Temperature Control in Electrical Enclosures

5 Plug & Play Solutions for Temperature Control

Temperature and humidity control in electrical enclosures exposed to extreme climate conditions can challenge panel designers.  Off-the-shelf products are available for commercial applications from ATMS to SADA systems.  Take the guesswork out of solving your temperature control problems.

When installing components in a new panel, it is essential to minimize the wiring and mounting complexity of the equipment.  Industrial grade components designed for mountain directly onto the DIN rails save time and reduce wiring and connections.

Four primary components will solve 99% of climate control problems inside electrical cabinets.

• Temperature controls
• Humidity controls
• Heating devices
• Cooling devices
• Condensate evaporators

Variations of size and output of the four basic types of controls can be found on the shelf and available for online purchases.  Look for industrial quality devices manufactured to National Electrical Standards with built-in mounting hardware.  Devices should be prewired or provide terminal blocks for connecting power.

Smaller devices will have predrilled flanges for direct mounting to surfaces.  The larger device should come with DIN mounting connections.  

Temperature controls for electrical enclosures

If both cooling and heating devices are used dual, purpose temperature control will be required. Sensors will monitor the temperature to a preset setpoint. The output will control heaters and cooling components like household thermostats heating and cooling.  

DBKUSA’s Dualstat is an excellent example of a 2-in-1 device.  The small controllers have built-in wiring connectors and can be mounted directly on the DIN rail.

See the Duastat specification here.

Humidity control for electrical cabinets

Electrical enclosures installed in high humidity areas may need a hydrostat, specially made for industrial applications and harsh conditions.  In combination with temperature controls, these devices can sense the humidity and activate heaters or coolers to maintain the temperature below the dew point.  This approach will prevent condensation from forming on cooler surfaces inside the cabinet.

Read more on how a hydrostat works and see DBK’s off-the-shelf solution.

One of the most often used heaters for electronic enclosures.

A PTC heater is preferred in electrical cabinets due to its durability and not needing separate temperature controls in many applications like outside ticket machines or traffic control systems.

With PTC, a positive temperature coefficient heater is a solid-state device that heats without combustion.  This makes them more durable than a traditional resistive wire type of heater.  The characteristics of the PTC name are derived from enabling them to automatically control current flow as the temperature rises to the desired temperature.

Read more on how PTC heating works.

See the wide range of off-the-shelf PTC heaters available online.

Peltier technology makes cooling more efficient.

Solid-state Peltier thermocoolers can solve many issues using outside air to cool internal components.

Cooling an electrical cabinet can be a challenge in remote locations.  Fans that bring in or exhaust air for cooling can be problematic.  The openings require dust filters, can bring in moist or contaminated air, and are usually not controlled for temperature changes.  Airconditioners and heat pumps also need outside air to be effective.

The thermoelectric coolers work by passing a current through two dissimilar metals, creating cooling. A built-in fan is used to move the cool air from the surface of the metal into the cabinet.  There is no requirement for outside air or cooling liquids.  

While needing a fan for circulation, the process has no other moving parts and is compact for use inside an electrical cabinet.  These devices are made for industrial use, but similar devices are now found in campers and RVs.

Learn more about how Peltier cooling works.

See the off-the-shelf Peltier cooler you can purchase online.

Removing condensation from a cabinet without drain lines

Cooling devices in electrical cabinets can create moisture as the dew point of the air is lowered.  This can pose several problems.  It is undesirable to have the condensation form on any of the electrical components.  Water and electricity don’t work well together.

If used, the Peltier cooler or dehumidifying devices are designed to collect moisture as condensate.  This creates a problem of what to do with the collected water.  Residential systems have a drain or pan to collect water.  These methods require an external outlet for the water to drain or manually empty the water from the pan.

Using a condensate evaporator can solve these issues.  Inside the evaporator where water is collected, a PTC heater is used to evaporate the water, turning it into water vapor or steam.  A hose exhausts the steam/vapor from the cabinet into the outside air.

The difference between a conventional drain and the enclosed evaporator hose is there is no outside air introduced through the opening and no water coming out of the cabinet to run off.

Learn more about condensate evaporators and the DBKUSA product.

Unique electrical cabinet thermal management applications.

This was a general guide to temperature control in electrical enclosures.  Enclosures and applications vary significantly, from the smallest cabinet used in medical equipment and aviation to large remote control enclosures for oil, gas, and other industries.

Power and output requirements also vary significantly with each application.  The devices you need may be online, off-the-shelf, or require custom engineering.  If you need more information or guidance on sizing products for your application, call our engineering department here in the US and talk with a thermal management engineer.