HRDI421 - Interval Timer Series

Series: HRDI
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The HRDI Series combines an electromechanical relay output with microcontroller timing circuitry. It offers 12 to 230V operation in five ranges and factory fixed, external, or onboard adjustable time delays with a repeat accuracy of ±0.5%. The output contact rating allows for direct operation of heavy loads, such as compressors, pumps, blower motors, heaters, etc. This series is ideal for OEM applications where cost is a factor.


Operation (Interval)
Upon application of input voltage, the time delay begins. The output relay is energized 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.

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Product Literature

For Technical Questions

Call +1 800-832-3873 or email us at relays@littelfuse.com 

Property (Mouseover for details) Value
Input Voltage (V) 120 V ac
Input Tolerance (%) -20% - 10%
Input AC Line Frequency (Hz) 50/60
Output Type Electromechanical relay
Output Form Non-isolated SPDT
Output Load Rating (VA) General Purpose: SPDT-NO: 125/240 V ac ≅30 A; SPDT-NC ≅15 A; Resistive: SPDT-NO ≅30 A for 125/240 V ac and 20 A for 28 V dc; SPDT-NC ≅15 A for 125/240 V ac and 10 A for 28 V dc; Motor Load: SPDT-NO ≅1 hp for 125 V ac and 2 hp for 240 V ac; SPDT-NC ≅1/4 hp for 125 V ac and 1 hp for 240 V ac
Time Delay Type Microcontroller
Time Delay Range 1 - 100 s onboard knob
Time Delay Tolerance (%) ±5%
Recycle Time (ms) ≤150
Repeat Accuracy (%) ±0.5% or 20 ms whichever is greater
Setpoint vs Ambient Temperature and Operating Voltage (%) ≤±2%
Surge Protection IEEE C62.41-1991 Level A
Insulation Resistance ≥100
Dielectric Breakdown ≥2000V terminals to mounting surface
Circuitry Encapsulated
Life Electrical: 1 x 10⁵ 3 x 104 for 1 hp - 6000 for 1/4 hp 1 hp and 2 hp; Mechanical: 1 x 10⁶
Power Consumption ≤4 VA
Termination Type 0.25 in. (6.35 mm) male quick connect terminals
Mounting Method Surface mount with 1 #10 (M5 x 0.8) screw
Operating Temperature -40° to 60°C (-40° to 140°F)
Storage Temperature (F/C) -40° to 85°C (-40° to 185°F)
Humidity 95% relative : non-condensing
Dimensions 3 H x 2 W in. (76.7 x 51.3 mm)
Weight (lbs/g) 0 Kg
Dimensions 3 H x 2 W in. (76.7 x 51.3 mm)
To request product environmental information, please complete the Product Environmental Information Request Form.