kishore.chander said:
The reason for that is, the extension board may not be able to the required current.
For example, if you go for cheap branded extensions, it would support maximum of just 4 amps... which infers 4*220 volts = 880 watts(Max) its because of the cheap wires used in the extension cord.
There is no difference between a Mainboard and a extension board as long as the wires used are of good quality. For that fact if the main board has a cheap wire connected from your Home Mains... even that will not be able to supply the required amps for the UPS
This may be another reason for that recommendation, but the primary reason is to avoid two surge protection devices in the same circuit, because these days it is hard to find an extension board without surge protection. Plus the UPS manufacturer specifies the input current capacity of the device and appropriate input plug will be used.
If you have an extension box that can handle the required current rating then you should be fine. It is upto the user to ensure this. Plus most of the decent extension boxes have a fuse that is rated at the max current carrying capacity of the device. If there is excess current flowing the fuse will blow. Talking about inadequate wiring, even a 15A socket can be wired with wiring that cannot handle even 5A. This is usually not the case. Electricians make sure proper guage wire is used when wiring the house. Otherwise there is a risk of wires burining, resulting in fire.
It is not always adviced to go for the highest amp socket (like 15A), if the load does not require that much current. These sockets are usually connected to higher amp circuit breakers. So if there is a sudden increase in current flow because of a short-circuit, brown-out etc. the circut breakers allow more current (15A) to pass through before tripping resulting in a potential damage to the load. If the load has appropriate fuses or OCP then it may be saved. For example if u have a load which draws a max of 5A then it not advisable to connect it to 15A socket.
So based on the load, the user has to determine which socket has to be used. Let us take an average user like emperor and calculate his systems power consumption.
In the case of emperor he said that he was using the same extension board to power his computer before he bought the UPS. So I assume it should be sufficient to handle the load. Now if we calculate the load he is going to connect to the board.
1. His ups is a 550 VA, max load that it can support is less than 400w. He connects his PC with the monitor to the UPS. If the load connected to the UPS exceeds the limit it can handle it will give overload indication (APC UPSs have this feature, continuous beep with red LED indication). I assume this is not happening in his case.
2. If you consider rest of the equipment like modem, router, they consume very less power. It wont be more than 50w.
3. The last thing to consider is his speaker system. If its a normal 2.1 speaker system it will consume less than 100w. Emperor which speaker system are you using?
Emperor please correct if any of the above assumptions are wrong.
Now total load = 400 + 50 + 100 = 550w
Max current drawn = 550/220 = 2.5 A
If you calculate the max load a 6A socket can handle, it is = 220*6 = 1320w. To be on the safe side lets say 1000w. If your load is anywhere less than this a 6A socket should do (assuming the electrical wiring is adequate). Which is the typical scenario and most computer setups fall in this category.
If a users setup requires more than 1000w then he should think of going for a higher amp socket.
So too much is not always good. Use the appropriate socket and extension board that can handle the load.
satyanjoy said:
@kishore.chander: thanks for names - i will look for any of this cables. Can I change the current mainboard to a 16amp without changing wireing
@satyanjoy, Calculate you load power consumption. If your load is less than 1000w then a 6A socket is more than enough. If your extension box can handle this much current then the box also should be fine. You can check the brand and rating of the wire used in your extension board. The brands that kishore.chander recommended are good.
