mbensema I measure the temperature with RTD, the motor is greased. Unfortunately i dont have motor catalogue either bearing manufacturer.
Can you rpopose trip limit for dip groove ball bearing?
Hello to all. On site we have a 6.3kV motor with Drive end bearing D625-6322-C3. On this bearing we experience temperatures to 61 oC. Is this normal wroking temperature? The protection relay of the motor trips at 70 oC. I think this is a little bit more sensitve than usuall. In other...
Hello to all. On site we have a 6.3kV motor with Drive end bearing D625-6322-C3. On this bearing we experience temperatures to 61 oC. Is this normal wroking temperature? The protection relay of the motor trips at 70 oC. I think this is a little bit more sensitve than usuall. In other...
On site we have two cast resin transformers 2MVA running at loads between 50-60% of nominal rating. The air temperature during summer period exceeds the value of 40 oC and sometimes reached 45 oC. The transformers are cooled with natural circulation of air from air holes on the bottom and air...
hi rmw and thanks for the answer. We noticed exactly what you say . In winter time TK fans absorb higher amps than in summer time. About the pressure i dont have specific measurement. But we have noticed that the machine hall has underpressure in comparison with the external environment and as a...
On site we have a Gas Turbine GE 9FA DLNII. The exhasut frame of thegas turbine is cooled with inlet of air via the TK fans, exhasut frame blowers TK-1 and TK-2. What we have seens until now is the motors working to nominal current, the diverter flap stucking in the middle position. These fans...
Dear all
On site we have one Ge generator 325MVA 4-pole hydrogen cooled with static excitation system EX2100. One of the features of the excitation system is the Power System Stabilizer. Unfortunately this is not tuned yet. Is it possible to tell me some more theoretical or practical data fro...
Hi ters. The turbine mechanical parts will start overheating. Also the generator will draw big amount of reactive power. This is the reason that if the generator circut breaker fails then thne Circuit breaker function shoulf trip the overhead breaker, on the grid.
Also there should be thrust...
Hi bacon, thanks for the pic.
It seems that the corona rings are towards the insulators strings and not towards the active line as it happens on our site.
HI Scotty and thanks for the pdf. n our plant the rings are not installed at the Step Up transformer bushing but on the tension insulators. he question is if they rings should be on the live part or upon the tension insulator. From what i read on the NGC pdf they rings should be installaed in...
Dear all. I want to place my question about the installation of arching rings on 400kV overhead lines. These rings are supposed to carry any transient overvoltage and try to break the air gap so they should be placed in the lower length between the live terminal and the earth. Can you give some...
subtech The generator nominal apparent power is 324MVA and the power used to start the generator is maximum 11MVA.
rraghunath Thanks once again for the detailed justification.
The gas turbine is a GE 9FA DLN II with a generator coupled and the GT is started not by a prime mover (another generator) but as a motor supplied with variable frequency and voltage through a frequency converter (GE LCI).
Dear all. On site we ahve a GT generator that is started by means of a static starter (LCI load commutated inverter). At this moment the neutral (star point of generator) is isolated from ground by a disconnector. When GT reaches full speed no load (FSNL) then the neutral disconnector closes and...
Dear all. On site we have a 400kV circuit breaker that connects our step-Up transformer high voltage to the grid substation.
The poles of the circuit breaker have in parallel connection capacitors.
Can you explain why these capacitors are installed?
I guess they are used for precharging of the...
Dear all, my main concern is not if i open first the breaker and then the disconnector, i know that. My concern is when i open the circuit breaker if i have to open immediately the disconnector (in a period of 10 sec) as per manufacturer recommendation.
Dear all. On iste we have a three winding step-up transformer connceted to the grid of 400kV via a disconnector and a circuit breaker. The disconnector is between Step-Up transformer and circuit breaker. When we de-energize from the 400kV grid we are instructed to open first the circuit breaker...
Hello to all. I want to ask if you can suggest a vendor with portable earthing devices for 400kV substations. Take in mind that our plant is located in Greece. Here i find it very difficult to locate one.
