Thursday, July 8, 2010

Temperory circuit..

currently we are using this circiut for temperory lighting control using photocell..

Saturday, July 3, 2010















Transformer,Distribution panel & Local Control Panel all located in same location..only master control panel located 3 kms away...


from the transformer -- > distribution panel MCCB breaker(40A)-- >contactor in the local control panel
the load(LIGHT) is connected with the contactor(as mentioned in single line diagram)..
contactor is normally open..
In H-O-A when we switch to H then the contactor coil enerzise then it become closed..
then the power is supplied to load..
when we make in AUTO it check the photocell, the photocell NC in night, at night the supply goes to contactor coil and it enerzises and become NC.. then the supply goes to light..
my doubt
1) when we supply the power from the master control panel is it enough to close the relay contact (CR1 & CR2) which is located in local control panel..
2)how much voltage required 277 v relay to close its contact?
3)according to the calculation we get around 240 or 235 at the receving end after the voltage drop.. can we use 240v relay?

single line diagram














..



here power from the transformer --> distribution panel --> local control panel --> master control panel..
1) i have doubt wheather this circuit works or not?
2)from the local control panel to master control panel.. the distance is nearly 3000m
(3 KMS), if suppose the relay is placed in the local control panel, we applied the voltage from the master control panel, it is enough for relay to change its contact..
3)we want to use pilot lamps for indication, wether pilot lamps receive enough voltage and current form the local control panel to master control panel for its consumption(voltage drop?)