ARCH Frequently Asked Questions | ARCH ELECTRONICS CORP.
Certified Solutions for Industrial, Medical, and Smart Grid Applications. Founded in 1986 and headquartered in Taiwan, ARCH Electronics Corp. is a trusted manufacturer of compact, energy-efficient AC-DC power modules, DC-DC converters, and medical-grade power supplies. With in-house production and full ISO 9001, CE, UL, and TUV certifications, ARCH offers high-reliability solutions for industrial automation, telecommunications, energy storage, smart grids, and healthcare equipment. Our product range includes models with wide temperature tolerance, reinforced 4000VAC isolation, 2 x MOPP medical compliance, EMC Class B certification, and ultra-low no-load power consumption. ARCH supports global customers with OEM/ODM customization, and continues to innovate through its R&D to deliver performance-driven, environmentally sustainable power solutions that meet the latest safety and industry standards.
FAQ
When selecting a power supply, it's common to encounter technical questions or specific application concerns. To help you better understand ARCH's product naming conventions, model selection guidelines, safety certifications, and usage precautions, we’ve compiled a comprehensive FAQ section. These FAQs cover a range of essential topics-from how to choose the right power module, minimum load requirements, and inrush current behavior, to EMC compliance and the differences between industrial and medical safety standards. Whether you're new to power supply selection or facing system integration challenges, the answers below provide practical insights to support your decisions.
How do I choose the models?
In general the models and naming are as below, please refer to each models datasheet for details.
| Series Name | Output Voltage & Output Type | Option for Screw Terminal | |
| AOCH10 | 5 | S | A2 |
| AC-DC ITE, Household, Switching Power start with A For instance: AOCH10, ARF500 | 5 = 5W | Single = S 5S | A2 |
| AC-DC Medical, Medical switiching start with M For instance: MQF, MTC, MFC | Dual = D 5D or 5S12S | ||
| DC-DC starts with S or Z For instance: SW, ST, ZB, ZC | Triple = *S*D 5S12D | ||
Notes on selecting a power supply.
1. When using the power supply, the working temperature is defined as of it is measured from 1 cm next to power supply and shall be derated if working on a higher temperature environment. Please refer to the product datasheet for the derating curve of the temperature versus output power.
2. It is suggested to choose a power with a rating of 30% more power than the system actual needs, in order to increase the reliability of the power supply. For instance, if a system needs a 100W source, please consider 130W or higher. It can effectively improve the reliability of the power supply in the system.
3. Choose Function for your application
Protection Function: Over Temperature Protection (OTP), Over Voltage Protection (OVP), Over Load Protection (OLP), etc.
Application Function: Signaling Function (POWER GOOD, POWER FAIL), Remote Control, Remote Sensing, Parallel connect, etc.
Special Function: Power Factor Correction (PFC).
4. Make sure the selected model to be qualified with the required safety standards and EMC regulations.
Can ARCH power supply be using in the frequency range of 45 ~ 440HZ? If yes, what is the impact?
In general ARCH power supply can be used in this frequency range, however, if the frequency is too low that may decrease the efficiency and the PF value. In addition, if the frequency raises up, the leakage current will increase.
Will minimum load be required to ARCH power supply?
The design and its application of each power supply is different, some of ARCH’s power supply will require minimum load, for the details please refer to the minimum load value in the datasheet.
Why power supply shut down during operation?
In general, it could be that
1) overloading causing the Over Load Protection (OLP) to be activated, suggest to increase the rating of the output of the power or modify the OLP point.
2) overtemperature causing the activation of the over temperature protection (OTP). Suggest to choose the power supply based on required ambient temperature and rating.
What is inrush current? What to pay attention to?
There will be a large pulse current (depending on the design, it is about 20 ~ 100A, refer to the product specification) at the moment when turning on the power. It will be normal rating after system is on. It may happen regularly at the moment when turning on, it is normal and will not damage the power supply. However, it is not recommended to switch on/off the power supply constantly. Please note, if need to switch on multiple power supplies, suggest to switch on one by one and not all at the same time.
What is differential between MTBF & Life Cycle?
MTBF and Life Cycle both are common indicators of product reliability. We follow the standard of MIL-HDBK-217F Notice 2 (Stress Analysis) as the calculation base for MTBF. MTBF (Mean Time Between Failure) is the expected value of reliability prediction, which refers to the average time when the reliability of the power supply drops to 36.8% after continuous operation for a period of time.
Life Cycle refers to the result of the temperature rise test of the capacitors and electrolysis at maximum operating temperature, to calculate the reference life time of the capacitors, electrolysis and the power supply.
The case seems to be charged, is it normal?
Due to the requirements of EMI, the input of the power supply may connect to the FG (case) through the Y capacitors. This may cause the case to be charged. That's the reason for a clear definition of the leakage current value defined in IEC / UL / EN safety regulation. ARCH power supply is certified with these safety regulations, this will be solved when the power supply is connected to the ground properly.
ARCH power supply has CE marketing, when install in customer's application, will it meet EMC requirement for sure?
Under different environment and application, the EMC test result may be different, once the power supply is installed in customer’s application, ARCH couldn’t guarantee that the final system will meet the EMC requirement automatically. The test result we provided is based on the power supply stand alone.
Is any different between Information (EN60950-1) and Medical (EN60601-1) Safety standard?
According to the Safety standard, the leakage current in EN60950-1 Class I cannot exceed 3.5mA; in EN60601-1 the leakage current cannot exceed 300uA. The safe distance and numbers of fuse are also different when measuring.
| Subject | IEC60950-1 | IEC60601-1 | ||
| Creepage Distance / Clearance Distance | Basic Insulation ≥ | 2.5mm / 2 mm | 4mm / 2.5 mm | |
| Working Voltage: 250 Vrms (Max.) | Supplementary Insulation ≥ | 5mm / 4mm | 8mm / 5mm | |
| Electric Strength Test | Basic Insulation ≥ | 1500 VAC | 1500 VAC | |
| Supplementary Insulation ≥ | 3000 VAC | 4000 VAC | ||
| Leakage Current | Class Ⅰ≤ | Handheld type 0.75m A | - | |
| other 3.5 mA | Leakage current of ground | 300µA | ||
| Leakage current of case | 100µA | |||
| Class Ⅱ ≤ | 250µA | Leakage current of case | 100µA | |
| Number of Fuse | Class Ⅰ | Lx1 | Lx1 Nx1 | |
| Class Ⅱ | Lx1 | |||
| Operating Temperature | By manufacture defined | ≥ 40 °C | ||
ARCH Introduction
ARCH ELECTRONICS CORP. is Taiwan supplier and manufacturer in Other Electronic Components Manufacturing Industry. ARCH has been offering our customers high quality AC-DC power module, AC-DC Encapsulated Power Module, AC-DC switching power supply, PCB Mount AC-DC Power Module, PCB mount AC-DC encapsulated power module, Semi-Potted AC-DC Switching Power Supply, Ultra-Compact AC-DC Power Module since 1986. With both advanced technology and 20 years experience, ARCH always make sure to meet each customer's demand.
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