Accurate temperature control is essential in many industries. Whether you're heating, cooling or maintaining a specific environment for safety and product quality. But what exactly does temperature control mean and how do temperature controls and control panels make it happen?
In this guide we will break down how it works to help you make smart choices for your process systems. We will also describe custom control panels.
What Does the Term "Temperature Control" Refer To?
Temperature control refers to the process of maintaining a specific temperature within a system or environment. This is crucial in many industries such as manufacturing, food processing and laboratories where stable temperatures are required to ensure proper functioning, safety and acceptable product quality.
For example, in most industrial heating systems you need a reliable way to heat the product or equipment to a set temperature and maintain that setpoint for long periods of time. Without proper temperature control your system might overheat or underheat, leading to issues such as equipment failure, poor product quality or even dangerous situations. A key part of keeping the right temperature is by using a closed-loop control system. These systems can monitor and make accurate adjustments based on feedback from sensors.
What Is a PID Controller and Why Is It Important? 
A “PID” controller stands for Proportional, Integral and Derivative actions — three types of adjustments which work together to maintain temperature with precision. The following is a simplified way to understand this:
- Proportional (P): This adjusts the heating based on the difference between the current temperature and the desired setpoint. If the temperature is off, it reacts right away to bring it back in line.
- Integral (I): This part addresses small, accumulated errors over time, fixing any gradual temperature drift.
- Derivative (D): This predicts how the temperature is changing and makes adjustments to prevent overshoot or undershoot.
In closed-loop systems the feedback control system plays a critical role. “PID” action continually obtains feedback from the temperature sensor. The controller then adjusts the heating element power to keep the system at the desired temperature. The PID controller functions as a control algorithm, processing the sensor data and automatically makes corrective actions when necessary to bring the system back on track.
How Do Temperature Control Panels Work?
A temperature control panel is a group of electrical devices which allow you to manage the heating / cooling of a process system. This system connects to a sensor such as a thermocouple, to measure the actual temperature and adjust the heating element / cooling power based on that feedback.
Here’s a quick look at how panels can work for temperature control:
- Magnetic/Mechanical Contactors (PCM Models): These are simple systems which cycle heating elements on and off. While easy to use, they can have some delay in their response which can cause small temperature oscillations. For a basic control panel, something such as our part number PCM10082 should function adequately. This control panel utilizes a magnetic/mechanical contactor to control power to the heaters. This design provides one zone of control for your heating system. This type of panel is ideal for simpler applications where precise, fast adjustments are not as critical.
- Solid-State Relay (PCE Models): These panels offer faster and much more precise power adjustments. Solid-state relays can trigger heating elements quickly, making them ideal for applications where you need to react to temperature changes right away. The PID controller will pulse the Solid-State relay on and off very quickly to prevent overshoot on start-up and can maintain the setpoint much better than when used with a mechanical contactor. It also reacts to changes in temperature that are induced in the process, like the temperature drop on a bag sealer when a new bag is being sealed, or a fluid tank dispensing small amount of fluid, then adding fresh fluid to a heated fluid tank. Any process that takes heat away from the heater will trigger the control to add more heat without the fear of temperature spikes like in most On/Off control scenarios.
- Silicon Controlled Rectifier (PCS Models): These panels provide even more advanced performance and higher current capabilities. This allows adjustment of power to the heating elements smoothly and efficiently. These are perfect for radiant heat systems where the temperature should remain consistent without turning off the heating elements entirely. The SCR does this by chopping up the alternating current’s (AC) sine wave into infinite resolutions and can be controlled from zero to 100%. Designs of PCS models can include a TEC controller or just a dial. Many systems utilizing a conveyor system and radiant heaters or a heat tunnel don’t necessarily monitor the temperature of the tunnel or the product. They will use a combination of a speed pot on the conveyor speed and a dial pot on the PCS to dial-in the final desired result. An FM approved Hi-Limit could also be incorporated to prevent the heaters from exceeding their intended temperatures.
