Why Choose the ABB CT-ERS.21S ON-Delay Timer?
The ABB CT-ERS.21S is a single-function electronic time relay from the ABB CT-S timer range, designed to provide reliable ON-delay timing for industrial automation and control systems. It provides a straightforward delay-on-make function with two changeover relay outputs for flexible switching applications.
The CT-ERS.21S provides 10 selectable time ranges from 0.05 s to 300 h and operates from a universal 24–240 V AC/DC control supply. The adjustable time delay allows equipment, contactors, signalling circuits and other control devices to be switched after a defined period following energisation.
The timer features 2 c/o (SPDT) relay contacts rated at 250 V / 4 A. Its compact 22.5 mm wide housing uses screw connection technology with double-chamber cage terminals and is designed for DIN rail installation in industrial control panels.
Key Advantages
- Reliable ON-delay electronic time relay for industrial automation.
- Single-function design for straightforward delay-on-make control.
- 10 selectable time ranges from 0.05 s to 300 h.
- Universal 24–240 V AC/DC control supply.
- 2 c/o (SPDT) relay outputs for flexible switching.
- 250 V / 4 A rated relay contacts.
- Compact 22.5 mm wide DIN rail housing.
- Screw connection technology with double-chamber cage terminals.
- Clear front-face adjustment of the selected time range.
- Sealable transparent cover available as an accessory to help prevent unauthorised adjustments.
Key Features
- ABB CT-S timer range.
- ON-delay (delay-on-make) timing function.
- 10 selectable time ranges from 0.05 s to 300 h.
- 24–240 V AC/DC rated control supply.
- 2 c/o (SPDT) contacts.
- 250 V / 4 A rated output contacts.
- 50/60 Hz AC or DC operation.
- Screw connection technology with double-chamber cage connection terminals.
- Front-face screwdriver adjustment for time selection.
- DIN rail mounting for compact control cabinet installation.
- Three LEDs provide operating status indication.
- Sealable transparent cover available as an accessory.
Reliable ON-Delay Timing for Industrial Automation
The ABB CT-ERS.21S provides a dedicated ON-delay function for applications where an output needs to operate after a defined time following energisation. The straightforward single-function design makes it suitable for control circuits where dependable delay-on-make operation is required without the additional complexity of a multifunction timer.
With ten selectable time ranges covering 0.05 s to 300 h, the CT-ERS.21S can accommodate both short machine-control delays and extended process timing requirements. Its two changeover relay outputs provide flexible interfacing with contactors, signalling circuits, motors and other industrial automation equipment.
Typical Applications
- Industrial automation and control panels.
- Motor and contactor control circuits.
- Machine sequencing and timed control.
- Conveyor and production machinery control.
- Delayed switching applications.
- Process automation and equipment sequencing.
- Industrial signalling and alarm circuits.
- Control systems requiring extended time delays.
- Applications requiring universal AC/DC timer operation.
