Hi DBL-E,
Thanks for response.
Design goal is step and touch safety and low impedance connection to earth as incoming lines have no return path.
Not sure what you mean by group potential rise, if this is the interconnection of the main sub grid with all of the other grids on surface, i.e...
Does anyone know of any papers/articles that discuss remote ground grids / ground fault current and their affect on wildlife? Does anyone have experience with this?
Currently working on a substations design where the sub is basically on bedrock with high impedance to earth and can't achieve...
@RRaghunath - I am not sure at all.
I had a conversation with one of the transformer suppliers regarding my situation and this is what I picked out of the conversation. It is possible the manufacturer didn't speak about any higher voltage as I am only dealing with 44kV on the HV side and I may...
Thanks for all input.
I couple items I was able to sort out in talking with one of the transformer suppliers that may add to the conversation.
If the tap changer goes on the HV (primary in my case) the tap changer typically has to be a high speed resistance based type which using a mechanical...
Just looking for some information on why tap changers would be spec'd on the primary or secondary of the transformer.
Scenario - 44kV/13.8kV - delta/wye - 15/20MVA - online tap changers
Primary side taps
- This is the less expensive option
- This is the more common option
Secondary side taps...
Ideally would like to start at the panel or power source and follow cable to find out what load it is connected to, could be receptacles, could be lighting, could be process equipment. Because of the plant size to be able to do this you almost have to be able to trace the cable route as cable...
Has anyone used equipment that has reliably traced steel and aluminum armored Teck power cables? Having issues on site when trying to trace a cable from the panel board out to the end load. Ideally would like to be able to do this live so we don't have to wait for down day to trace them out...
Thanks for all of the input.
If the client does want further study of this option I will post what the findings are in terms of potential power savings. At this point we have many opportunities and they will likely only select a few to study in depth.
Thanks again.
I have gotten involved in an energy study and the question about adding power factor correction to try and reduce line current came up. The client's design criteria currently states 0.9PF and we are looking at increasing this to 0.93PF.
As this is a energy study the question of how efficient...
Thanks Keith,
I guessed at 92 as it is an older motor. If 92 is a poor assumption for this older machine I can bump it up a little. If 97 works for older machines I will use that. I won't be able to get name plate data in time so have to make an assumption.
Cheers,
Jeff
Can someone confirm if this works to calculate horsepower for a motor?
I had some metering data provided on a 700hp motor. One of the measurements was kW and I was wondering if I can take this divide by 0.746 to get horsepower.
This would basically give the "electrical horsepower" then if I...
To add a little about our system.
1. System is resistance grounded with monitors that alarm first then trip.
2. Lightning arrestors on the main incoming (115kv)and on secondary (13.8kv)
3. Remote ground grid to give our low resistance connection to ground
4. System is less then 2 years old...
On site we have construction going on and a question was posed to me today and would like other peoples options on it.
They are going to be digging around the existing 4/0 bare copper ground cable that runs around the main building and I was asked if there is a fault to ground if there any...
I have been asked to do a comparison on different blasting technologies and I have no experience with blasting. The three technologies I have been asked to look at are conventional, Orica's I-kon system, and a PED system(Mine Site Tech). Need to find the pros and cons on each of these systems...