The feedback control system within these panels makes sure that any deviation from the desired temperature is corrected by adjusting the heating source. With PID closed-loop control, the system can continually monitor and control the process temperature at all times. This can also take action to keep everything within the set limits.
Key Features of Temperature Panels
When choosing a custom panel, you’ll need to consider several important factors to ensure it fits your system’s needs:
- Voltage and Power Requirements: First calculate how much power (watts) you will need to heat your product within the specified amount of time. See Heat Requirement Calculations in our Engineering Data section. Once the wattage is known, verify what voltages can be used in the facility. From that, you can calculate the amperage requirements. Ensure the panel can handle the voltage and current needed for your heating elements. For example, if you’re using multiple heaters, you’ll need a system to manage the combined power output.
- Multi-Zone Management: If you have several heating zones, a panel that can manage each one separately is essential. This is useful for larger systems where different areas need different temperatures or have different size loads.
- High-Limit Controllers: For safety, your system may require an FM approved high-limit controller to automatically shut off the system if the temperature exceeds a critical setpoint, preventing overheating. In most applications, the high-limit controller used must have “manual reset “so it does not automatically reconnect the heaters after being tripped. Also, FM (Factory Mutual) certification may be required. Our PCM2, PCE2 and PCS2 models all feature high-limit controllers.
- Safety and Monitoring Features: Many systems include lights or alarms, such as a “Ready” light to indicate when the system is up to operating temperatures, or beacon lights or buzzers to signal if something is wrong or time is up. For instance, a buzzer may sound when the ramp and soak cycle is done. You can also add meters or data loggers (PPS) to track power usage or record temperature changes.
Why Use a PID Temperature Controller?
PID temperature controllers are popular because they offer:
- Accurate Control: These controllers keep your process temperatures consistent, reducing fluctuations which can greatly affect product quality
- Fast Response: Unlike simple on/off systems, PID controllers adjust quickly to changes, making them ideal for applications that need precise temperature management.
- Automation: These controllers can be integrated into automated systems, allowing you to manage temperature adjustments without manual intervention.
In systems which require precise feedback control, the PID controller uses real-time temperature data for adjustments. This allows your process to be more efficient and reliable. This closed-loop type of system keeps your heating system running optimally, correcting small fluctuations in temperature before they become larger problems.

Customize Your Temperature Panel
When designing a custom temperature control panel, many options are available which allow it fit your exact needs:
- Multiple Temperature Zones: If you have multiple heaters or areas that require different temperatures, you may consider a system which allows independent control of each zone.
- Indicators and Alarms: Adding lights or alarms can let you know when something is off track. For example, alarm lights or ready lights signal when the system reaches the correct temperature or if there’s an issue.
- Receptacles for Easy Connections: Panels can be designed to include receptacles for plugging in heaters and sensors, making installation and maintenance easier.
- Special Features for Harsh Environments: If your system operates in tough conditions such wash-down areas or explosive environments, ensure the panel has the correct ratings such as explosion-proof enclosures or waterproof designs. Our standard catalog panels are built to NEMA type 1 specifications but can be customized for other NEMA Ratings. For more information check out our Standard NEMA Enclosure Ratings Guide.
What to Consider When Choosing a Temperature Panel
Here are a few key questions to consider when specifying a temperature panel:
What voltage can you provide? Make sure the panel matches your facility’s power supply (120 VAC, 240 VAC, 480 VAC, 50-60 Hz, single or 3-phase).
How many zones of control are required? If you have multiple heaters or heating areas, consider a system capable of managing each zone independently.
Do you need safety features? High-limit controllers can shut the system down if it overheats, ensuring safety. Do you want to be sure the power is off before someone accesses the panel? In this situation, you can add a door-latching rotary fused disconnect.
What environment will your control panel be used in? Make sure the panel can handle the conditions, whether it’s extreme heat, moisture, or hazardous areas.