Wattco Control Panels In-Depth

Wattco control panels are designed to maintain reliable and efficient heat transfer in a heating system and to keep an industrial process running at full operational capacity. Wattco control panels and heaters have been keeping industrial fluids from chemical disintegration with precise heat control for over 40 years and we are constantly striving to improve our products and their performance. We also offer entirely custom control panel manufacturing services to meet the exact requirements of your target application. Nearly every component of the control panel is customizable to suit hazardous environments or protect against moisture, dust, or other hazards.

Types of Wattco Control Panels

There are as many types of control panels as there are industries and applications, but they can be separated into five categories. These categories are listed below.

Temperature Control

A temperature control panel is designed to change the temperature of a space and the fluid contained within. These control panels detect the fluid’s temperature then compare it to what the control panel is programmed to hold as the desired temperature. If the two values are not equal, the temperature control panel will send a signal to the heating element to make the fluid reach the appropriate temperature.  Wattco-control-panel-front-view

Power Control

An electrical power control panel distributes and controls the flow of electrical energy through a system. It can be used to regulate current and voltage and deliver them to a subsystem or component as required.  

Multi-Loop Controller

A multi-loop controller is a type of control panel used to control temperature or process components in an industrial system which has two or more control loops within one system or unit.

Process Controller

Process control is a facet of engineering related to ensuring the output of a process falls within the desired range by manipulating the system’s mechanisms and construction to stay within peak operational parameters. A process control panel is a tool which enables the engineer or technician to control process components.

Safety-Limit Controller

A safety-limit controller is designed to help prevent damage to a system and its components through a variety of control functions. For example, the safety-limit controller may monitor the current running past a section of a system and temporarily deactivate the flow of power to that section if the current reaches a level which could damage the system or harm someone.

Control Panel Construction

Although control panel construction materials differ depending on the application they are intended for, the basic design of most control panels is similar. The variations between models for different applications are listed below.  

Control Panel Boxes

Our control panels are designed and built to deliver dependable performance consistently over a long operational life. We design and build our systems following NEMA standards – a set of standards defined by the National Electrical Manufacturers Association to delineate different grades of enclosures for electrical circuitry, often for industrial use. NEMA enclosures are designed and built to protect staff from unsafe exposure to electrical equipment and to protect the equipment from being damaged by environmental factors.

Each level of NEMA standards is rated to prevent a different degree of adverse conditions. On the lower end of the protection spectrum, NEMA control panel enclosures are rated to protect against contaminants such as water, dust, oil, gasoline, acetylene, or other corrosive agents and gasses. Below is a complete list of NEMA accreditations applied to control panel enclosures. Bear in mind that a NEMA box with a higher rating does not include all of the features of lower-rated NEMA boxes.

For example, a NEMA 10 enclosure is rated for use in a mine and tested against the hazardous found in that type of environment, namely dust and dripping water. Although a NEMA 4 box is rated for those hazards and more, the NEMA 10 does not share those other qualities.   

Below you’ll find a list of all available NEMA control panel enclosures.

NEMA Control Panel Levels


Protects Against

1 NEMA 1 boxes are general-purpose enclosures and are mainly used to prevent human contact with electrical circuitry.  These boxes should be used indoors in normal conditions.
2 These boxes are tested to be drip-tight, meaning their drip shields allow them to be used in locations with severe condensation.
3, 3R & 3S NEMA 3 boxes are are resistant to most weather and are suitable for outdoor applications. These enclosures are tested to protect against dirt, dust blown by the wind, weather like rain and snow, and even damage from ice. This model is most often used on construction sites and in subway and road tunnels.  Note: NEMA 3R does not protect against high-velocity dust while the 3S can operate while covered in ice.
3X, 3RX, 3SX An X after the number means the enclosure is rated to protect against corrosion. This series of NEMA boxes are often applied in processess which use salt water.
4, 4X These boxes are watertight except under certain conditions. Visit the NEMA website for more information. These control panel enclosures are often used in outdoor applications, near water, or in processes which involve a great deal of liquid and moisture.
5 Dust-tight. Provided with gaskets or equivalent to keep out dust; used in steel mills and cement plants.
6 and 6P Nema 6 boxes are completely submersible in water and/or oils. These enclosures are used in situations where submersion may occur. The standard model can be submerged for a short time while the 6P can withstand longer submersions. These boxes are not intended for permanent submersion.
7 Certified and labeled for use in areas with specific hazardous conditions: for indoor use in Class I, Groups A, B, C, and D environments as defined in NFPA standards such as the NEC.
8 Certified and labeled for use in areas with specific hazardous conditions: for indoor and outdoor use in locations classified as Class I, Groups A, B, C, and D as defined in NFPA standards such as the NEC.
9 Certified and labeled for use in areas with specific hazardous conditions: for indoor and outdoor use in locations classified as Class II, Groups E, F, or G as defined in NFPA standards such as the NEC.
10 MSHA. Meets the requirements of the Mine Safety and Health Administration, 30 CFR Part 18 (1978).
11 General-purpose. Protects against the corrosive effects of liquids and gasses. Meets drip and corrosion-resistance tests.
12 and 12K General-purpose. Intended for indoor use, provides some protection against dust, falling dirt, and dripping non-corrosive liquids. Meets drip, dust, and rust resistance tests.
13 General-purpose. Primarily used to provide protection against dust, spraying of water and non-corrosive coolants. Meets oil exclusion and rust resistance design tests.

Standard Control Panel Features

Below is a complete list of features which come standard on Wattco control panels. Special accommodations can be made upon request. Simply inform a Wattco representative of your requirements and he or she will find a solution for you.  

