{"id":47,"date":"2021-09-02T02:25:29","date_gmt":"2021-09-02T02:25:29","guid":{"rendered":"https:\/\/www.wehopower.com\/?page_id=47"},"modified":"2025-05-13T15:15:56","modified_gmt":"2025-05-13T07:15:56","slug":"faq","status":"publish","type":"page","link":"https:\/\/www.wehopower.com\/vi\/faq","title":{"rendered":"FAQ"},"content":{"rendered":"
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If you have questions on WEHO\u2019s products, please read the FAQ first. If the listed answers still cannot solve your problems, ease contact us or mail us , We would reply to you as soon as received your request.<\/p>\n

As a dedicated manufacturer of standard power supplies, WEHO provides a wide variety of power supplies to meet different demands from the markets. However, selecting the right products relies heavily on the correct electrical characteristics and specification, we listed the frequently asked questions for your reference.<\/p>\n\n\t\t<\/div>\n\t<\/div>\n<\/div><\/div><\/div><\/div>

1. Q: Is WEHO manufacturer or trading company ?<\/h4><\/i><\/div>

WEHO is manufacturer of power supply for 17 years , from 10w to 18000w .<\/p>\n<\/div><\/div>

2: Q: How Many voltage of output WEHO can supply ?<\/h4><\/i><\/div>

3V 5V 9V 12V 13.8V 15V 18V 24V 27V 36V 48V 60V 70V 72V 90V 110V 150V 220V And so on .<\/p>\n<\/div><\/div>

3: Q: How many the current WEHO can supply ?<\/h4><\/i><\/div>

From 0.5A to 750A (Max power to 18000w )<\/p>\n<\/div><\/div>

4: Q: How to choose a WEHO power supply ?<\/h4><\/i><\/div>

To increase the reliability of the Power supply ,
\nwe suggest users choose a unit that has a rating of 30% more power than actual need.
\nFor example, if the system needs a 100W source, we suggest that users choose a power supply with 130W of output power or more.
\nBy doing this, you can effectively boost the reliability of the power supply in your system.
\nWe also need to consider about ambient temperature of the Power supply and whether there is additional device for dissipating the heat.
\nIf the Power supply is working in a high temperature environment, we need to make some derating to the output power.
\nhe derating curve of \u201cambient temperature\u201d versus \u201coutput power\u201d can be found on our spec sheets.
\nChoosing functions based on your application:
\nProtection function: Over Voltage Protection (OVP), Over Temperature Protection (OVP), Over Load Protection (OLP), and etc.
\nApplication function: Signaling Function (Power Good, Power Fail), Remote Control, Remote Sensing, and etc.
\nSpecial function: Power Factor Correction (PFC), Uninterruptible Power Supply (UPS) function.
\nMake sure that the model qualifies for the safety standards and EMC regulations you need.<\/p>\n<\/div><\/div>

5: Q: What is minimum load requirement and how can I read it from the spec?<\/h4><\/i><\/div>

There are some minimum-load requirements on WEHO\u2019s multi-output power supplies. Please read the specification first before connecting to the load. In order to allow the power supply to work properly, a minimum load for each output is required, or else, the output voltage level will be unstable or outer tolerance range. Please refer to \u201cCurrent range\u201d in the specification as shown in the table below: Channel 1 requires a 2A minimum-load; channel 2 requires 0.5A; Channel 3 requires 0.1A ; Channel 4 does not need any minimum-load.<\/p>\n<\/div><\/div>

6: Q: Why did the power supply shuts down during operation and after turning it off, I can restart the power supply again?<\/h4><\/i><\/div>

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 increasing the rating of the output power or modifying 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.<\/p>\n<\/div><\/div>

7: Q: What is the control mechanism for cooling fans?<\/h4><\/i><\/div>

Cooling fans have a relatively shorter lifetime (typical MTTF, Mean Time To Failure, of around 5000-100000 hours) compared with other components of power supply. As a result, changing operating method of the fans can extend the operation hours. The most common control schemes are shown as below:<\/p>\n

