Hello I imagine such a circuit. I have a 5 amper circuit ad a 50 volt source voltage and this circuit feeds only a coil which lifts say a certain weight . Now what I wonder is what happens if I let the weight drop using my hand. Does the current keep on being 5 amper again or it decreases?
Hello, I want to ask you about a system in which there are three transformers and 3 gensets all have the same KVA respectively, I mean the back-up gensets are rated the same KVA with the tranformer to which they belong, Of course xformer-genset groups have different power ratings from each other...
Hello, I wonder if paralleling UPS's requires continuity of neutral all the time, ?t was said to me that with busbar feeding of n+1 ups operation caused problems (I dont know the details to much) since busbar breakers was breaking neutral of the ups'es . So I ask you if there is such a situation...
Hi, I am hesitating in this issue (POWER FACTOR CONNECT?ON CAPAC?TORS' L?NE PROTECT?VE FUSE RAT?NG )since I am not sure to which criteria we must select the fuses. I mean must we use a motor fuse since the in rush current makes necessary that a delaying type fuse is used. If this is so for...
Hi, I want to learn about the design of harmonic filters. I read through some info about it but unfortunately I could not get the logic of the sizing of the filter. Say I have a system dominated by 7. harmonic current. I want to learn two things.
Firstly, is there any relation between the...
Hello ,I wonder how these two operate together? They operate parallel or a in a different way? I did not see any example of this till now. Please tell me about this roughly...
hi, we use Phase+neutral breaking MCB in isolated neutral systems. I wonder one thing.
For a 120 volt say 6 A circuit is switched by 6 A MCB
so for a 120 volt 6 A circuit ?solated neutral circuit if mcb is rated 6 amper it means it has two contacts of which each has the same capacity of the...
Hi, Can you tell me how can a parallel capacitor added to the control circuit lessen the effect of a high-residual-voltage occuring due to line-line capacitance here. I know that added capacitor means a higher total capacitor and it will create a bigger voltage and a longer time duration...
Hi, I wonder how is the DC bar of an online ups can be kept constant? I mean if your utility voltage is fluctuating in a wide range, so it means your DC voltage rectified on DC busbar will behave also so isnt it? I guess to be able to chop the voltage on this bar it is needed that this voltage...
Hello, I wonder if there is a relation between the power of a transformer and turn number of its spins? if so how can be determined the turn number of a xformer of any power ?
Hello friends, I wonder if there are guys here who have information about IEC standards of insulated power systems. How can a firm declare itself as complying with the requirements of IEC standarts ? Accredited labs for example? In european countries or in USA how a firm can prove that its...
Hi,I saw in a specification booklet of a 154 kV circuit breaker a clause which calls for a" phase disagreement protection " in the 154 kV circuit breaker, first can there be an integral protection scheme or must be it a separate relay in the control box of this circuit breaker? ?f so there is...
Hi, I wonder if two pole circuit breaker has half times the short circuit breaking capacity of single pole circuit breaker? since as we increase the poles on the circuit it means less voltage on the contacts and from there on can we say circuit breaker s.c capacity is inversely proportional to...
