A lot of emphasis is given to industrial heating elements and sheath materials when discussing the electric heaters. However, equally important are the control panels for process heaters to function effectively. The control panel is a vital part of the immersion heaters to maintain stability. Failure to control the temperature may result in overheating and thus causing the deterioration of the medium that is being heated. WATTCO™ makes it a point to design digital control panels for extreme efficiency and incorporates the NEMA standards to ensure maximum performance.

There are several components to the control panel—also called control box or terminal enclosure. There are primarily internal wirings, switches, fuses, and heat sensing mechanisms such as RTD. The heat sensing mechanism can also be resistance thermocouples. It works in place of RTD to act as a device that controls the heater to turn on or off automatically in conjunction with other circuits) in order to maintain the heat consistency. RTD is basically Resistance Temperature Detector in the technical term for resistance thermometer, and in simple term acts as a thermostat.

Thermocouple/RTD is responsible for detecting temperature variance and controlling the flow of heat with the logic board that regulates the switch to the heater. The differences between these are mainly costs and performance issues. Typically, thermocouples are cost friendly over RTDs. They are also simple and fast in response. The operation mode is suitable in high temperature with tip temperature sensing. There are downsides as they are the least sensitive and least stable in comparison to RTDs.

The RTD solution costs more, but offers several advantages. Its operating mode is area sensitive, and therefore RTD provides good stability and excellent accuracy. Unlike thermocouples, RTD is good in linearity, and contamination resistant. However, it is not without shortcomings. It is slower in response time, and at times self-heating. More importantly, it is less sensitive to small temperature changes. Deciding on the use of thermocouple/RTD is not a simple matter of this and that. A lot of factors must be weighed before making an intelligent decision.

Thermocouple/RTD choice aside, the importance of control panels cannot be overstated for making the immersion heaters efficient and effective. The reliability of control panels begins with the housing that protects the control panel from outside factors. NEMA standards are therefore an important step forward to ensuring the reliability of control panels. WATTCO™ currently uses 3 different NEMA compliant thermal enclosures. NEMA 1 is suitable for all standard/non-hazardous operations that usually take place in the normal course of factories. NEMA 4 is robustly designed for outdoor purpose. Its 4 times normal moisture protection is perfect to be weather resistant. WATTCO™ additionally features NEMA 7 box that is resistant to explosion. It is an ideal choice for hazardous environmental conditions such as fire.

The essence of digital control panels is about precision. The precision requirement dictates each scenario differently. The digital controls are installed to monitor the ambient and set-point temperature. The control panels can be customized for the application specific need. The digital controls are reliable and cost-effective. The digital control panels can maximize the heater performance while providing a hassle-free care over the entire operation of your immersion heaters.
 
Get a quote on a control panel today or browse through all of WATTCO’s products.