News center-QianEn Tech Co.,Ltd.

Add：2nd Floor, No. 3 North Third Street, Hadi Daxin Road, Nancheng Street, Dongguan City, Guangdong Province

News centerNews center

Notes on choosing a switching power supply?2020-08-17: To increase the reliability of the S.P.S., we suggest users 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 users choose a S.P.S. with 130W of output power or more. By doing this, you can effectively boost the reliability of the S.P.S. in your system.

Can MEAN WELL charger use on Lithium battery or other type of battery?2020-08-17: All MW chargers are designed for lead-acid batteries. Every Lithium battery or other type of battery will have its own charging/discharging characteristic. Modification will be required for MWs charger in order to match the profile of each battery or users requirements. Please contact your local distributor if you would like to have a modification for your own battery.

What should be noticed when installing a power supply in vertical and horizontal directions?2020-08-17: Most small wattage and fanless power supplies are mainly installed in the horizontal position. If you have to install it vertically because of mechanical limitation, you should consider the output derating due to the heat concern. The temperature derating curve can be found on the spec sheet. Regarding the power supplies with built-in fan or the application has forced cooling system, vertical and horizontal installations have less difference. Ex. In SP-150 derating curve, the ambient temperature difference in application is 5 Celsius from vertical to horizontal. The output wattage in forced cooling can be 20％ higher than air cooling convection.

For certain need, is it possible to reduce the noise of fan?2020-08-17: Noise is directly related to the fan which is build into the power supply. Lowering the airflow of the fan means reducing the heat dissipation ability. It will also influence the reliability of the products. Furthermore, minimum airflow of fans is defined by Safety Organization and a safety appendage will be needed if using a new fan. If fan noise is a critical concern, we suggest to select FANLESS products or contact MEAN WELL for other possibilities according to the conditions of use.

During the operation of your power supply, there is some leakage current on the case. Is this normal? Will this leakage current hurt human body?2020-08-17: 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.

The output ground (GND) and frame ground (FG) is the same point in my system, can MEAN WELL's power supplies be used in such system?2020-08-17: Yes. Since our products are designed based on isolation concept, it will be no problem that the output ground (GND) and frame ground (FG) is the same point in your system. But, EMI may be affect by this connection.

Why I can not turn on the power supply smoothly when the loads are motors, light bulbs or capacitive loads?2020-08-17: If you connect the S.P.S. to motors, light bulbs, or high capacitive loads, you will have a high output surge current when you turn on the S.P.S. and this high surge current will cause failure of start up. We suggest using S.P.S. with constant current limiting protection to deal with these loads.

Requirements on parallel operation？2020-08-17: When power supplies are connected in parallel, it is able to increase the output current or use them as the redundant (back-up) function. Be sure that the difference in output voltage and wiring impedance should be small when operating in parallel.