KRDI320 - KRDI Series

Series: KRDI Questions? Contact Littelfuse Support
Littlefuse Interval Relays
The KRDI 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 KRDI Series is a cost effective approach for OEM applications that require small size, isolation, reliability, and long life.


Operation (Interval)
Upon application of input voltage, the time delay begins. The output relay 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) 24VDC
Input Tolerance (%) -15% - 20%
Input DC Ripple (%) ≤10%
Output Type Isolated relay contacts
Output Form SPDT
Output Load Rating (VA) 10A resistive @ 125VAC; 5A resistive @ 230VAC and 28VDC; 1/4hp @ 125VAC
Time Delay Range 0.1 - 10s onboard adjustable
Time Delay Tolerance (%) ≤±5%
Reset 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
Polarity DC units are reverse polarity protected
Life Mechanical - 1 x 107; Electrical - 1 x 105
Power Consumption ≤2W
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