1. Introduction
The GEYA GRT8-D True Delay Off Relay is designed for applications requiring a delayed shutdown without a continuous supply voltage. It is particularly useful in scenarios such as emergency lighting, voltage fault management, emergency ventilators, and fire door control systems. This manual provides detailed instructions for the safe and effective use of your GRT8-D relay.
2. Safety Information
WARNING:
- All electrical connections and installation must be performed by qualified electricians in compliance with local and national electrical codes and safety standards.
- Ensure the power supply is disconnected before any installation, wiring, or maintenance work to prevent electric shock.
- Do not operate the device if it appears damaged or has been subjected to excessive moisture.
Disposal of Electrical Waste:
- All electrical waste should be disposed of in compliance with current WEEE (Waste Electrical and Electronic Equipment) regulations. Do not dispose of with household waste.
3. Product Overview and Features
The GRT8-D is a modular time relay designed for DIN rail mounting, offering reliable delay-off functionality. Key features include:
- Function: True Delay OFF without Supply Voltage.
- Delay Range: Adjustable from 0.1 seconds to 10 minutes using a rotary switch and fine-setting potentiometer.
- Energy Storage: Built-in energy storage capacitor provides a maximum delay of 10 minutes even after the main power supply is removed.
- Voltage Range: AC/DC 12-240V, with clamp terminals for secure connections.
- Output: 1 SPDT (Single Pole Double Throw) contact, rated at 16A/AC1.
- Indication: Relay status is clearly indicated by a green LED (Supply) and a red LED (Output).
- Mounting: 1-MODULE, DIN rail mounting for easy integration into electrical panels.
4. Technical Specifications
| Parameter | GRT8-D |
|---|---|
| Function | Delay OFF without supply power |
| Supply terminals | A1-A2 |
| Voltage range | AC/DC 12-240V (50-60Hz) |
| Burden | AC 0.7-3VA / DC 0.5-1.7W |
| Supply voltage tolerance | -15%; +10% |
| Supply indication | green LED |
| Time ranges | 0.1s-10min |
| Time setting | potentiometer |
| Time deviation | 10%-mechanical setting |
| Repeat accuracy | 0.2%-set value stability |
| Minimum power time | 200ms |
| Temperature coefficient | 0.05%/°C |
| Output | 1xSPDT |
| Current rating | 16A/AC1 |
| Switching voltage | 250VAC/24VDC |
| Min. breaking capacity DC | 500mW |
| Output indication | red LED |
| Mechanical life | 1x106 |
| Electrical life (AC1) | 5x104 |
| Reset time | max. 200ms |
| Operating temperature | -20°C to +55°C |
| Storage temperature | -35°C to +75°C |
| Humidity | Up to 95% RH (non-condensing) |
| Mounting/DIN rail | Din rail EN/IEC 60715 |
| Protection degree | IP40 for front panel/IP20 terminals |
| Operating position | any |
| Overvoltage category | II. |
| Pollution degree | 2 |
| Max. cable size (mm²) | solid wire max. 1x2.5 or 2x1.5 / with sleeve max. 1x2.5 (AWG 12) |
| Tightening torque | 0.8Nm |
| Dimensions | 90x18x64mm |
| Weight | 69g |
| Standards | EN 61812-1, IEC60947-5-1 |
5. Installation
The GRT8-D relay is designed for DIN rail mounting. Ensure proper ventilation around the device.
5.1 Wiring Diagram
Connect the relay according to the following wiring diagram. Pay close attention to the terminal markings (A1, A2, 15, 16, 18).
5.2 Wiring Example (with UPS Backup)
For applications requiring a true delay off even in case of voltage failure, the GRT8-D can be integrated with a UPS backup power supply. This setup ensures the load's supply voltage automatically converts to backup power, allowing the delay function to complete.
Note on Wiring Example:
- Terminals 15-18 are Normally Open (NO).
- Terminals 15-16 are Normally Closed (NC).
- With power applied to A1-A2, the 15-16 contact will disconnect, and 15-18 will close after the set delay time.
- No external power supply is needed after power off; the internal capacitor supplies power for a delay time of up to 10 minutes.
6. Time Setting
The GRT8-D features two knobs for setting the delay time:
- Knob 1 (Top): Sets the delay range (1s, 10s, 100s, 10m).
- Knob 2 (Bottom): Adjusts the delay time within the selected range from 10% to 100%.
The total delay time is calculated as: Knob 1 (Range) × Knob 2 (Percentage).
Examples:
- To set for 5 seconds: Set Knob 1 to '10s'. Set Knob 2 to '50%'. Delay time = 10s × 50% = 5s.
- To set for 8 minutes: Set Knob 1 to '10m'. Set Knob 2 to '80%'. Delay time = 10m × 80% = 8m.
Important Note on Time Setting:
The position indicated by the arrow in the picture (Figure 5) is the wrong setting position. The delay range can only be set in four distinct positions: 1s, 10s, 100s, and 10m. Please do not set the rotary switch in the middle of these ranges (e.g., between 1s-10s, 10s-100s, or 100s-10m). If set incorrectly, the red LED will continuously flash.
7. Operation
7.1 Power-On and Initial State
Upon applying power (Un) to terminals A1-A2, the green LED (Supply) will illuminate. The relay requires a minimum power-on time of 200ms to charge its internal energy storage capacitor. Ensure the relay is powered on for more than 200ms for proper function.
7.2 Delay Function
When the supply voltage (Un) is removed, the relay will begin its delay-off sequence. The red LED (Output) indicates the status of the output contact. During the delay period, the output contact will remain in its active state (e.g., 15-18 closed if it was closed before power loss). After the set delay time has elapsed, the output contact will revert to its original state (e.g., 15-18 disconnected).
7.3 LED Indications
- Green LED (Un): Indicates the presence of supply voltage.
- Red LED (R): Indicates the status of the output contact.
7.4 Resetting the Relay
The relay can be reset after 1 second. This means if the power is turned back on within 1 second of being turned off, the relay will reset its timing cycle. If the power is off for more than 1 second, the relay will complete its delay cycle before resetting.
8. Maintenance
- Regularly inspect the terminals for secure connections.
- Keep the device clean and free from dust and debris.
- Ensure the operating temperature remains within the specified range (-20°C to +55°C).
- Avoid exposing the device to excessive humidity or corrosive environments.
9. Troubleshooting
- Red LED continuously flashing: This indicates an incorrect setting of the time range knob. Ensure the knob is set precisely to one of the four marked positions (1s, 10s, 100s, or 10m), not in between.
- Relay not delaying after power loss: Verify that the relay was powered on for at least 200ms to allow the internal capacitor to charge. Check the wiring for correct connections.
- Unexpected contact closure/opening: Due to the working characteristics of the built-in magnetic latching relay, strong vibration during transportation might cause the 15-18 contact to close by mistake. After installation, set the delay to 1 second, then cycle the power on and off. The relay should reset after 1 second (15-16 closed, 15-18 disconnected).
10. User Tips
- For critical applications, always test the delay settings thoroughly before deployment.
- Consider the ambient temperature, as extreme conditions can affect the relay's performance and lifespan.
- When installing, ensure sufficient space for heat dissipation, especially if multiple relays are mounted together.
11. Warranty and Support
For warranty information, technical support, or further inquiries, please refer to the official GEYA website or contact your local distributor. A detailed user manual in PDF format is available for download from the manufacturer's website: GEYA GRT8-D User Manual (PDF).