Thanks every one.
A bit more info.
The client wants to keep the refurb costs to a minimum; hence the 415V cables from the txfr, in another building, are to remain, but jointed onto new SWA cables to allow us to bend these onto new 415V switchgear.
I'm not sure of the existing sizes and will...
I am involved in a refurbishment project that has old (imperial) PILC cables. These date from the early 60's.
Does anyone know where to find a table for current carrying capacities?
NB This is in the UK if that makes an difference.
I have the reactances from the manufacturer and want to ensure the final circuits are clearing correctly i.e 5s max. Should I use the sustained If with impedance of 0.04 or a combination or something else?
Xd 2.96
X'd 0.18
X''d 0.13
All at 1550kVA base 400/230V.
I am struggling with a fault calculation for a generator installation.
I have a 1500kVA 400V 3ph generator with instantaneous If 16655A, short term If 12028A for 0.135s and sustained If 5,400A. But what do I imput for the external impedance; is it simply 230/5400=0.04?
Exxit
If I close the Find and Replace window and zoom with the mouse wheel the zoomed in/out as far as possible is displayed, but nothing on the screen. If I double click the mouse wheel it zooms to extents, which isn't a great deal of help on a building 400m long.
The AutoCAD solution...
Thanks Exxit
Still doesn't work. When I go Zoom To I just get blank screen. If I try to zoom using the mouse wheel the screen is still blank when zoomed in as far as possible or zoomed out as far as possible.
Does the Zoom To command work in Autocad LT2000? Using the Edit>Find command I can locate the text string I'm looking for, but when I hit the Zoom To button I get a blank screen.
All the layers are on/unfrozen so I don't understand what's going on.
Any offers?
I am involved in a UK project that has a 11kV/433V sub-station, but have come across conflicting information regarding REF protection. Are there any hard and fast rules when REF protection should be used on the LV side of a transformer and when it shouldn't?
If it is/isn't used what are the...
I have been looking at a drawing showing protection of HV, transformers, generators and LV. The drawing has the protection relays shown as numbers e.g. 51N, 96N, 32 and so on. Can anyone tell me where it is possible to find a definitive list of these as I know some but not all.
By the way...