Increasing automation of industrial systems for harsh and potentially explosive environments, including production lines, industrial robotics systems, energy infrastructure, refineries, and semiconductor manufacturing lines. The industrial power supply selected by the system designer shall not only meet the requirements of high peak power and power supply backflow protection, but also meet the requirements of reliability, durability, safety, high power density, high efficiency and various complex regulatory compliance requirements.
This paper discusses the challenges faced by power system designers for demanding automation applications. The DIN rail power supplies for TRACO Power are then presented, explaining how they help designers meet these challenges.
Challenges of industrial power supply
Electronic equipment and systems are exposed to harsh industrial environments for manufacturing lines, renewable energy systems, distribution warehouses, and chemical processing facilities. Electronic equipment may be exposed to extreme temperatures, humidity, mechanical shock, electromagnetic interference (EMI), vibration, dust, chemical contact, and explosive atmospheres. Because electronics are widely used in power, control, and monitoring, all of these applications must be designed to ensure accuracy, accuracy, reliability, and safety.
Power supply is critical. As the core component of industrial electronic equipment, industrial power supply supports AC and DC regulated power supply. Its output must meet the basic energy consumption requirements of the connected equipment, and sufficient safety margin shall be reserved. For example, electromechanical systems such as motors, pumps, and motion control drives require very high peak currents at startup and industrial power supplies must be able to provide these currents. In general, the industrial power supply shall also have overvoltage, overcurrent and overheating protection functions.
The power supply must have good voltage regulation capacity when the load or line changes, and ensure high efficiency. This is particularly important for power supplies installed in compact enclosures, where low efficiency can lead to excessive heat build-up.
Outline specifications for industrial power supplies are also important. The industrial power supply must be able to be installed in machines or control cabinets with limited space. In addition, industrial applications require fast replacement of defective equipment, so the equipment shall be installed to facilitate removal and replacement. It is essential that industrial power supplies are certified for safety and electromagnetic compatibility (EMC).
Hazardous Location Certification
Hazardous locations (HazLoc) are a specific area of certification. The National Electrical Code (NEC) defines a hazardous location as an area where the presence of flammable gases or vapors, flammable liquids, flammable dust, flammable fibers, or flying lint could result in a fire or explosion hazard. Industrial power supplies and other electronic equipment must be specifically certified to operate in a HazLoc environment.
Underwriters Laboratories (UL), in conjunction with the European Union's Equipment for Explosive Atmospheres Directive (ATEX), establishes test standards for components used in hazardous locations. Such certification can prove that the certified equipment has met the minimum relevant safety standards required for use in the designated hazardous area.
The certification considers two factors: the type of volatile matter and the likelihood of its presence. The type of potential explosive determines the certification category. Class 1 includes flammable vapors and gases; Category 2 includes combustible dust, such as flour; Category 3 is combustible fibres and flyings (small volumes of combustible particles such as fabrics).
The existence probability of volatile hazardous substances determines the zoning type of hazardous areas. Division 1 covers environments where hazardous materials are normally present. Division 2 covers environments where hazardous materials are not normally present, but may be present under certain conditions.
Industrial power supply for HazLoc applications
TRACO Power's DIN rail TIB-EX series high-efficiency power supply (Figure 1) is designed for harsh environments and hazardous locations. DIN rail is a kind of metal rail widely used to install industrial control equipment in equipment rack or panel cabinet. The series also offers side-mount options for lower mounting profile to suit panel mounting requirements. This series of power supplies complies with UL HazLoc Class 1, Division 2 (C1D2) and ATEX (EN60079-0, EN60079-7, and EN60079-15) safety standards and is EMC certified.
TIB-EX DIN rail power supply for TRACO Power
Figure 1: TIB-EX series DIN rail power supplies are HazLoc C1D2 certified and EMC certified, rated at 80 W, 120 W, 240 W and 480 W (source: TRACO Power)
The HazLoc C1D2 power supply is designed for safe operation in areas that normally contain flammable gases or vapors but may escape in the event of abnormal conditions such as leakage, equipment failure or ventilation system failure.
The most important characteristic of C1D2 equipment is that it will not become a source of ignition under normal and accidental operating conditions. Such equipment shall be designed so as not to emit electrical energy or heat sufficient to ignite a volatile explosive atmosphere. Therefore, such equipment will not generate arc or electric spark during normal operation, and the enclosure structure can limit the entry rate of volatile hazardous substances.
In addition to HazLoc certification, these convector cooled power supplies have an efficiency of 88% to 95% (depending on the model) and can operate at temperatures from - 40 ° C to+60 ° C (full load). Rated power 80 W, 120 W, 240 W and 480 W, output voltage 12 V, 24 V or 48 V, operating voltage 85 VAC to 264 VAC, frequency 50/60 Hz.
TIB-EX series power supply is very suitable for industrial environment, with comprehensive operation protection functions, including output overvoltage and short circuit protection. At the input end, this series of power supply can prevent the voltage drop of the power line, i.e. the voltage drops to less than 90% of the rated value, but it will not be completely disconnected. The typical duration is 3 to 10 cycles or 50 ms to 167 ms. The series of power supplies comply with the SEI F47 Sag Immunity Specification.
The TIB-EX power supply also withstands short-term power overloads and maintains output for up to 4 s at 150% overload. This series is ideal for system designs with stepper motors, solenoid valves, or actuators - loads that generate high current surges at initial energization.
Another common phenomenon in industrial environments is reverse power, where loads such as inductors and reduction motors feed back voltage to the power supply. TIB-EX series power supplies have the important function of power supply backflow protection to help prevent shutdown or failure caused by such loads.
The Switching Mode Power Supply (SMPS) must initially charge its input capacitors, which may result in large inrush currents when the power supply is first connected to the line. Most SMPS power supplies (such as TIB-EX series) use surge current limiters to control this surge current. These supplies are rated for surge currents of 30 A (230 VAC input), 15 A (115 VAC).
All models report output status via DC-OK contact closure and DC-OK LED indicators on the front and side panels.
The 80 W TIB 080-12EX AC/DC DIN rail power supply (Figure 2) has a rated output voltage of 12 V and a maximum current of 6.7 A. The power supply is compact in size 3.71 "x 1.26" x 4.50 mm ".