ESDR Series - Recycling Timer

Littelfuse Recycle Time Delay Relays
The ESDR Series offers independent time adjustment of both delay periods. Adjustment options include fixed, onboard or external adjust. The ESDR is recommended for air drying, automatic oiling, life testing, chemical metering and automatic duty cycling. This series is designed for general purpose commercial and industrial applications where a small, cost effective, reliable, solid-state timer is required. The factory calibration for fixed time delays is <±5%. The repeat accuracy, under stable conditions, is 0.1% of the selected time delay. This series is designed for input voltages of 12VDC to 230VAC in five ranges. Time delays of 0.1 seconds to 1000 minutes are available in six ranges. The output is rated 1A steady and 10A inrush. The modules are totally solid state and encapsulated to protect the electronic circuitry.


Operation (Recycling - ON Time First)

Upon application of input voltage, the output energizes and the T1, ON time begins. At the end of the ON time, the output de-energizes and the T2, OFF time begins. At the end of the OFF time, the output energizes and the cycle repeats as long as input voltage is applied.
Reset: Removing input voltage resets the output and time delays, and returns the sequence to the first delay.


Operation (Recycling - OFF Time First)

Upon application of input voltage, the T2 OFF time begins. At the end of the OFF time, the output energizes and the T1 ON time begins. At the end of the ON time, the output de-energizes and the cycle repeats as long as input voltage is applied.
Reset: Removing input voltage resets the output and time delays, and returns the sequence to the first delay.

Access specifications, certifications, check availability and order parts below

Catalog #Input
Voltage (V)
Storage Temperature (F/C)Time Delay RangeSample capableCompare
ESDR120A0P12VDC-40° to 85°C (-40°F to 185°F)ON time first: 0.1 - 10s onboard adjustable; OFF: 0.1 - 10s onboard adjustableNo
ESDR120B3P12VDC-40° to 85°C (-40°F to 185°F)ON: 0.1 - 10s onboard adjustable; OFF time first: 0.1 - 10m onboard adjustableNo
ESDR123B4P12VDC-40° to 85°C (-40°F to 185°F)ON: 0.1 - 10m onboard adjustable; OFF time first: 1 - 100m onboard adjustableNo
ESDR125A5P12VDC-40° to 85°C (-40°F to 185°F)ON time first: 10 - 1 000m onboard adjustable; OFF: 10 - 1 000m onboard adjustableNo
ESDR221A224VAC-40° to 85°C (-40°F to 185°F)ON time first: 1 - 100s onboard adjustable; OFF: 10 - 1 000s onboard adjustableNo
ESDR320A0P24VDC-40° to 85°C (-40°F to 185°F)ON time first: 0.1 - 10s onboard adjustable; OFF: 0.1 - 10s onboard adjustableNo
ESDR320A3P24VDC-40° to 85°C (-40°F to 185°F)ON time first: 0.1 - 10s onboard adjustable; OFF: 0.1 - 10m onboard adjustableNo
ESDR420A0120VAC-40° to 85°C (-40°F to 185°F)ON time first: 0.1 - 10s onboard adjustable; OFF: 0.1 - 10s onboard adjustableNo
ESDR420A1120VAC-40° to 85°C (-40°F to 185°F)ON time first: 0.1 - 10s onboard adjustable; OFF: 1 - 100s onboard adjustableNo
ESDR420A4120VAC-40° to 85°C (-40°F to 185°F)ON time first: 0.1 - 10s onboard adjustable; OFF: 1 - 100m onboard adjustableNo
ESDR420B1120VAC-40° to 85°C (-40°F to 185°F)ON: 0.1 - 10s onboard adjustable; OFF time first: 1 - 100s onboard adjustableNo
ESDR420B4120VAC-40° to 85°C (-40°F to 185°F)ON: 0.1 - 10s onboard adjustable; OFF time first: 1 - 100m onboard adjustableNo
ESDR421A1120VAC-40° to 85°C (-40°F to 185°F)ON time first: 1 - 100s onboard adjustable; OFF: 1 - 100s onboard adjustableNo
ESDR421A4120VAC-40° to 85°C (-40°F to 185°F)ON time first: 1 - 100s onboard adjustable; OFF: 1 - 100m onboard adjustableNo
ESDR423A3120VAC-40° to 85°C (-40°F to 185°F)ON time first: 0.1 - 10m onboard adjustable; OFF: 0.1 - 10m onboard adjustableNo
ESDR423A4120VAC-40° to 85°C (-40°F to 185°F)ON time first: 0.1 - 10m onboard adjustable; OFF: 1 - 100m onboard adjustableNo
ESDR424A1120VAC-40° to 85°C (-40°F to 185°F)ON time first: 1 - 100m onboard adjustable; OFF: 1 - 100s onboard adjustableNo
ESDR450A1120VAC-40° to 85°C (-40°F to 185°F)ON time first: 1 - 100m onboard adjustable; OFF: 1 - 100s onboard adjustableNo