Intermatic T104 24-Hour Mechanical Timer Switch - Heavy-Duty DPST

In this review the Intermatic T104 emerges as a straightforward, heavy-duty 24-hour mechanical time switch for professionals and homeowners who need dependable scheduled control of high-voltage equipment. The biggest reason to buy is its ability to control both legs of a 208/277V circuit with a DOUBLE POLE, SINGLE THROW design and a 40 A rating, which makes it suited for pumps, compressors, and commercial lighting where robust, manual-style scheduling is required.

Key Features

• Double pole DPST: Controls both legs of a 208/277V circuit for safer switching of high-voltage loads.
• 40 Amp heavy-duty rating: Supports motors up to 5 HP at 240V and a wide range of resistive and inductive loads for demanding applications.
• 24-hour mechanical scheduling: Allows up to 12 on/off cycles per day with a 1-hour minimum interval for simple daily automation.
• Industrial metal enclosure: Type 1 gray steel housing provides a secure indoor mounting point in mechanical rooms and control panels.
• Trippers included: Ships with one on and one off tripper for quick initial setup and easy adjustments.
• Wide voltage compatibility: Rated for loads from 120 to 277V and CSA/UL listed for reliability across installations.

Who It's For

The T104 is best for electricians, maintenance technicians, and contractors who need a rugged, no-frills time switch for indoor mechanical rooms, pump basins, or HVAC control panels. Its DPST switching and high ampacity make it especially appropriate where both legs of a high-voltage circuit must be disconnected and where motor loads are present.

It is less suitable for users who need minute-level precision, outdoor weatherproofing, or networked/smart scheduling features; those customers should look at electronic or outdoor-rated timers instead.

Pros & Cons

Pros

• High 40 A per pole rating handles motors and heavy loads without additional relays.
• Simple mechanical dial and included trippers make setup fast and intuitive.
• Durable metal enclosure designed for secure indoor mounting in equipment rooms.

Cons

• Mechanical design limits schedule granularity to 1-hour increments and lacks digital features like remote control.
• Not rated for outdoor installation, so weather-exposed locations require alternate products.

Specifications

Our Verdict

The Intermatic T104 is a reliable, value-oriented mechanical time switch for indoor industrial and commercial use where robust DPST switching and high amp capacity are required. It is an economical choice for contractors and facilities that need simple daily scheduling of pumps, lights, or HVAC compressors and prefer proven mechanical controls over digital complexity.

Frequently Asked Questions

Can this timer control a 240V motor?
Yes. The T104 is rated to handle motor loads up to 5 HP at 240V and switches both legs of a 208/277V circuit.

Is the enclosure weatherproof for outdoor use?
No. The unit has a Type 1 indoor metal enclosure and is not rated for outdoor installations or direct weather exposure.

How precise is the schedule?
The mechanical dial allows up to 12 on/off events per day with a 1-hour minimum interval, so it does not provide minute-level precision or advanced programming.