Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of the Intermatic T1906 SPDT 24-Hour Time Switch. Please read all instructions carefully before installation and use to ensure proper function and safety.
Important Safety Information:
- Always disconnect power at the circuit breaker before installing or servicing the time switch.
- Installation should be performed by a qualified electrician in accordance with all local and national electrical codes.
- This device is designed for indoor use within a 3R steel enclosure.
Product Overview
The Intermatic T1906 is a robust 24-hour time switch designed for automatic control of electrical loads. It features a single-pole, double-throw (SPDT) switch and operates on 208-277 Volts. Key features include:
- Up to 96 operations (48 ON/48 OFF) every 24 hours.
- 15-minute minimum ON/OFF intervals.
- Captive trippers for easy setting.
- Suitable for applications requiring daily repetitive scheduling.
Installation
Safety Precautions
- Ensure power is OFF at the main service panel before beginning installation.
- Verify voltage supply matches the time switch rating (208-277V).
- Ground the enclosure properly.
Mounting
- Select a suitable indoor location for the 3R steel enclosure, protected from direct weather and excessive moisture.
- Mount the enclosure securely using appropriate fasteners through the pre-drilled holes.
Wiring
Refer to the wiring diagram provided inside the enclosure cover. The T1906 is an SPDT switch, meaning it has one common terminal and two switched terminals (normally open and normally closed).
- Connect the incoming line voltage to the designated line terminal.
- Connect the load(s) to the appropriate switched terminals (NO or NC) and the neutral/return line.
- Ensure all connections are tight and secure.
- CAUTION: Make sure non-operating trippers (if any) clear the switch lever.
- IMPORTANT: The insulator must be replaced after wiring to prevent shock.

Figure 1: Internal view of the Intermatic T1906 Time Switch. This image displays the 24-hour clock dial with numerous small, gold-colored captive trippers around its circumference. A central silver hand indicates the current time. Below the dial, a translucent plastic insulator covers wiring terminals, with a warning label visible: "CAUTION: MAKE SURE NON-OPERATING TRIPPERS (IF ANY) CLEAR SWITCH LEVER" and "THIS INSULATOR MUST BE REPLACED AFTER WIRING TO PREVENT SHOCK."
Operating Instructions
Setting the Time
- Rotate the dial clockwise only until the current time aligns with the time indicator arrow. The dial is marked with AM and PM hours.
Setting ON/OFF Times
The T1906 uses captive trippers around the dial to set ON and OFF times. Each tripper represents a 15-minute interval.
- To set an ON period, push the trippers outwards for the desired duration.
- To set an OFF period, leave the trippers in their inward position for the desired duration.
- Ensure that the trippers are firmly set in their respective positions (in or out).
- For models with a skipper wheel (if applicable), operations can be omitted on selected days of the week. Refer to the specific instructions for skipper wheel adjustment if your model includes this feature.
Manual Override
The time switch may include a manual override lever. Consult the specific product diagram for its location and operation. This allows for temporary ON/OFF control without affecting the programmed schedule.
Maintenance
- The Intermatic T1906 is designed for minimal maintenance.
- Periodically inspect the enclosure for any signs of damage or corrosion.
- Ensure all wiring connections remain secure.
- Keep the internal components free from dust and debris.
- Do not lubricate any internal parts.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Time switch does not operate. | No power supply; incorrect wiring; faulty motor. | Check circuit breaker and power connections. Verify wiring against diagram. If motor is faulty, contact Intermatic support. |
| Load does not turn ON/OFF at programmed times. | Trippers incorrectly set; time dial not set to current time; faulty switch mechanism. | Ensure trippers are pushed in/out firmly. Verify current time setting. Check for obstructions to the switch lever. |
| Motor hums but dial does not turn. | Obstruction in gear train; motor issue. | Disconnect power and inspect for obstructions. If problem persists, contact Intermatic support. |
If troubleshooting steps do not resolve the issue, contact Intermatic customer support or a qualified electrician.
Specifications
- Model: T1906
- Type: 24-Hour SPDT Time Switch
- Voltage: 208-277 Volts
- Enclosure: 3R Indoor Steel Enclosure
- Dimensions (Product): Approximately 5.5 x 3.5 x 8.25 inches
- Weight: Approximately 2 pounds
- Maximum Operations: 96 (48 ON / 48 OFF) per 24 hours
- Minimum ON/OFF Time: 15 minutes
- Material: Steel
- Certification: CSA (Canada and US)
Warranty Information
For detailed warranty information, please refer to the manufacturer's official documentation or visit the Intermatic website. Warranty terms typically cover defects in materials and workmanship for a specified period from the date of purchase.
Customer Support
For technical assistance, replacement parts, or further inquiries, please contact Intermatic customer support. You can find contact information on the official Intermatic website or through your product retailer.
Intermatic Website: www.intermatic.com





