Maybe I overeact there or maybe I was anticipated overeaction from my trainees when I would have to debunk the "second degree burn" case. Even if NFPE 70E or the canadian equivalent CSA Z462 are not legaly binding, we have a criminal law that my clients have to comply too and showing that they...
I'm concerned since as you told, they making changes so that the criteria is not based anymore on second degree burn threshold but on an incident energy level which we believed was the threshold.
Being a trainer on arc-flash matters, I always explained what represent the 1.2 cal/cm². So to...
Searching for reference about insulation coordination, I consult thread238-232606 from 2008 and though I should comment about what I find.
Background
First, I was questioning myself if a ACWU90 600V cable was suitable for a 600V application (Québec, Canada) considering that, by common practice...
Hi
I have a number of feedthrough connectors TCF125-128AL for mono DLO 535 cable. The diameter of one end is too small. It's cause of varying OD diameter of the cable manufacturers. Southwire would have fit but not Carol.
My men proposed to grind the opening end for 3/32 inch width.
I was...
Hello
I'm looking for reference and opinion about Fault current limiter.
Question Is there any papers or reference that allow to calculate, to compute, to quantify peak short-circuit reduced by a current limiter on all the load side assemblies?
Context :
Arc-Flash, short-circuit and...
I give a star to david too.
Basics are the key. Understand, Simmi, that a transfomer is an application of electromagnetism theory. To understand the why is there an inrush current, you must understand the magnetic relation between the windings and the magnetic core of a transformer.
I agree...
Thanks for the acronym.
The project is for a mining complex. They act as community, utility and previous module design served as pre-approved philosphy that we adapted to this projet. Past history shows no use of filler to improved conductivity for their current installation.
I would ask about...
A ground rod provider suggest a fill to enhanced conductivity between rods and soil.
Though, the provider didn't know about the arctic condition of the project.
But it might be more than just structural design consideration but also an environnemental consideration since environmentale...
I'm actually designing a grounding systems for arctic climate.
This thread is a follow up of an older thread thread238-196015 as to be a sample application.
1.0 Definition
Artic : Regions where the soil is compose of permafrost. It includes Alaska, Northern Canada, Northen Scandinavia...
My usual rule of thumb is this :
Xmer KVA = 4(kVA/HP) * Pmotor(HP)
For your 100A motor (assuming it's a 575V), that rule would size a 400kVA.
I seldomly used that rule. I prefer do the following calculation :
1 - Evaluated the Locked Rotor Ampere - Usually a percentage of the FLA typicaly...
3.Executive Summary
I put an executive summary section after defining the scope of project. It's a summary of the results and recommandations written without the too much specific technical vocabulary. It's intended to the client. I prefer it at the report's first pages than at the end. So...
I'm a consultant firm member. My typical week, as describe in the employees manual, is 37.5 hours a weeks flexi with reccommended working hours from 8:00 to 16:30 with an hour lunch. I also have an overtime pay rate for excess hour over 40 a weeks (it's by province laws). I have the option to...
Lastest feedback on the project
They decide to install a SEPAM-1000+. They won't dismantle the currently installed LGPG111 since there is room to install the new equipment. So they will just disconnect it and reconnect the CTs to the SEPAM.
Thank you Slava for the continuous assistance you...
Hello Slava
Thank you very much for your help.
I'm confident now that we will be able to make our recommandation about the option of using the existing LGPG111 in regards to the option.
The second option is to replace the LGPG111 by a relay with only 25-27-50-51-50GS-51GS (KCGU-140). Such...
Wow, thanks. It left me with one more interrogation.
About note 3 from your 23:35 post, I thought I could disabled those function. PW1 generator have each their own generator protection set provide by the manufacter (That point might not have been clear in my previous post). Since each...
Answers to new questions :
1. No, there is no connection to utilities. The context is a remote mining site, where tundra is the kind of vegetation. There are 13 generator including the fives shown in the scheme. Seven of them are supposely dedicated for back-up supply.
2. Yes. When the PW1...
Thank you
I attached a scheme of the connection between the two powerhouse. The relay in question will protect a transformer on the 4160V side. The winding are Delta on 600V and WYE (without ground) on 4160V. The 4160V bus bar is at the main power house and is tie with an other bus containing a...
I would like to find documentation about how the current direction could affect the proper fonctionning of a protective relay.
We are connecting a 600V power house (PW1) to a 4160V power house (PW2) throught a step-up transformer.
The grid configuration can allow to feed PW2 with PW1 and vice...
The distance between the distribution sustations and the mining site is 75 km.
The fault level at the end of the line would be 250MVA @ 120kV and 115MVA @ 69kV. They allowed a 3% maximum voltages sags from motor starting. So, 500MW is about the largest motor power allowed @ 69kV.
But...
Hi
Question : Does a volatage regulator for 69kV line can could be used for a 120kV and vice versa? Does a auto-regulator on a line supplying 10MW would be affected and/or need to be change if we rise to 20MW.
Link about high-voltage regulators would be appreciated.
Project : Mining site...