ProMation Engineering Achieves Key Milestone in High Temperature Applications

Spring Return Electric Actuators Meet Fire Standards for Tunnels

Brooksville, FL – ProMation Engineering Inc., a worldwide provider of electric motorized actuators for industrial use, has successfully completed a key milestone for international ventilation applications in rail and road tunnels and underground passenger platforms such as subway stations.

In an emergency situation such as a fire inside the structure, electric motor operated dampers in the ventilation system can act to suppress spreading of the fire as well as to clear smoke from the structure. Most motorized actuators that operate these dampers are required to be "fail-safe", where they are equipped with mechanical springs that close (or open) the damper upon loss of power at the actuator. Further, the motorized dampers must function at elevated temperatures to be effective.

The ProMation PA series of spring return quarter-turn, fail-safe electric actuators successfully performed a high temperature functional test, meeting standards and guidelines for the United States, United Kingdom, Austria, France, Switzerland, Sweden, Korea and the Netherlands. Not only did the actuators function after one hour at 482°F (250°C), they were fully operational after two hours at that temperature, a more severe test required more frequently as standards evolve.

The test actuators, a PA spring return unit with 450 in lbs (50 Nm) of torque and a PDO spring return unit with 2300 in lbs (260 Nm) of torque and equipped with a manual override mechanism were placed in an oven preheated to 482°F (250°C). The actuators were outfitted with specially designed thermal protection. Sensors monitored the temperature at various locations throughout the test. Once at temperature, the actuators were tested at 30, 60 and 120 minutes. The actuators were fully functional during the tests. Without the thermal protection, normal operating temperature for the spring return actuators is -20° to 150°F (-15° to 65°C).

After testing, both units were disassembled and inspected. While there was discoloration in places on the outside of the thermal layer; there was no observable damage to the internal components. Both test units met their operating specifications for cycle time, electronic operation and repeatability.

"The key reasons for the testing were to demonstrate the ability of our spring return actuators to meet the various country and local specifications for tunnel damper applications and to directly observe the performance of the actuator in an extremely adverse environment," remarked Dean J. Geraci, General Manager for ProMation Engineering. Brian Wheeler, Chief Technical Officer, added, "As part of our ongoing development initiatives, we continue our product testing and certification process as required by our customers and authorized bodies. These products were designed for use in safety systems and for emergency ventilation needed during a tunnel fire. The fail-safe spring return units must perform properly when needed."

ProMation Engineering provides electric actuation products and solutions for customers worldwide for industrial applications. Located in Brooksville, Florida, ProMation Engineering manufactures high quality industrial electric quarter-turn actuators ranging from 55 in lbs to 40,000 in lbs. The product design is based on a self-locking worm drive principle which provides for smooth running, dependable, robust drive system with an easy manual override feature.

For more information about ProMation Engineering:

call 352-544-8436,

Fax: 352-544-8439,



visit:, or

write: ProMation Engineering, Inc.

16138 Flight Path Drive

Brooksville, FL 34604


Dean J. Geraci


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