Question { 3459 }

my question is that....few days ago i had installed a three
phase motor starter for an electric saw.the motor will run
and make the hydraulic pressure which will be goes to
pressure cylender by up and down lever.two number of
limitswitches are also installed on cylinder for safety of
motor.now when the arm of cylinder reaches to the upper or
lower limit it will cut the motor's line.and motor will be
stop.now wana know that what will i do that motor runs
continue after the limitswitch cut it down but it shold not
be made any pressure.pls answer me in brief.

Answer

There should be some way to vent the excess pressure built by the motor. So first of all you should have a pressure gauge or sensor to read the pressure. Then you should have either a re-circulation line in the system or vent valve to channel the excessive pressure. When the hydraulic pressure reaches a set limit the re-circulation valve should open and channel the excessive pressure back to the tank/reservoir. In this way you can keep the motor constantly on without causing damage to system.

Question { International Mega Food Park Limited, 5502 }

what's interlock relay ?

Answer

Interlock relay is a type of protection system which senses some event and triggers corresponding action.
For example, NC relay for power supply will keep the supply up normally, but as soon as some fault occurs, it will change to OPEN contact and cut the power supply to the system. This action is called interlock and therefore the relay is named interlock relay

Question { Ankit Metal Power, 3472 }

Why in turbine used two critical speed band ?

Answer

This depends on the design of the turbine. I worked with turbine with 4 critical speed bands. It is the natural harmonic frequency where there is maximum vibrations in the turbine. These speed bands can be more than one. Length, weight and steam entry type are the factors which decide the critical speed bands in a turbine.

Question { 5302 }

if suppose boiler has high heavy tube leakage, so in which time we feed the water in a boiler. can we stop the feed water at particular combustion temperature.

Answer

Hi,
I am assuming you want to stop the feed water to attend the tube leakage. But it is not clear what the question is about. IF the light up has been done,I do not think the flow of the water in boiler can b stopped. Secondly if light up has not been done then better to shut down the unit and properly take up tube leakage attending procedure.