36V 9.7A Power Supply LRS-350-36 350W

Detailed Product Review

The LRS-350-36 model 36 Volt 9.7 Amp Power Supply, offered by Mermak CNC, is a high-performance switching mode power supply (SMPS) unit designed to convert alternating current (AC) to stable direct current (DC) for industrial automation systems and various machine applications. This device is capable of operating within a wide AC input voltage range (typically 90-264 VAC). Through its internal stages of rectification, filtering, high-frequency switching (with PWM control), transformer isolation, and secondary rectification/filtering, it provides a nominal output voltage of 36 VDC with a continuous current capability of up to 9.7 Amps, offering a total power capacity of 350 Watts. The high switching frequency minimizes power loss, while the integrated feedback loop ensures excellent regulation against load and line fluctuations, guaranteeing a stable energy supply critical for connected equipment. This design ensures low ripple and noise levels, essential for the reliable operation of sensitive electronic components and motor drives.

The structural components of the LRS-350-36 power supply are selected to withstand demanding industrial conditions. The unit’s external casing features a perforated metal structure to support passive cooling, and its internal PCB (Printed Circuit Board) houses high-quality electrolytic capacitors, switching transistors (MOSFET or IGBT), inductors, and control integrated circuits. This component selection ensures long-lasting and reliable operational performance. For system integration, AC input (L, N, FG) and DC output connections (V+, V-) can be easily made via standard screw terminal blocks. Its compact dimensions and industrial-standard mounting holes allow for easy installation into control panels, machine frames, or onto rail systems using DIN rail adapters (available separately). This power supply is utilized as a reliable energy supply solution in a wide range of industrial automation and machine manufacturing applications, including CNC machines, industrial robotic systems, PLC control units, servo and stepper motor drivers, LED lighting fixtures, test and measurement equipment, and telecommunication infrastructure.

High Conversion Efficiency and Thermal Optimization: The LRS-350-36 power supply offers a conversion efficiency exceeding 85%, transforming a significant portion of AC mains energy into usable DC power, thereby minimizing energy losses. High efficiency directly reduces internal heat generation within the power supply, which lowers thermal stress on components, extends their lifespan, and alleviates cooling requirements. The unit’s perforated metal casing provides effective passive cooling through natural convection, eliminating the need for additional fans or complex thermal management systems and reducing the overall noise level of the system. This thermal optimization allows the power supply to perform reliably across a wide operating temperature range (typically -20°C to +70°C), although output power derating may apply at higher temperatures.

Comprehensive Integrated Protection Mechanisms: This power supply features various integrated protection functions to ensure the safety of connected systems and its own components. Over Voltage Protection (OVP) prevents damage to sensitive loads by stopping the output voltage from exceeding a set threshold. Over Current Protection (OCP) protects the power supply when the output current exceeds its nominal value, typically implemented through constant current limiting or a “hiccup” mode. Short Circuit Protection (SCP) quickly activates in the event of a short circuit at the output terminals, safeguarding both the power supply and the wiring system from overcurrent damage. Additionally, Over Temperature Protection (OTP) is included; this ensures the unit automatically shuts down when internal temperatures reach critical levels, preventing thermal damage. These protection mechanisms maximize system reliability and operational continuity in industrial applications.

Industrial Standardization and Easy Integration: The LRS-350-36 power supply is designed in compliance with safety and electromagnetic compatibility (EMC) standards widely accepted in the industrial automation and machine manufacturing sectors. This compliance ensures the product can be used seamlessly in different geographical regions and various industrial environments. Its compact form factor and standardized mounting holes offer space efficiency in control panels and equipment enclosures. Screw terminal blocks allow for reliable and easy cable connections, while clear labeling minimizes installation errors. These features enable engineers and technicians to integrate the power supply quickly and efficiently into existing or newly designed systems, reducing installation time and costs while enhancing overall system reliability. Its modular structure also simplifies maintenance and service operations. Mermak CNC proudly supplies these units to customers in the United Kingdom, United States, Canada, Australia, Ireland, New Zealand, South Africa, and similar international markets, ensuring global availability and support.

