I've been asked for some grid quality requirements in a project. One of those parameters is current asymmetry. I'm trying to find any regulation or standard about it but I can't find. Does anyone know?
Thanks in advance.
Hi all,
An industrial facility owner who suffers from frecuent untimely RCDs tripping in his facility was adviced to convert the existing TT earthing system into TNS. We've been asked to quote the engineering project for that. I've never seen this done before but I guess it is not quite...
I'm working on a project of an existing facility. There is a main switchboard with a molded case circuit breaker in the incoming whose breaking capacity is insufficient for the calculated short-circuit current. That incoming circuit will be properly protected in its beginning, by a new circuit...
Is there any way of getting the sum of the lengths of multiple polylines selected in Draftsight? I used to do it in AutoCAD with a LISP macro.
Thanks in advance.
Hi,
I was wondering if there is some standard that considers the situation of an HVAC system for a substation building during a main power supply loss. I'm participating in a project where ventilation was considered to be fed by a backup power supply but no air conditioning is posible while...
I've been searching for any european standard that stablishes the required distance between overhead power line and hazardous (ATEX) area but I couldn`t find anything. In my case I have a 66 kV line over an outdoor propane/butane bottles storagement rack in Spain.
I'd appreciate any help.
IEC 60076-1 and other standards detail a concept of a tolerance in short-circuit impedance value. As I understand this tolerance must be taken into account during the process of manufacturing the transformer, as it is hard to define initialy the parameters to achieve the required impedance and...
According to IEEE standard and others a derating factor must be applied to consider the effect of worse ambient and site conditions (altitude, ambient temperature) over an oil immersed power transfomer. As I understand, to assure the transformer won't suffer any damage, the transformer...
Hello,
I'm designing an electrical facility to feed some motors (>75 kW) through VSD. We consider some ANSI proteccion functions in the switchgear (50, 51, 86) as if it was a feeder possition and we consider the specific motor protection functions in the engineered VSD. Some of the vendors in...
In some specific files I got the error "Copy to clipboard failed" when I try to copy any object, so I cant copy no object to another file. There should be some problema with those files. I cleaned them and audit them but it did't solve the problem.
Any idea?
Thanks.
In presentation mode I cant' edit the snap points of a poligonal window. When I try to click on a snap point the windows just get deselected so I can't find a way to edit the dimensions of the window.
Any idea? Thanks
Sometimes when I open a file an when I close a file with draftsight I get the next error: "COM Surrogate stopped working". Draftsight works perfectly but it's a little anoying.
Any idea?
When you copy (Ctrl+C) an image in Windows and paste it (Ctrl+V) in AutoCAD you get an image inserted in your file, not an external reference, but an OLE object. When I open this file in DraftShight I can see the image and the properties menu says it is an "OLE (1)" type object but I don't know...
I have a dwg file where I hide some layers in an asociated external reference and save the file. Everything normal up here but when I re-open the file I find that all hidden layers are visible again. I suspect the problem could be the file because I don't find the same error in other files.
Thanks.
When I open some files in Drafsight I randomly can't see the attached images. I just can see the edge of the image. I can move, copy, scale, rotate it. Everything but see it in model space. When I go to paper space I can see the image perfectly.
Any ideas?
Thank you.
