Is this a new transformer installation or it is an existing transformer which was taken out of service for maintenance or a power shutdown?
If the unit was a new installation, was electrical testing, oil sample, inspection, and test of all auxiliary devices performed? Stardard commissioning...
Although the equipment has operated 30+ years event free, the condition of the equipment is not as it was new. The condition of the equipment is dependant on the maintenance history, environment and number of operations.
We perform routine maintenance on the sort of equipment you describe...
I believe this is an old oil dashpot equipped breaker. These are obsolete nowadays and are typically replaced with new solid state relay and current sensors.
When performing maintenance testing on oil filled equipment normally dissipation or power factor testing is performed. I have seen a correlation between between lower insulation resistance and greater dissipation factor readings on smalled oil filled equipment below 25kV and less than 2MVA...
I have performed dielectric withstand tests in the past in 69kV substations because it was required by the project engineer.
We performed the tests to NETA specifications. We used a stackable highpot. I believe we performed the test to approximately 120kV. The test only included some...
Does anyone have any comments regarding how far out to take the remote current electrode when performing the fall of potential test....Do I treat the ground grid as 100m or 700m when connected to the pen stock?
We are using the same Omicron equipment for our testing. Due to the terrain we will likely not be able to accomplish 90 degrees between the potential and current wires.
We could measure the mutual coupling of the overhead line with the Omicron equipment and take this into account to evaluate...
I am not certain on the length of shield wire at the moment but I do know it only extends a few towers out from the substation. This is regular practice for BC Hydro tranmission lines.
At this point I would have to have discussion with the engineer and utility to determine feasibility of...
On an upcoming project we are required to measure the ground grid impedance of a ground grid installation for an outdoor 230kV substation connected with a hydro electric plant. The ground grids longest dimension is a little over 100 meters. A penstock approximately 600 meters long exists which...
I'm involved in a transformer replacement project where we are replacing two 1000/1500kVA PCB oil filled transformers with dry type transformers in a large mall.
The customers service voltage is 25kV. The 25kV is stepped down to 12.5kV through a 3MVA autotransformer. Downstream of the 3MVA...
I am working on ground grid installations connected to a power utilities 12.47kV 250MVA multi-grounded-neutral distribution system.
The utilities practice is to use single conductor 15kV concentric neutral conductors for distribution.
The phase fault current out of the substation is limited...
I have seen two different types of trailing cables used with ground check.
One style of cable has the ground check wire inside the cable.
The second style of cable which I was told is common is europe has the ground check wire under the outter protective jacket.
The second style seems to...
