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Hi, I intend to use stainless steel wire instead of copper as grounding conductor. I understand that copper is a far better conductor than steel. Is there any regulation which prohibit the use of stainless stell as earthing conductor? Thanks for any advice. Grundig

Thanks for the replies. Keith, I will try to get pictures. Yes, the panel was meggered @ 1000 V before energising. Grundig

Hi, Help forum forum members ! We are having intermittent phase to phase fault on a distribution panel @ 590 V. We could see trace of arcing between the phases on the incoming circuit breaker feeding the common bus in the panel. The circuit breaker was replaced. Before energising, the...

Ok. Sorry for the misunderstanding. Let me clarify the issue. The transformer 22 k V start point is grounded through a potential transformer, which rating is 13k V /110 V. I believe this transformer should have been sized to the V_LL. Grundig

Hi, Thanks for the replies. The 22 k V transformer is grounded through this PT that is the PT is connected to the star point of the 22 k V transformer. I understand that the fault current should be high enough to induce a voltage in the secondary. But my understanding is that this PT should be...

Hi, I visited a site where they used a potential transformer to sense ground fault on their 22 kV / 400 V transformer. The PT is rated at 13 k V/ 110 V . This sound strange as the PT should have been sized at the rated line/line voltage of the transformer. Any comment ! Grundig

Hi, I have seen many installations where the star point of MV alternators are high impedance grounded. There are nothing uncommon with these practices and they are done almost all the times. What is uncommon is that when the alternator is not in service, the network works ungrounded. I just...

Thanks all for the prompt replies. The intention of using high impedance grounding is to limit the magnitude of fault current to a safe value. Grundig

Hi, I`m looking for guidelines on how to measure the capacitive charging current on a 400 V 3500 kVA system.The intention is to limit the ground fault current close to the capacitive charging current. Thanks. Grundig

Hi, In the SDS of Sulphur dioxide gas, it is mentioned that the critical temperture of S02 gas is 175 deg C. We used to operate ou process regularly with SO2 gas well above 200 deg C.Basically, what does the critical temperature menas? Thanks for your respeonses. Grundig

Hi, Thanks for the replies. I should perhaps have said turbo-compressor. Grundig

Hi, First of all,please bear with me as I`m not a turbodynamic guy. I `m rather an electrical one. I will introduce the picture of the situation.I work in a dyeing factory located close to a power generation plant. We have a contract with the plant and the power plant supplies us with...

Dear all, I did infra red inspection on the transformer bushings and nothing abnormal were found. The connections to the panel were checked physically and found tight. We could not do infra red inspection on the terminal connections as the inspection guy was scarced to do the test with the...

GHi, I did an infra red inspection on one 6,6 k V 3 cores XLPE Cable entering my 6,6 k V panel. There is nothing wrong on the terminal connections to the panel and nothing wrong either on the transformer terminals connection. The inspection is showing that part of the cable is heating as shown...

Hi, Thanks all for the inputs. The motor data are correctly entered. It is also worth mentioning that the previous drive was a variable torque one. I am in touch with the ABB people and shall keep all informed. Thanks again. Grundig

Yes, the ID Run was performed as instructed in the manual. In any case, the drive is configured as ID Mag that is each time a start command is given, the drive will magnetise the motor to develop the model. Grundig

Hi, I just installed one 1500 A ACS800 drive. It`s running on DTC control mode and the motor is drawing excessive current at half nominal speed. Another drive of different make hardly drew 60 % nominal current at that particular speed. The ACS drive drew around nominal current at that speed. I...

To complement davidbeach`s post,zero sequence currents cannot flow in the lines connected to a delta connected winding because no return path is available for these zero sequence currents.However, the zero sequence currents, caused by the presence of zero sequence voltages,can circulate through...

Hi, I am actually designing one 11 k V distribution switchboard for a factory. The national grid feeds at 22 k V. There is one 10 MVA 22/11 k V Yd11 transformer, rather new and in very good condition,and the management is pushing to use this transformer. The 11 k V distribution will feed four...

Thanks electricpete for your comments. I perused through EPRI docs and have come across a document about maintenance scheduling for large motors and they quote physical inspection of the stator winding and core every one and a half year. Could we inspect stator winding and core without...