Temperature control: if the internal temperature of a power supply, detected by a temperature sensor, is over the threshold, the fan will start working at full speed, whereas, if the internal temperature is less than the set threshold, the fan will stop working or run at half speed. In addition, cooling fans in some power supplies are controlled by a non-linear control method whereby fan speed can be changed with different internal temperatures synchronously.
\nLoad control: if the loading of a power supply is over the threshold, the fan will start working at full speed, whereas, if the loading is less than the set threshold, the fan will stop working or run at half speed.<\/p>\n<\/div><\/div>

8: Q: What is "Inrush Current"? What will we notice?<\/h4><\/i><\/div>

At input side, there will be (1\/2 ~1 cycle, ex. 1\/120 ~ 1\/60 seconds for 60 Hz AC source) large pulse current (20~100A based on the design of S.P.S.) at the moment of power on and then back to normal rating. This \u201cInrush Current\u201d will appear every time you turn on the power. Although it will not damage the power supply, we suggest not turning the power supply ON\/OFF very quickly within a short time. Besides, if there are several power supplies turning on at the same time, the dispatching system of AC source may shut off and go into protection mode because of the huge inrush current. It is suggested that these power supplies start up one by one or use the remote control function of S.P.S. to turn them on\/off.<\/p>\n<\/div><\/div>

9: Q: What is the difference between -V and COM which are marked on the output side?<\/h4><\/i><\/div>

COM (COMMON) means common ground. Please see below:
\nSingle output: Positive pole (+V), Negative pole (-V)
\nMultiple output (Common ground): Positive pole (+V1, +V2,.), Negative pole (COM)<\/p>\n<\/div><\/div>

10: Q: In WEHO's catalog, we see AC and DC at input, what is it all about?<\/h4><\/i><\/div>

Due to different circuit designs, WEHO power supply\u2019s input consists of three types as below:
\n(VAC\u2252VDC)
\na.85~264VAC;120~370VDC
\nb.176~264VAC;250~370VDC
\nc.85~132VAC\/176~264VAC by Switch; 250~370VDC<\/p>\n

In a and b inputs models, power supply can work properly no matter under AC or DC input. Some models need correct connection of input poles, positive pole connects to AC\/L; negative pole connects to AC\/N. Others may require opposite connection, positive pole to AC\/N; negative pole to AC\/L. If customers make a wrong connection, the power supply will not be broken. You can just reverse the input poles and power supply will still work.
\nIn c input models, please make sure that you switch the 115\/230V input correctly. If the switch is on the 115V side and the real input is 230V, the power supply will be damaged.<\/p>\n<\/div><\/div>

11: Q: What is power good and power fail signals and how can use it?<\/h4><\/i><\/div>

Some power supplies provide a \u201cPower Good\u201d signal when they are turned on, and send out a \u201d Power Fail\u201d signal when they are turned off. This is usually used for monitoring and controlling purpose.
\nPower Good: after the output of a power supply reaches 90% rated voltage, an TTL signal (about 5V) will be sent out within the next 10-500ms.
\nPower Fail: before the output of a power supply is less than 90% rated voltage, the power-good signal will be turned off at least 1ms in advance.<\/p>\n<\/div><\/div>

12: Q: What are the protection forms of overload\/overcurrent?<\/h4><\/i><\/div>

When current drawn exceeds the rating of the PSU, the protection circuit will be triggered to protect the unit against overload\/overcurrent.
\nProtections of overload\/overcurrent can be divided into several forms:
\n(1)FOLDBACK CURRENT LIMITING
\nOutput current decreases about 20% of rated current, shown as curve (a) in the figure below.
\n(2)CONSTANT CURRENT LIMITING
\nOutput current remains at a constant level and within the specified range while the output voltage drops to a lower level, shown as curve (b) in the figure below.
\n(3)OVER POWER LIMITING
\nOutput power remains constant. As output load increases, output voltage decreases in proportion, shown as curve (c) in the figure below.
\n(4)HICCUP CURRENT LIMITING
\nOutput voltage and current keep pulsing ON and OFF repeatedly when protection is activated. The unit automatically recovers when faulty condition is removed.
\n(5)SHUT OFF
\nOutput voltage and current are cut off when output load reaches protection range.
\nNOTE: Protection mode of some of the products combines with different types of the forms mentioned, such as constant current limiting + shut down.<\/p>\n

Recover method:
\n(1)Auto Recovery: PSU recovers automatically after faulty condition is removed.
\n(2)Re-power on: PSU restarts by manual AC re-power on after faulty condition is removed.
\nNote\uff1aPlease do not operate PSU in overcurrent or short-circuit condition for a long period of time to prevent a shorten lifespan or damaging the PSU.<\/p>\n<\/div><\/div>

