Fire suppression systems can come equipped with several accessories to enhance safety and performance. One such add-on is an engine shutdown package. This package automatically powers down the heavy equipment engine and radiator fan when the fire suppression system discharges. The benefit? Shutting down the engine helps to reduce or eliminate the fire’s fuel source and decreases the chance of fire reignition.
With this in mind, is it necessary to add an engine shutdown package to your equipment’s fire suppression system? Let’s explore some commonly asked questions about engine shutdown as well as some key factors to consider before moving forward.
What is Engine Shutdown?
The engine shutdown feature is an add-on for fire suppression systems and interfaces with the heavy equipment being protected, shutting down the engine when the system is activated. In certain scenarios, engine shutdown is a requirement by the National Fire Protection Association (NFPA), specifically Standards 120 and 122.
How Does Engine Shutdown Factor into a Fire Suppression System?
Engine shutdown is especially useful in helping to limit damage from fires intensified by hydraulic fluids or fuel. If the fire was ignited by a ruptured hydraulic line or the failure of a fuel line component, a running engine will continue to feed the fire with fluid or fuel. This can turn a small fire into an uncontrolled blaze.
The engine shutdown feature also shuts down the radiator fan. A fan can exhaust dry chemical agent from the engine compartment, reducing the fire suppression system's efficiency. A fan that continues to run may also provide enough oxygen to fuel the fire and intensify it.
Why is Engine Shutdown Important During a Fire?
When there's a fire, the equipment operator's first instinct is self-preservation. In their quick attempt to escape, they might fail to turn off the engine manually. Automatically shutting down the engine as the fire suppression system discharges can reduce or eliminate the fire's fuel source, increasing the probability of complete extinguishment of the fire.
How Does the Engine Shutdown Feature Work?
Engine shutdown functionality depends on the equipment. But this is how it works in general… and we’re getting a little technical here:
- A normally closed pressure switch is spliced into the positive (+) electrical line of the equipment's fuel pump.
- The switch is also piped into the actuation line of the fire suppression system.
- When the system is actuated, pressure from the nitrogen gas cartridge opens the switch, interrupting the electrical circuit to the fuel pump.
- This shuts down the pump, stopping the flow of fuel, which shuts down the engine.
The speed of engine shutdown depends on which circuit is being used to power down the engine. If spliced into the fuel pump, it generally takes five to eight seconds from system actuation to turn off the engine.
What are Key Factors to Consider Before Installing Engine Shutdown?
The most important factor to consider with an engine shutdown package is operator safety. Sudden engine stoppage may cause an operator to struggle to maintain control of the machine. An abrupt halt in hydraulic power once the engine stops can also cause additional operator safety hazards.
Rubber-tired equipment is generally highly mobile and requires a thorough evaluation to determine usage of the engine shutdown feature. Should engine shutdown occur while maneuvering over combustible materials or operating at higher speeds, a sudden loss of control could jeopardize the safety of the operator. This makes having the ability to delay the engine shutdown feature via an in-cab control panel very important.
For more information about fire suppression systems and the engine shutdown add-on, please contact us at email@example.com or 919-781-6610.