  • Voltage capacity up to 4,000 A, 600 V
  • Basic model comes with remote mounted control if required
  • Full-featured model comes with:
    • A power switching contactor
    • A stage contactor
    • Switching in solid state
  • Every control panel package shipped by Wattco includes:
    • CAD design drawings for your records
    • Bills of material
    • An array of replacement parts
    • Operating instructions
    • Manuals for each component

  The following additional features are available according to your requirements:  

  • Remote point setting
  • Proportioning capacity
  • Automatically-activated alarms
  • Process-variable retransmission
  • Peak-load & dual-energy controls
  • PLCs for current, voltage, and wattage metering and interfacing

  For a comprehensive list of control panel models, features, and extra features available through Wattco, look through our online control panel catalogue.


The functional features of each Wattco control panel translate into concrete benefits for your operation. You can depend on Wattco’s control panels to hold up when you need them and minimize downtime. By using a Wattco control panel you reduce costs and improve efficiency. Install your Wattco control panel and integrate it into any compatible system straight out of the box – they ship ready-to-connect. Our control panels can also be built to suit to withstand various hazards and environments including dust, oil, water, and corrosive solutions.

Control Panel Accessories

Different models of Wattco control panels ship with different accessories. If your application is niche, Wattco can create a custom control panel with virtually any combination of accessories and features. Some of the most common accessories are listed below. 

TBR Industrial Thermostats

These thermostats integrate with our control panels to give fast, accurate temperature readings. Appropriate applications for one of these thermostats are industrial applications requiring no close control of process temperatures. The thermostat’s terminal bulb and capillaries are made of copper and plated in nickel or stainless steel for long-lasting performance. Some applications require further protection in the form of a protective well for temperature readings or a protective coating. Protective wells are supplied as a standard feature with Wattco control panels.

For most applications, we use a welded tube of superalloy called Incoloy and fit it with stainless bushings. Some more corrosive applications require special wells. Inform a Wattco representative if you are concerned your application might require additional protection. A neon pilot light accessory is also available, but there is separate shipping for field mounting and wiring. If you require controls with no built-in fitting please contact us.


Reostats, more commonly referred to as, “potentiometers,” are a type of two-terminal variable resistors with a sliding or rotating contact used to divide voltage. The reostat is used to measure electrical potential, commonly used in control applications.

THI High Limits

A THI high ensures equipment is working within operational parameters. Potential safety risks exist in abundance in industrial processes involving heavy machinery – staff and equipment are at risk due to malfunction, loss of liquid or airflow, so the THI high limit is mandatory for use with control thermostats.


Thermocouples are devices designed for temperature measurement comprised of two wires made of different materials which are connected at two points. The voltage difference between the two materials is proportional to the temperature difference. Thermocouples are used with electronic temperature sensing equipment. For a complete list of available thermocouples contact us or consult our control panel brochure.


Depending on your application you may need thermocouple junctions of various constructions. Below you’ll find the different standard junction styles.

Grounded Junction

Grounded junctions are created by welding in an inert atmosphere so that the two thermocouple wires can be incorporated with the sheath weld closure. The electrical ground is achieved through the sheath in this arrangement. Be aware that a grounded junction has a slower response than exposed wire, although the wires are protected from mechanical damage and won’t be exposed to environmental hazards, making them more likely to last longer.  It is also pressure tight above 100,000 PSI. To avoid pulling a part of hot junction, the coefficient of expansion wire must be similar to that of the sheath.

Ungrounded Junction

An ungrounded junction is similar in construction to a grounded junction, only the thermocouple wires are made into a junction and insulated from the sheath and sheath closure. This closure is formed by through welding without the thermocouple wires. The thermocouple isn’t ground in relation to the sheath material. The ungrounded junction shares most of the features with the grounded junction, with the exception of having differential expansion between wires and sheath.

Weld Pad Junction

Weld pad junctions are used as fasteners between thermocouples and surfaces (for example plates and tubes), with the effect of providing efficient, accurate measurement of surface temperature. The composition of the weld pad junction is the same material as the sheath but it comes in parallel, perpendicular, or tube formats.

Exposed Junction

An exposed junction has thermocouple wires exposed because the sheath and insulating material are removed. The joined wires make a measuring junction with a but weld, making for a faster response. The exposed junction is more vulnerable to mechanical and environmental hazards but is still used in many applications which require the fastest possible response time. The service life of an exposed junction is shorter and the system is not pressure-tight, however, certain applications require a junction set up with the fastest response time.

Sheath Materials

Wattco can build sheaths from practically any material, but the most standard materials and their benefits are listed below for your convenience.

304 Stainless Steel 310 Stainless Steel 316 Stainless Steel 800 Inconel
For general purpose applications. Cost-effective and economical choice. Abundance in supply and therefore readily available. Carbide precipitation induced in the 480℃ to 870℃ range. Has a maximum operational temperature of 900℃. Preferred over 304 Stainless steel in high-temperature demanding applications. Out of the 300 series of stainless steel, this one offers the best corrosion resistant sheath material to oxidation. Maximum operating temperature is 1150℃. 316 Stainless steel is superior to both 304 and 310 steels in terms of corrosion resistance. Most commonly used in the food processing industry. Perfect suitability for use with sulphuric acid compounds. Maximum operating temperature of 900℃. An alloy comprised of high nickel and high chromium content designed for resistance to oxidizing and reducing environments. Also suitable for high-temperature applications in corrosive environments. Often used in furnaces, or in chemical or food processing hardware. Maximum operating temperature of 1150.℃

Ordering Your Wattco Control Panel

If you’re ready to consider getting a Wattco control panel for your industrial process or operation, you can start by filling out our contact form or calling us at 1800-492-8826. Our control panels can integrate with virtually all systems, and we can customize a control panel to suit your needs. Wattco also offers quotes within 24 hours and has some of the fastest shipping in the industry.