions 2.00 x 2.00 x 1.51 in. (50.8 x 50.8 x 38.4mm)
Weight (lbs/g) ≅3.9oz (111g)
Sample capable No