This power electronics enclosure for a test setup is full of high-power electronic components generating massive waste heat. A customer found that the cabinet’s internal temperature was rising above acceptable temperatures and came to ACT because they were worried about overheating electronics causing downtime during testing.
The cabinet is set up inside a dusty warehouse with an average ambient temperature of 21°C. The 15 heaters inside of the cabinet are 100W each and create approximately 450W of waste heat. Before implementing a cooling solution, the internal cabinet temperatures were reaching 48°C, on average. This was putting the internal power electronics above their maximum operating temperature of 43°C and causing stress on the electronics; over time this can result in a power failure. The customer was proactive and reached out to ACT before the excess temperatures led to overheating of the components in the cabinet, potentially ruining the test setup. Adding a heat exchanger helped regulate the internal temperature, and the choice of an ACT Sealed Enclosure Cooler was ideal because NEMA rated sealing gasket ensures that the cabinet is not impacted by the dusty warehouse environment. An added benefit is that by choosing a NEMA 4X-compliant model, washdown operations are possible.
Impact of Installing an ACT-HSC-22
ACT’s HSC-22 sealed enclosure cooling unit provided the customer with a sealed cooling solution for their power electronics cabinet.
After installing the ACT-HSC-22, the average internal temperature of the power electronics cabinet dropped to 35°C, which is far below the maximum operating temperature of 43°C. After operating the test equipment for 2 minutes the internal cabinet temperature readout was 38°C, remaining the average temperature throughout the test.
The customer was pleased with this solution that provided the needed cooling while preventing worries about filters and regular cleaning inside of the cabinet. They also expressed satisfaction that the unit was quieter than an air conditioner.
Overview of the Solution
Applications for sealed enclosure cooling can show up in a wide variety of applications. A well-known Pennsylvania theme park recently found three separate control cabinets that could be improved with a simple addition of an ACT Sealed Enclosure Cooler product.
Golf Course Sprinkler Control Cabinets
The theme park originally contacted ACT’s local automation control distributor to resolve an overheating problem related to their golf course sprinkler system. The sprinkler control panel contained a PLC and multiple drives that powered sprinkler motors. The cooling system for the control cabinet relied on pond water to cool the cabinet. During the winter, the feed lines to the internal cabinet’s water based cooler cracked, due to improper winterization of the system. You can imagine what occurred during spring start up: the entire cabinet was filled with water and the control panel components all had to be replaced.
When ACT was brought in to review the application, the customer requested the inside control cabinet air temperature be regulated at 95°F or below. The internal heat loads in the NEMA 4 cabinet were calculated as below 800 Watts and the actual heat rejection assistance of the control cabinet walls
was deemed to work towards reducing the overall heat load. The other advantage noted was that the system only ran at night, in order to keep golfers from getting wet. This night usage when the outside air in the evenings was under 70°F provided a hefty temperature delta of 25°F between the desired temperature inside of the enclosure, and the external outside ambient air temperature. The cabinets’ dimensions were measured as 48”H x 60”W x 12”D. The application data was run through the ACT Enclosure Cooling Selection Tool and the suggested result was an ACT-HSC-45 Heat Sink Cooler.
After installation, this HSC unit provided an average inside control cabinet temperature of 85.6F, well under the customer’s 95°F goal. Since the ACT-HSC-45 is completely sealed, the possibility of damage due to water or dust was eliminated.
Park Ride Control Cabinets
As a result of the success on the golf course, when one of the park’s facilities engineers noted that control cabinets near the amusement park rides were getting filled with dust and dirt, they again reached out to ACT. The parks ground keepers use leaf blowers to keep paths and rides clean of dust and leaf debris, but this effective cleaning method was causing a high level of dust and dirt contamination within the control cabinets, whose thermal management system was the typical fan cooler. While the fan coolers were originally installed with filters, when they became dirty, it was determined that the filters were often removed without being replaced.
Internal and external cabinet temperatures were measured and the heat loads was derived during an application assessment. The cabinet inputs and heat load once more aligned well with an ACT heat exchanger solution. This time an ACT-HPC (Heat Pipe Cooler) was applied as the narrow cabinets were only eight inches in depth. The foot print of the selected ACT-HPC was only 5” x 5” square and fit nicely into the cabinet.
