1. Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of the SINOTIMER TM919A-2 LCD Digital Programmable Timer Switch. This device is designed for automatic control of electrical appliances based on programmed time schedules, offering daily and weekly programming options.
2. Product Features
- Weekly 7-day programmable digital time switch.
- Multiple voltage options (5V, 12V, 24V, 110V, 220V, 85-265V). This specific model is 220V.
- Detachable battery design for backup power.
- 35mm DIN rail mounting for easy installation.
- LCD display for clear time and program viewing.
- 16 ON/OFF programs per day or week.
- Manual override function.
- High capacity 16A switching contact.
3. Safety Information
WARNING: Risk of electric shock. Installation should only be performed by a qualified electrician or competent person.
- Ensure power is disconnected before installation or maintenance.
- Do not exceed the maximum load capacity of 16A.
- Verify correct voltage supply for the specific model (220V for TM919A-2).
- Keep the device away from moisture and extreme temperatures.
4. Product Overview and Components
The SINOTIMER TM919A-2 features an LCD display, control buttons, and wiring terminals for power input and load control.

Figure 4.1: Front view of the SINOTIMER TM919A-2 Digital Timer Switch, showing the LCD display, control buttons (P, D+, H+, M+, RESET, MANUAL), and wiring terminals.

Figure 4.2: The timer switch with its transparent protective cover opened, revealing the control buttons for programming and manual operation.
Control Buttons:
- P (Program): Enters program setting mode.
- D+ (Day): Adjusts day of the week or program day.
- H+ (Hour): Adjusts hour or program hour.
- M+ (Minute): Adjusts minute or program minute.
- RESET: Resets all settings to factory defaults.
- MANUAL: Toggles output ON/AUTO/OFF.
5. Setup and Installation
5.1 Wiring Diagram
Refer to the wiring diagram on the side of the device and the illustration below for correct connection. Ensure all connections are secure.

Figure 5.1: Side view of the timer switch displaying the wiring diagram. Terminals 1 and 2 are for power input (L and N). Terminals 3, 4, and 5 are for the relay output (Common, Normally Open, Normally Closed).
- Terminals 1 & 2 (L, N): Connect to the main power supply (220V AC for this model).
- Terminal 3 (NO - Normally Open): Connects to the load when the timer is ON.
- Terminal 4 (COM - Common): Connects to one side of the load and the power supply.
- Terminal 5 (NC - Normally Closed): Connects to the load when the timer is OFF (less common for typical applications).
5.2 Initial Power-up and Reset
Upon first power-up or after a long period without power, the LCD display may be blank. The internal battery provides backup for settings. If the display is unresponsive or shows garbled characters, press the RESET button using a pointed object (e.g., a pen tip). This will clear all settings and restore the timer to its default state.
5.3 Setting Current Time and Day
- Press the P button once. The display will show the current time setting.
- Press D+ to set the current day of the week.
- Press H+ to set the current hour.
- Press M+ to set the current minute.
- Press the P button again to exit time setting mode and return to normal operation.
6. Operating Instructions
6.1 Programming ON/OFF Cycles
The timer supports up to 16 ON/OFF programs. Each program consists of an ON time and an OFF time.
- Press the P button repeatedly until "1 ON" appears on the display. This is the first ON program.
- Press D+ to select the day(s) for this program. Options include individual days, weekdays, weekends, or all 7 days.
- Press H+ to set the desired hour for the "ON" event.
- Press M+ to set the desired minute for the "ON" event.
- Press P again. "1 OFF" will appear. This is the first OFF program.
- Repeat steps 2-4 to set the day(s), hour, and minute for the "OFF" event.
- Continue pressing P to cycle through "2 ON", "2 OFF", up to "16 ON", "16 OFF". If you do not need all 16 programs, simply press P until the display returns to the current time.
- To save and exit programming mode, press the P button until the current time is displayed.
6.2 Manual Override
The MANUAL button allows you to override the programmed settings temporarily or permanently.
- Press MANUAL once: Toggles between ON/AUTO/OFF modes.
- ON: The output is continuously ON, ignoring programs.
- OFF: The output is continuously OFF, ignoring programs.
- AUTO: The timer operates according to the programmed ON/OFF cycles. This is the standard operating mode.
7. Maintenance
7.1 Battery Replacement
The timer includes a detachable CR2032 lithium battery to maintain time and program settings during power outages. If the display becomes dim or resets frequently, the battery may need replacement.

Figure 7.1: The timer switch shown with its battery compartment open and a CR2032 lithium battery, indicating the detachable battery design.
- Disconnect power to the timer before attempting battery replacement.
- Locate the battery compartment, typically on the side or back of the unit.
- Carefully remove the old CR2032 battery.
- Insert a new CR2032 battery, ensuring correct polarity (+ side up).
- Close the battery compartment.
- Reconnect power and reset the current time and day if necessary.
8. Troubleshooting
- Display is blank:
- Check power supply connections (Terminals 1 & 2).
- Ensure the internal battery is charged or replaced if old.
- Press the RESET button.
- Programs are not running:
- Ensure the timer is in AUTO mode (check the display for "AUTO"). Press MANUAL to cycle modes.
- Verify that the current time and day are set correctly.
- Check that the ON/OFF programs are correctly entered and enabled for the desired days.
- Confirm wiring to the load (Terminals 3, 4, 5) is correct.
- Timer resets unexpectedly:
- The internal battery may be low or depleted. Replace the CR2032 battery.
- Ensure stable power supply to the unit.
9. Specifications
| Feature | Specification |
|---|---|
| Model | TM919A-2 |
| Power Supply | 220V AC (as per model) |
| Power Consumption | 4.5 VA (MAX) |
| Temperature Range | -20°C to +50°C |
| Display | LCD |
| Switching Contact | 1 changeover switch |
| Programs | 16 ON/OFF per day or week |
| Hysteresis | 2 sec/day (at 25°C) |
| Capacity | 16A |
| Timer Range | 1 minute to 168 hours |
| Minimum Interval | 1 minute |
| Black-out Memory | 60 days (with internal battery) |
| Item Weight | 0.15 kg (5.3 ounces) |
| Mounting | 35mm DIN Rail |
| Screen Size | 1.2 Inches |

Figure 9.1: Dimensional drawing of the SINOTIMER TM919A-2, showing measurements in centimeters for height, width, and depth.
10. Warranty and Support
Specific warranty information for the SINOTIMER TM919A-2 is not provided in the product details. For warranty claims or technical support, please contact your retailer or the manufacturer directly. Keep your purchase receipt as proof of purchase.





