Reply:To increase the reliability of the power supply, we suggest user to choose a unit that has a rating of 30% more power than actual need. For example, if the system needs a 100W source, we suggest that user choose a 130W power supply or more. By doing this, you can effectively boost the reliability of the power supply in your system. We also need to consider about working ambient temperature of the power supply and whether there is any assistant device for dissipating the heat. If the power supply is working in a high temperature environment, the output power will be derated. The derating curve of "ambient temperature" versus "output power" can be found on our spec sheets. Choosing functions based on your application:
※Protection function: Over Voltage Protection (OVP), Over Temperature Protection (OVP), Over Load Protection (OLP), and etc.
※Application function: Signaling Function (Power Good, Power Fail), Remote Control, Remote Sensing, and etc.
※Special function: Power Factor Correction (PFC), Uninterruptible Power Supply (UPS) function.
Make sure that the model qualifies for the safety standards and EMC regulations you need.
Reply:In general there are two circumstances that will cause the power supply to shut down. The first one is the activation of the over-load-protection (OLP). To deal with this situation, we suggest to increase the rating of the output power or modify the OLP point. The second one is the activation of over-temperature protection (OTP) when the internal temperature reaches the pre-set value. All of these conditions will let the S.P.S. enter protection mode and shut down. After these conditions are removed, the S.P.S. will be back to normal.
2.3V。
Reply:PFC stands for Power Factor Correction. The purpose of PFC is to improve the ratio of apparent power and real power. The power factor is only 0.4~0.6 in non-PFC models. While for PFC models, the power factor can reach above 0.95. The calculation formulas are as below:
Apparent Power=Input Voltage x Input Current (VA) Real Power= Input Voltage x Input Current x Power Factor (W)
From the environmental friendly point, the electric power plant needs to generate a power which is higher than apparent power in order to steadily provide electricity to the market. The real usage of electricity should be defined by real power. Assuming the power factor is 0.5, the power plant needs to produce more than 2VA to satisfy 1W real power. On the contrary, if the power factor is 0.95, the power plant only needs to generate more than 1.06VA to provide 1W real power need. It will be more effective.
Reply:Due to the requirement of EMI, there will be some Y capacitors between line and neutral to the FG (case) to improve EMC. These Y capacitors will cause some leakage current flow from line or neutral to the case (normally case will be connected to earth ground). For example, IEC-60950-1 requires that this current should be less than 3.5mA for IT equipment, so basically the leakage current you find on the case will not hurt human body. Proper connection to Earth ground will solve the leakage current problem.
Reply:During safety verification process, the agency will use a stricter standard -- ±10%(IEC60950 uses +6%, -10%) of the input voltage range labeled on the power supply to conduct the test. So, operating at the wider input voltage range as specified on the spec. sheet should be fine. The narrower range of input voltage labeled on the power supply is to fulfill the test standard of safety regulation and make sure that users insert input voltage correctly.
Reply:Some models control the fan based on internal temperature to extend its life time. For example, the Fan ON temperature for the S-240 series is ≧ 40C (RT1). If the internal temperature does not reach the preset value, the fan will remain still until receiving the start up signal.