After installation, this HPC unit has given the facility a reduced maintenance system leading to decreased down time on park rides. Eliminating dirt, dust and moisture reduced overheating problems resulting from clogged fans, and prevented bridging of electrical components, which caused intermittent signal problems or direct shorts.
Cabinets located in the Water Park
With the successes found around the theme park, upgrades for control cabinets near the large water park were recommended by facility managers. In this location, ACT-HPC, 316 Stainless heat pipe coolers, rated for NEMA 4X applications were applied. The 4X sealed rating indicates that this product will prevent water penetration, and therefore, corrosion damage to the ACT-HPC heat exchanger.
This NEMA 4X HPC solution provides a low-maintenance, long-life thermal solution that is able to keep a sealed environment, protecting the sensitive electronics in the control panels from water damage.
Advanced Cooling Technologies was able to address not only the original cabinet cooling issue for the Theme Park’s golf courses, but was able to leverage its product line and engineering expertise to become a valuable thermal partner to make improvements park-wide.
A US-based furniture manufacturing plant was experiencing problems with the system reliability of an industrial air conditioning (AC) unit. The AC unit was failing to provide essential cooling to an enclosure that housed programmable logic controllers (PLCs) and drives for computer numerical control (CNC) for wood cutting equipment.
To add to the problem, the AC units were from an Italian manufacturer, which naturally created long lead times for spare parts and/or replacement units. The downtime created delays in production, as each CNC unit builds a particular component of a piece of furniture. This caused deliveries to be late and resulted in unhappy customers.
To complicate matters, the operating conditions in the plant are dusty due to saw dust from the wood working. This challenge required the cooling system to be completely sealed – meaning that a cooling solution that allowed ambient, dusty factory air to flow directly through the enclosure was not suitable.
The in-plant ambient temperatures fluctuated greatly depending on season, from 65° F in winter to 100°F in summer. The calculated thermal loads from the PLCs and CNCs were approximately 1,200 Watts. The plant facilities manager had found that the equipment had a tendency to trip out when temperatures exceeded 125°F.
With the reliability issues, failures of the AC unit, and dusty and hot environmental conditions, the plant facilities team needed a better solution.
The Thermal Management Experts at ACT visited the manufacturing plant to assess the problem. It was clear that the actual electrical component sizes and location of the enclosures would require an appropriate cooling solution.
Typically, ACT works from the worst-case environmental temperature scenario to determine the proper solution. In this case, the hottest environmental temperatures occurred in summer. A scenario case was calculated with ACT’s Enclosure Cooling Selection Tool. The size, load, and unexposed side details of the enclosure were input to the Selection Tool. The maximum 25°F summer time temperature delta between the enclosure electronics and outside enclosure ambient temperature made it possible to offer an above-ambient cooling solution. Above-ambient cooling solutions require the inside of the enclosure to be hotter than the outside of the enclosure. These conditions existed in this case, so the ACT heat exchanger could most optimally perform cooling by heat rejection.
The selection tool calculation suggested an ACT-HSC-68 Heat Sink Cooler as the optimal solution. The ACT-HSC-68 is capable of cooling a 1,360 Watt internal enclosure heat load..
Based on the selection result and the on-site visit, the facilities team decided to move forward with ACT’s suggested solution. The successful installation first called for a custom plate to cover the existing AC unit cutout, and then a new mounting cutout made to fit the ACT-HSC-68 Heat Sink Cooler.
The true test of the system arose in July 2018, when the plant encountered two weeks of summer heat, causing a 95-100°F plant working environment. The cabinet was fitted with a temperature monitor to measure the performance of the ACT-HSC-68.
After the two weeks of peak summer heat, there were no drive system trips or faults due to overheating. The internal cabinet temperatures were kept under 100°F by the ACT-HSC-68 Heat Sink Cooler.
There were three additional benefits to ACT’s cooling solution: one is availability to spare parts and new units from a US-based manufacturer (ACT is located in Lancaster, PA.); second, the price of the system was 40% that of an AC unit; and third, operating cost was reduced approximately $350 (AC unit operation cost of $400/year vs. the ACT-HSC-68 operation cost under $60/year).
ACT supports the installation process with technical installation videos and dedicated engineering files in both CAD and SolidWorks STEP formats.