FCT18-B Series
Power Off-Delay Relay
Power Off-Delay Relay
with Control Signal
Industrial-grade time relay with digital setting, ultra-wide voltage range, and exceptional accuracy for demanding automation applications requiring delayed opening.
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
NPN / PNP
IP40 Front
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
From sub-second pulses to multi-day delays — all in a single compact unit.
📋 Models & Ordering
| Model | Supply Voltage | Output Contact | Trigger Type | Control Terminal | Datasheet |
|---|---|---|---|---|---|
| FCT18-B1WN | 12–240V AC/DC | 1 × SPDT | NPN | A2 – S | 📄 Download PDF |
| FCT18-B1WP | 12–240V AC/DC | 1 × SPDT | PNP | A1 – S | 📄 Download PDF |
| FCT18-B2WN | 12–240V AC/DC | 2 × SPDT | NPN | A2 – S | 📄 Download PDF |
| FCT18-B2WP | 12–240V AC/DC | 2 × SPDT | PNP | A1 – S | 📄 Download PDF |
💡 Naming convention: W = Wide voltage (12–240V AC/DC), N = NPN trigger, P = PNP trigger, 1 = 1×SPDT, 2 = 2×SPDT. Control signal: NPN type connects S to A2; PNP type connects S to A1.
⚙️ Technical Specifications
🔌 Input
| Input Terminal | A1 – A2 |
| Supply Voltage | 12–240V AC/DC |
| Power Consumption | AC 3.5VA / DC 2.0W |
| Voltage Tolerance | -15% ~ +10% |
🎛️ Control Circuit
| Control Terminals | A1–S (PNP) / A2–S (NPN) |
| Control Pulse Length | min. 25ms / max. unlimited |
| Function | Off-Delay |
| Time Range | 0.1s – 100 days |
⏱️ Time Circuit
| Time Setting | Button (digital) |
| Time Deviation | 0% – Digital Setting |
| Repeat Accuracy | 0.2% |
| Temperature Coefficient | 0.01%/°C (at 20°C) |
🔌 Output
| Contact (B1 series) | 1 × SPDT |
| Contact (B2 series) | 2 × SPDT |
| Rated Current | 16A @ 250V AC |
| Mechanical Life | 1×10⁷ operations |
| Electrical Life | 1×10⁵ operations |
📐 Physical & Environmental
| Dimensions | 18 × 90 × 64 mm |
| Mounting | DIN rail EN 60715 |
| Protection Degree | IP40 (front) / IP10 (terminals) |
| Operating Temp. | -20°C ~ +55°C |
| Storage Temp. | -30°C ~ +70°C |
📜 Standards & Certifications
| Compliance | GB/T 14048.5, IEC 60947-5-1, EN 6812-1 |
| Contact Configuration | SPDT: 11(COM)-12(NC)-14(NO) 2nd pole: 21(COM)-22(NC)-24(NO) |
| Pollution Degree | 2 |
| Max. Cable Size | AWG 13–20 / 0.4 N·m |
📈 Function Diagram – Off-Delay Operation
• After power-on, output relay R closes (NO contact makes, NC breaks) and timing period T starts.
• At the end of the timing period T, the output relay R opens.
• Closing of the control signal S makes the output relay R close.
• Opening of S restarts the timing period T.
• After the duration T, the output relay R opens again.
This cycle repeats each time S toggles. Removing supply voltage resets the device.
🎬 See it in Action
🔧 Wiring & Terminal Layout
Terminal Identification
A1 — L / + (Supply)
A2 — N / - (Supply)
S — Control Signal
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.
NPN models (WN): Control signal between S and A2.
PNP models (WP): Control signal between S and A1.
🛠️ Parameter Setting Guide
- Enter Parameter Setting Mode: Press and hold the button until the LED starts flashing. This indicates you have entered the configuration mode.
-
Adjust Time Range & Fine Time: Use the button to set the desired time range (coarse) and fine time adjustment. 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.
- 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.
- Make Parameters Effective: After confirming parameters, you must power off and restart the device to activate the new settings.
🏭 Typical Applications
Industrial Automation
Delayed stop for conveyors, assembly lines after process completion
Delayed stop for conveyors, assembly lines after process completion
Motor Protection
Delayed disconnection to cool down or complete a cycle
Delayed disconnection to cool down or complete a cycle
Lighting Control
Automatic off-delay for staircases, corridors, and parking lots
Automatic off-delay for staircases, corridors, and parking lots
HVAC Systems
Fan off-delay to purge residual heat or maintain circulation
Fan off-delay to purge residual heat or maintain circulation
Power Supply Protection
Off-delay to ensure safe shutdown sequence for sensitive equipment
Off-delay to ensure safe shutdown sequence for sensitive equipment
Emergency Stop Circuits
Controlled delayed power-off for safe machinery shutdown
Controlled delayed power-off for safe machinery shutdown
🔗 Related Products
Explore other time relays in the FCT18 series:
❓ Frequently Asked Questions
🔹 What is an Off-Delay relay and how does the control signal work?
An Off-Delay relay keeps its output closed when powered on and starts the timing cycle. The output opens only when the set time elapses. The control signal S can re-close the output and restart the timing, making it ideal for extending operation after a trigger signal disappears.
🔹 What is the difference between NPN (WN) and PNP (WP) models?
The trigger logic differs: NPN models (WN) require the control signal to connect S to A2 (sinking), while PNP models (WP) require the control signal to connect S to A1 (sourcing). Choose based on your PLC or control system output type.
🔹 Can this relay operate on both AC and DC supply?
Yes. The FCT18-B series accepts 12–240V AC or DC on terminals A1–A2, making it truly universal for global control panel designs.
🔹 How do I set a time value of exactly 30 seconds?
Enter parameter setting mode (long-press until LED flashes), set the coarse time range to the appropriate scale, then use fine time adjustment. Note: when the green LED is on during range setting, add 5% to the scale reading. Confirm by long-pressing until the LED stops flashing, then power-cycle the device.
🔹 What is the minimum control pulse length required?
The control signal pulse must be at least 25 milliseconds to trigger the timing cycle. There is no maximum limit — the signal can remain active indefinitely.
🔹 Is the output contact rated for inductive loads?
The SPDT contacts are rated for 16A @ 250V AC. For inductive loads (motors, solenoids, contactors), proper snubbing or derating is recommended to maximize contact life.
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