Intermatic WH40 Timer Control

The Intermatic WH40 is a heavy-duty mechanical water heater timer designed for precise industrial and residential load management. Engineered as a DPST (Double Pole Single Throw) switch, this 40-amp control handles up to 10,000 watts at 208-250 VAC, making it the industry standard for reducing energy costs by shifting water heater operation to off-peak utility hours. The rugged NEMA 1 indoor steel enclosure houses a reliable 24-hour yellow dial that supports up to 12 ON/OFF events per day with a minimum switching interval of one hour.

For service professionals, the WH40 provides a critical external manual override lever, allowing for immediate status changes without disrupting the master schedule. Unlike the T104 series, the integrated override on this 250V water heater timer ensures contractors can verify system functionality or provide temporary hot water access instantly. The unit features 1/2-inch and 3/4-inch knockouts and teeter-type terminals for consistent, high-torque electrical connections using copper conductors only.

Key Benefits

• High Amperage Capacity: Rated for 40 amps per pole, capable of controlling high-wattage electric water heaters or agricultural equipment.
• Industrial Durability: The NEMA 1 enclosure provides a secure, tamper-resistant housing for long-term reliability in mechanical rooms.
• Flexible Scheduling: Includes two sets of trippers for multiple daily cycles, optimizing off-peak electricity use for maximum ROI.
• Simplified Service: The manual lever reverses the current program until the next scheduled tripper, facilitating easier maintenance and troubleshooting.
• Broad Compatibility: Supports 208V, 240V, and 277V 60Hz configurations for versatile job site application.

Common Questions

How do I wire the Intermatic WH40 for a standard 240V water heater?
Connect two hot leads to the Line 1 and Line 2 terminals; the clock motor is pre-wired to terminals 1 and 3. Always use a dedicated ground screw and ensure all connections utilize solid copper wire to prevent overheating.

Why is the manual override lever not responding immediately?
The mechanical design includes a 15-minute lockout period following an automatic operation to protect the motor and gear assembly; wait for this window to pass for manual control to resume.

Can this timer be used for applications other than water heaters?
Yes, with a 5 HP motor rating at 240V, it is frequently used for greenhouse misting control, agriculture feeders, and heavy-duty lighting circuits.

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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.