KRDM424 - KRDM Series

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Littelfuse Delay on Make Relays
The KRDM Series is a compact time delay relay measuring only 2 in. (50.8 mm) square. Its solid-state timing circuit provides excellent repeat accuracy and stability. Encapsulation protects against shock, vibration, and humidity. The KRDM Series is a cost effective approach for OEM applications that require small size, isolation, reliability, and long life.


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

Property (Mouseover for details) Value
Input Voltage (V) 120VAC
Input Tolerance (%) -20% - 10%
Input AC Line Frequency (Hz) 50/60Hz
Output Type Isolated relay contacts
Output Form SPDT
Output Load Rating (VA) 10A resistive @ 125VAC; 5A resistive @ 230VAC and 28VDC; 1/4hp @ 125VAC; 1/4hp @ 125VAC @ 40oC
Time Delay Range 1 - 100m onboard adjustable
Time Delay Tolerance (%) ±5%
Recycle Time (ms) ≤150ms
Repeat Accuracy (%) ±0.5% or 20ms whichever is greater
Setpoint vs Ambient Temperature and Operating Voltage (%) ≤ ±5%
Switching Voltage Maximum (V) 250VAC
Insulation Resistance ≥100 MΩ
Isolation Voltage (V) ≥1500V RMS input to output
Circuitry Encapsulated
Life Mechanical - 1 x 107; Electrical - 1 x 105
Power Consumption ≤2VA
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 -20° to 60°C (-4°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 1.21 in. (50.8 x 50.8 x 30.7mm)
Weight (lbs/g) ≅2.6oz (74g)
Sample capable No