FCT18-S Series

Flashing Time Relay
with Independently Adjustable T1 & T2

Industrial-grade symmetrical/asymmetrical flasher with digital setting, ultra-wide voltage range, and flexible start mode selection via control signal.

Wide-voltage 12–240V AC/DC 0.1s–100 days time range 0% setting deviation 0.2% repeat accuracy DIN rail mount 18mm slim design 1×SPDT / 2×SPDT 16A @ 250V AC Start ON/OFF selectable IP40 Front
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FCT18-S Flashing Time Relay
🎯 0% Setting Deviation Digital button configuration eliminates the 5–10% deviation typical of potentiometer-based timers.
🔄 0.2% Repeat Accuracy Matches top international brands for consistent, reliable timing cycle after cycle.
🔒 Anti-Misoperation Lock Long-press required for reconfiguration — prevents accidental parameter changes in the field.
🛡️ Enhanced Anti-EMI Design Reinforced circuit ensures stable operation even in complex electromagnetic environments.
⚡ 12–240V Wide Supply Voltage AC/DC universal — one relay covers virtually all common control voltages worldwide.
⏱️ 0.1s–100d Ultra-Wide Time Range T1 and T2 independently adjustable from 0.1 seconds up to 100 days.

📋 Models & Ordering

Model Supply Voltage Output Contact Control Terminal Start Mode Datasheet
FCT18-S1W 12–240V AC/DC 1 × SPDT S (Control) S open: Start ON / S–A1: Start OFF 📄 Download PDF
FCT18-S2W 12–240V AC/DC 2 × SPDT S (Control) S open: Start ON / S–A1: Start OFF 📄 Download PDF

💡 Control Signal S: When S is open (not connected), the output starts with ON state. When S is connected to A1, the output starts with OFF state, allowing flexible integration into different control schemes.

⚙️ Technical Specifications

🔌 Input

Input TerminalA1 – A2
Supply Voltage12–240V AC/DC
Power ConsumptionAC 3.5VA / DC 2.0W
Voltage Tolerance-15% ~ +10%

🎛️ Time Circuit

FunctionFlashing (symmetrical / asymmetrical)
Time Range T1, T20.1s – 100 days (each independently)
Time SettingButton (digital)
Time Deviation0% – Digital Setting
Repeat Accuracy0.2%
Temperature Coefficient0.01%/°C (at 20°C)

🔌 Output

Contact (S1W)1 × SPDT
Contact (S2W)2 × SPDT
Rated Current16A @ 250V AC
Mechanical Life1×10⁷ operations
Electrical Life1×10⁵ operations

📐 Physical & Environmental

Dimensions18 × 90 × 64 mm
MountingDIN rail EN 60715
Protection DegreeIP40 (front) / IP10 (terminals)
Operating Temp.-20°C ~ +55°C
Storage Temp.-30°C ~ +70°C

📜 Standards & Certifications

ComplianceGB/T 14048.5, IEC 60947-5-1, EN 6812-1
Contact ConfigurationSPDT: 11(COM)-12(NC)-14(NO)
2nd pole: 21(COM)-22(NC)-24(NO)
Pollution Degree2
Max. Cable SizeAWG 13–20 / 0.4 N·m

📈 Function Diagram – Flashing Operation & Start Mode

FCT18-S Flashing Timer Function Diagram

• After power-on, a repetitive cycle consisting of two independently adjustable timing periods T1 and T2 starts.
• Each timing period corresponds to a different state of the output R (ON/OFF). This cycle is repeated indefinitely until the power supply is removed.
• Start Mode Selection via Terminal S:
    – When control signal S is not applied (open), the cycle starts with R ON (T1 ON, then T2 OFF).
    – When control signal S is applied (connected to A1), the cycle starts with R OFF (T1 OFF, then T2 ON).
• Adjust T1 and T2 to create symmetrical or asymmetrical flashing patterns as required.

🎬 See it in Action

🔧 Wiring & Terminal Layout

Terminal Identification

A1 — L / + (Supply) A2 — N / - (Supply) S — Control (Start Mode) 11 — COM 12 — NC 14 — NO 21 — COM (2nd pole) 22 — NC (2nd pole) 24 — NO (2nd pole)
⚠️ Safety Note: Keep the power supply disconnected during the entire installation process. Carefully check the wiring diagram and follow it correctly. Adhere to the specified voltage and current limits for each connection terminal.

Start ON: Leave terminal S open (no connection). Output starts in ON state (relay energized).
Start OFF: Connect S to A1. Output starts in OFF state (relay de-energized).

FCT18-S Wiring and Terminal Layout Diagram

🛠️ Parameter Setting Guide

  1. Enter Parameter Setting Mode: Press and hold the button until the LED starts flashing. This indicates you have entered the configuration mode.
  2. Adjust T1 & T2: Set the desired time range and fine time for both T1 and T2 independently using the button. The scale markings on the front panel guide your setting.
    💡 Note: When the green LED is ON during time range setting, add +5% to the value indicated on the scale for accurate timing.
  3. Confirm New Parameters: After adjusting to your desired values, press and hold the button until the LED stops flashing. The new parameters are now stored.
  4. Make Parameters Effective: After confirming parameters, you must power off and restart the device to activate the new settings.

🏭 Typical Applications

💡 Warning Lights
Flashing beacon control for safety and status indication
🚨 Alarm Systems
Intermittent audible/visual alarm activation
🔄 Cyclic Pump Control
Alternating operation of pumps or compressors
🌬️ Ventilation Cycling
Intermittent fan operation for humidity and temperature management
🏗️ Sequence Control
Repeating on-off cycles for conveyor or feeder systems
📡 Signal Simulation
Generating periodic test signals for PLC inputs

🔗 Related Products

Explore other time relays in the FCT18 series:

FCT18-M — Multifunction Relay FCT18-ST — Star/Delta Relay FCT18-S — Flashing Relay (Current Page) FCT18-CR — Bistable Relay FCT18-B — Off-Delay Relay FCT18-A — On-Delay Relay

❓ Frequently Asked Questions

🔹 What is the difference between FCT18-S1W and FCT18-S2W?
The only difference is the number of output contacts. S1W provides 1 × SPDT contact, while S2W provides 2 × SPDT contacts. Both share identical time ranges, control logic, and start mode selection.
🔹 How does the control signal S determine the start state?
When S is open (no connection), the flashing cycle starts with the output ON (T1 ON period). When S is connected to A1, the cycle starts with the output OFF (T1 OFF period). This allows you to choose whether the output is initially energized or de-energized upon power-up.
🔹 Can T1 and T2 be set to different values?
Yes. T1 and T2 are fully independent and can be set anywhere from 0.1 seconds to 100 days. This lets you create symmetrical flashing (T1 = T2) or asymmetrical patterns (T1 ≠ T2) as required.
🔹 What is the mechanical life of the relay?
The relay has an exceptional mechanical life of 1×10⁷ operations, ensuring long-term reliability even in high-frequency flashing applications. The electrical life is 1×10⁵ operations at rated load.
🔹 Can this relay operate on both AC and DC supply?
Yes. The FCT18-S series accepts 12–240V AC or DC on terminals A1–A2, making it universal for global control panels.
🔹 How do I set T1 and T2 precisely?
Enter parameter setting mode by long-pressing the button until the LED flashes. Adjust T1 and T2 using the button. When the green LED is on during range setting, add 5% to the scale reading for accuracy. Confirm by long-pressing until LED stops flashing, then power-cycle to activate.

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