13: Q: What is the difference between Single Stage and Two Stage Power Supply?<\/h4><\/i><\/div>

There are 2 types of Power Factor Correction circuits; one is Single Stage and the other is Two Stage. Single stage power supply combines functions of power factor correction and converter in one circuit but two stage use two separate circuits. Compared to Single Stage, Two Stage design is more complex and costly but the immunity performance of Two Stage PSU against AC mains is much better than that of Single Stage PSU; in addition, Two Stage manifests better ripple noises performance on output. Owing to that Single Stage is only suitable for fields with quality AC mains but Two Stage can be used in serious circumstance for LED drivers or as industrial switching power supplies.<\/p>\n<\/div><\/div>

14: Q: What application will be the power supply used ?<\/h4><\/i><\/div>

industrial automation control, military equipment
\nscientific research equipment, LED lighting, industrial control equipment
\ncommunication equipment, power equipment, instrumentation, medical equipment
\nsemiconductor refrigeration and heating, air purifier, electronic refrigerator
\nliquid crystal display, LED lamps, communication equipment
\naudio-visual products, security monitoring, LED lamp belt
\ncomputer case, digital products and so on. Instruments and other fields.<\/p>\n<\/div><\/div>

15: Q: How about the quality ?<\/h4><\/i><\/div>

a.Two years warranty for each switching power supply<\/p>\n

b.A strict quality control inspection before shipment<\/p>\n

c. shockproof & high quality blister packing to protect the item from damaging during shipment<\/p>\n<\/div><\/div>

16: Q: The Production Equipment<\/h4><\/i><\/div>

Wave solder machine,Automatic Insertion machine ,High and low temperature heat Chamber, EMI tester Receiver, Leakage current tester ,Comprehensive Performance Tester ,
\nVoltage tester ,Aging Tester ,Resistance Tester, Automatic Double Liquid Glue Machine,Shrink Packaging Machine ,Pachage Tape Machine .<\/p>\n<\/div><\/div>

17: Q: How about the OEM &ODM .<\/h4><\/i><\/div>

ODM design &amp; OEM packing welcome<\/p>\n<\/div><\/div>

18: Q: How about the Lead time .<\/h4><\/i><\/div>

a.MOQ:We support sample order. (1~5 pieces) within 3days<\/p>\n

b.More than 500 pieces ,the lead time is 10-15days<\/p>\n

c. More than 5000 pieces ,The lead time is 22-30days<\/p>\n<\/div><\/div>

19: Q: How about the shipping method ?<\/h4><\/i><\/div>

We usually ship by DHL, UPS, FedEx or TNT. It usually takes 3-5 days to arrive. Airline and sea shipping also optional.<\/p>\n<\/div><\/div>

20: Q: How to Pay?<\/h4><\/i><\/div>

For our customers\u2019 convenience, we accept various payment methods as below:<\/p>\n

PayPal
\nCredit Card (through PayPal or alibaba)
\nWire Transfer (regular Bank transfer)
\nL\/C D\/A D\/P O\/A<\/p>\n<\/div><\/div>

21: Q: Can we be your distributor ?<\/h4><\/i><\/div>

Yes ,if you annuals sales much more than our other customers in your market that you can be our distributor<\/p>\n<\/div><\/div>

22: Q: How to contact you ?<\/h4><\/i><\/div>

Tel:86-577-61777088 Fax:86-577-61777072 Skype:Chnwh005
\nEmail:weho@chnwh.com\u00a0Whatsapp:86-15869492061<\/p>\n<\/div><\/div><\/div><\/div><\/div><\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"If you have questions on WEHO\u2019s products, please read the FAQ first. If the listed answers still cannot solve your problems, ease contact us or mail us , We would reply to you as soon as received your request. As a dedicated manufacturer of standard power supplies, WEHO provides a wide variety of power supplies… Continue reading FAQ<\/span><\/a>","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-faq.php","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"class_list":["post-47","page","type-page","status-publish","hentry","entry"],"acf":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/pages\/47","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/comments?post=47"}],"version-history":[{"count":0,"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/pages\/47\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/media?parent=47"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}