Equipment breakdown is not always predictable. Undesirable parameter values, harmful external events, and unknown mechanical failures can render process equipment completely helpless. C2i™ Technology has the ability to remedy unacceptable conditions and tolerate certain mechanical failures to keep your process running safely and securely until the specified fault can be properly addressed.
Undesirable Parameter Values
Traditional linear-resistant electric heating elements employ Magnesium Oxide (MgO) to provide the necessary dielectric strength or electrical isolation from the heater coil to the outer sheath. The MgO however, is inherently hygroscopic, which means it naturally absorbs moisture. When excessive moisture contaminates the MgO the dielectric strength becomes compromised. During lengthy inactive periods, the moisture content may exceed a safe limit, allowing internal arcing to take place when the element is activated. Unless the moisture is removed, catastrophic heater failure can occur which can destroy equipment, shut down entire processes, and cause significant production losses.
The solution to this problem is to utilize controllers with sophisticated C2i™ parameter monitoring technology that sense when heating elements contain moisture and understand how to remedy the condition.
The dielectric strength of a heater can be monitored by the amount of leakage current within each circuit. As the dielectric strength deteriorates, the leakage current, which is measured in milliamps (mA), increases. High leakage current levels typically occur at system startup since the heater has been de-energized long enough for it to absorb moisture. In this instance, controllers with C2i™ Technology detect the elevated leakage current and enable one of several proprietary soft start algorithms, such as a current limiting output. This control method reduces the output power to a safe level so that no damage to the electric heater occurs until the moisture is driven out of the element. Both the output power and the duration of the soft start profile are programmable by the user.
In the event that the current leakage level exceeds the maximum allowable limit during normal operation, our industry exclusive C2i™ Technology controllers automatically reduce output power to 15% and switch the control firing mode from Zero Cross to Phase Angle. The controller will remain in this control mode until the leakage current parameter value returns to a safe level.
By utilizing controllers with C2i™ Technology in applications where moisture can be detrimental, heater life is greatly extended, system safety and process integrity is significantly improved and operational costs are reduced.
Harmful External Events
Events external to the process, such as sudden significant current or voltage surges, can damage electronic and mechanical components and be detrimental to process equipment resulting in an unplanned system shut down.
In applications susceptible to intermittent short-circuits and voltage overloads, Chromalox power controllers with C2i™ Technology are able to manage these events and can be programmed to restore power automatically or manually when the fault has cleared, preventing complete process shutdown and maintaining production. These controllers continuously monitor the load current and instantaneously isolate the power switching device if the load exceeds a pre-set threshold. The controller automatically enters into a soft-start control mode after current is restored. During this ramp-up time, the firmware tests for any permanent short circuits and once again cuts the power should any exist. This prevents further system damage in the event that the fault is not effectively cleared.
This patented C2i™ fault-protection feature eliminates the need for extra-rapid fuses, reduces machine downtime and the costs associated with replacing fuses. By reacting immediately and tolerating the harmful event, this C2i™ Technology also prevents increased operating costs associated with process equipment damage and product loss.
Without warning, critical system components such as temperature sensors, can fail or be inadvertently damaged. Excessive corrosion or vibration, exposure to extreme temperatures and even human error can contribute to unexpected sensor failures. In most control systems, the process controller does not know how to properly behave when the expected sensor input signal is not received. As a result, controllers resort to default output settings as a safety precaution. In many cases, alarms are enabled and the heater output is set to zero percent, which brings the process to a halt.
This unplanned downtime, production stoppage and potential loss of valuable material can be avoided with C2i™ Technology. Chromalox utilizes exclusive controller features and developed control technologies to efficiently manage sensor faults and failures.
Chromalox offers controllers that can be programmed with a default heater output from 0% to 100% when presented with a sensor fault condition. This permits an enhanced level of process reliability and allows the owner to maintain production at a compromised level of control until the sensor problem can be properly addressed.
Particularly vital systems demand uninterrupted heater output and full process control. In these cases, a predetermined heater output level is an unacceptable solution to a failed sensor condition. Chromalox’s unique and powerful sensor mapping feature solves this problem by providing multiple layers of sensor redundancy. This developed control technology permits up to 252 sensor inputs per circuit and the output behavior can be based on the minimum, maximum, or average sensed temperature of all sensors mapped to that particular circuit. Additionally, a sensor alarm will be enabled should any sensor fail within that circuit. This C2i™ Technology lowers operating costs and provides the user with unmatched flexibility and security, thus ensuring 100% system reliability through continuous system uptime and complete process control.
System Integration Expertise
In today’s sophisticated industrial systems it is impractical to have process heating equipment which may only be monitored locally.
To ensure complete system awareness and safety, all process equipment must efficiently communicate with centralized control centers and provide real-time system wide health status. To satisfy these needs, C2i™ Technology provides expert systemwide integration using a multitude of widely accepted industrial protocols and developed supervisory control technologies.
Industrial companies utilize a distributed control system (DCS) to remotely communicate with all significant process systems throughout their facilities. Chromalox offers several Fieldbus protocols, such as Profibus, ProfiNet, DeviceNet, Modbus, EtherCAT, and several others, which provide the necessary language and connectivity for proper remote equipment monitoring and parameter management. In addition, Chromalox has developed an industry exclusive wireless temperature sensing C2i™ Technology which permits Chromalox heat trace controllers to seamlessly integrate with existing WirelessHART protocol networks. This capability solves remote application challenges where wired temperature sensing becomes cost prohibitive.
Understanding equipment health status of multiple control systems requires an effective and comprehensive integrated central monitoring solution. Chromalox’s C2i™ supervisory control technology is just that. It efficiently provides remote monitoring and value management of each parameter on every heater circuit across all control systems.
However, monitoring a large volume of circuits can be difficult to manage. Such complexity can lead to missed alarm events as well as an overwhelming amount of nuisance alarm notifications. The Chromalox proprietary engineered software technology continuously provides instant alarm event visibility from five different resolution levels as well as selective alarm announcement control. As a result, this well-organized C2i™ supervisory control technology lowers operating costs and improves system reliability by efficiently providing total system health awareness and eliminating missed alarm events.