Example : a small turbine with a single phase 240 volts 50 Hz synchronous generator. The output power of the 0.8 pf generator is 5 kW. The turbine set is installed very close to the house. What extra switchgear will he require to use the turbine. a).if the main power supply is removed completely b) if the intends to keep and use the main power during dry periods?
Fig.1
The kVA rating of the generator is 5kw/0.8 = 6.25 kVA. The current of the generator is 6.25 kVA/240 V = 26 amps. So all his new switches should be 30 amps.
a. If the mains power is removed completely, he an connect the hydro power to the existing main switch and use it as it is. If no ELCB is available he can have that as an extra. See fig 1
Fig 2
If he want to install trips eg under-volts, frequency etc, he needs a 30 amp contactor with coil voltage of 240 volts. This contactor can be as shown below. See fig 2
b. If he want to keep the mains supply along with the hydro supply he needs a manual changeover of 30 amps rating, and also a 30 amp main switch. If he hopesto use trips then he requires a contactor as mentioned above. See fig 3.
Fig 3
No comments:
Post a Comment