Technical Specifications and Capacity

Technical Frequently Asked Questions (FAQ)

Is it possible to increase the capacity of this power supply through parallel or series connection, and what technical considerations are important for such configurations?

Standard industrial power supplies like the LRS-350-36 are generally optimized for single-unit operation. Increasing output current via parallel connection typically requires power supplies to have specific “current sharing” features, which ensure each unit distributes current equally to the load. As the LRS series models do not possess this feature, direct parallel connection can lead to unbalanced load distribution among units, overheating, and consequently, premature failure. If parallel connection is unavoidable, current balancing can be achieved by adding a low-value, high-power resistor in series with the output of each power supply, but this method results in efficiency loss. Increasing output voltage via series connection is technically feasible, but factors such as the output isolation voltage limits of each power supply and the potential formation of common ground loops must be carefully evaluated. Generally, for series connection, it is recommended that power supplies are specifically designed for this purpose or that external isolation modules are used. In both scenarios, the manufacturer’s specifications and application notes must be strictly consulted.

What are the thermal performance and cooling requirements of the power supply? What performance can be expected at high ambient temperatures?

The LRS-350-36 power supply operates on the principle of natural convection cooling through its perforated metal casing. This means heat generated by internal components is transferred to the surrounding air without any active fan mechanism. For optimal thermal performance, ensuring adequate airflow around the power supply is critical. When mounting within a control panel, it is recommended to leave at least 10-15 cm of clearance above and below the unit, and at least 5 cm on the sides. Ambient temperature is one of the most significant factors directly affecting the power supply’s lifespan and performance. While the product’s operating temperature range is typically stated as -20°C to +70°C, “derating” (capacity reduction) of the output power is applied at ambient temperatures above +50°C. For instance, at +60°C, the output power may need to be reduced to 75% of nominal, and at +70°C, to 50%. This is a safety mechanism designed to prevent the power supply from overheating and component failure. To operate at full load under high-temperature conditions, forced air cooling (using a fan) or operating with a reduced load may become technically necessary.

What is the tolerance of this power supply to input voltage fluctuations, and how does this affect output stability?

The LRS-350-36 model has the capability to operate within a wide universal input voltage range from 90 VAC to 264 VAC. This broad range provides high tolerance to mains voltage fluctuations or standard voltage levels in different geographical regions. Due to the nature of Switching Mode Power Supplies (SMPS), the internal feedback loop actively compensates for variations in input voltage. Consequently, even if the input voltage fluctuates within the nominal range, the output voltage (36 VDC) is regulated with extreme stability. This characteristic is known as “line regulation,” and for the LRS-350-36, it is typically below 0.5%. Input voltage fluctuations can also affect the output ripple and noise levels, but the power supply’s internal filtering circuits are designed to keep these effects below the specified maximum level of 150mVp-p. This ensures that connected electronic devices are supplied with clean and stable DC power, independent of mains conditions.

How do the overload and short-circuit protection mechanisms of the LRS-350-36 model work, and what is their contribution to system safety?

The LRS-350-36 power supply is equipped with Over Current Protection (OCP) and Short Circuit Protection (SCP) mechanisms. In an overload situation, meaning when the current drawn by the connected load exceeds the nominal 9.7 Amp value, the power supply typically enters a protection mode known as “constant current limiting” or “hiccup mode.” In constant current limiting mode, the output current is maintained at a specific level while the output voltage drops. In hiccup mode, the power supply periodically attempts to supply the load by switching on and off, and automatically resumes normal operation once the overload condition is removed. Short circuit protection activates when a direct short circuit occurs at the output terminals and usually operates in hiccup mode or a complete shutdown (latch-off). These protection mechanisms prevent damage to the internal components of the power supply (transistors, diodes, etc.) due to overcurrent and overheating, while also protecting the connected loads, wiring, and the overall system from electrical faults. This significantly enhances operational safety and equipment lifespan in industrial environments.