Intermatic T103 Timer

The Intermatic T103 24-hour mechanical time switch is the industry standard for high-amperage load control in commercial and residential HVACR applications. Built with a rugged DPST (Double Pole Single Throw) configuration, this 120V mechanical timer is engineered to manage heavy-duty electrical loads up to 40A per pole. It serves as the direct replacement for Intermatic 1103 and 1103B models, fitting seamlessly into existing NEMA 1 indoor metal enclosures. Designed for precision scheduling, it supports up to 12 ON/OFF operations per day with a minimum 1-hour interval between events.

This heavy-duty 40 amp timer features teeter-type terminals that ensure secure power connections for multiple load types, including resistive, inductive, and tungsten. The manual override lever allows technicians to toggle the load without disrupting the set 24-hour schedule, providing essential flexibility during system maintenance or testing. Whether you are controlling pool pumps, indoor lighting, or industrial motors, the T103 mechanical switch delivers reliable timing with the highest motor load ratings available in its class.

• Maximum Load Capacity: Supports up to 40 Amps per pole, ideal for high-horsepower motors and industrial heating elements.
• Direct Retrofit: Engineered as a drop-in replacement for legacy 1103 and 1103B series mechanisms.
• Rugged Construction: Housed in a durable NEMA 1 metal enclosure designed for demanding indoor environments.
• Flexible Scheduling: Includes one set of ON/OFF trippers; supports up to 12 cycles per day for optimized energy management.
• Universal Installation: Teeter-type terminals simplify wiring for both solid and stranded copper conductors.

How do I wire the T103 timer for 120V applications?
Connect the 120V hot lead to Terminal 1 (Line) and the neutral to Terminal A to power the clock motor. For DPST operation, the load leads connect to Terminals 2 and 4. Always use copper wire rated for at least 90?C.

Can I add more than one ON/OFF cycle per day?
Yes. While the unit comes with one pair of trippers, you can install up to 12 sets (model 156T1978A) to handle complex cycling requirements.

Is the T103 compatible with outdoor installations?
The standard T103 comes in a NEMA 1 indoor enclosure. If the application is outdoors, the mechanism must be installed in a NEMA 3R rainproof enclosure.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.