Login | Register
The Engineer's Place for News and Discussion®

Previous in Forum: Auto Tripping at Grid Sub-Station   Next in Forum: How Do I Use Battery Power to Electrically Cool an Ice Pack Gel?
Close

Comments Format:






Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







15 comments
Power-User

Join Date: Jul 2011
Posts: 133

Current Injector

05/12/2012 2:53 PM

we have a current injector upto 400A continous current output tap.four taps of 10A,50A,200A and 400A are available which are the currents we can get from current injector continously when selector dial is set at these taps.however a duty cycle is given in the manual of injector as shown below:

now looking at the table ,it is clear that current obtained from injector for 1sec is 2.5KA. which means we can use the 400A tap for short circuit breaking capacity tests of fuses and MCBs etc. but the question is how can i get this 2.5KA at 400A tap for 1 second because once tap selector is set at 400A and the potentiometer for current variation is varied ,the output current of injector will change in normal way from 0A to 400A.

help need in this regard please.

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
Hobbies - Automotive Performance - New Member Popular Science - Weaponology - New Member

Join Date: Oct 2008
Location: 34° 34' 21.60" N, 92° 55' 42.28" W
Posts: 20923
Good Answers: 784
#1

Re: Current Injector

05/12/2012 4:20 PM

RTFM!!!!!!!!!!!!!!!! RTFM!!!!!!!!!!!!!!!!RTFM!!!!!!!!!!!!!!!!

If you don't understand TFM, hire an engineer who can.

Call the supplier and ask for help!!!!Or, CTFS!

__________________
Luck comes and goes. Skill is forever. Intelligence either is, or it ain't. lyn
Register to Reply
Power-User

Join Date: Jul 2011
Posts: 133
#2
In reply to #1

Re: Current Injector

05/12/2012 5:07 PM

CR4 ADMIN: Deleted Post

Abuse/Attack: This post was deleted because it was an attack on another user. Please review the CR4 Site FAQ and the CR4 Rules of Conduct.

Register to Reply Off Topic (Score 5)
Guru
Hobbies - Automotive Performance - New Member Popular Science - Weaponology - New Member

Join Date: Oct 2008
Location: 34° 34' 21.60" N, 92° 55' 42.28" W
Posts: 20923
Good Answers: 784
#4
In reply to #2

Re: Current Injector

05/12/2012 5:42 PM

You, obviously, don't know anything about the equipment you are supposed to be maintaining. Your previous posts here bear that out.

The lack of knowledge you exhibit represents a threat to human safety.

I know nothing about your facility, or the equipment in it. I think you don't either!

At least I admit it.

I'll do my best to ignore you in the future.

__________________
Luck comes and goes. Skill is forever. Intelligence either is, or it ain't. lyn
Register to Reply
Guru
Hobbies - Musician - Engineering Fields - Chemical Engineering - New Member Engineering Fields - Control Engineering - New Member Engineering Fields - Instrumentation Engineering - New Member

Join Date: Jan 2007
Location: Kennewick, WA, USA, Thulcandra - The Silent Planet (C.S. Lewis)
Posts: 2808
Good Answers: 102
#5
In reply to #2

Re: Current Injector

05/12/2012 6:29 PM

you forced me to use such language.

No. No one forced you to do anything. You chose to respond the way you did which was far from "equal and opposite". Not cool at all, coolyaar.

I think you are angry because Lyn brought out the fact that you truly don't know what you are doing.

Ignorance + Dangerous Equipment = Someone getting killed!

Get your composure and some humility. Then we may be able to help you.

__________________
"I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world." -- Albert Einstein
Register to Reply
Guru
Engineering Fields - Electrical Engineering - New Member United Kingdom - Member - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2010
Location: Under the Major Oak
Posts: 3054
Good Answers: 115
#3

Re: Current Injector

05/12/2012 5:10 PM

coolyaar, why would you want to test the breaking capacity of fuses and MCB's?

Like you it's pointless!

__________________
Pessimists are rarely disappointed.
Register to Reply
Power-User

Join Date: Jul 2011
Posts: 133
#7
In reply to #3

Re: Current Injector

05/12/2012 11:51 PM

CR4 ADMIN: Deleted Post

Abuse/Attack: This post was deleted because it was an attack on another user. Please review the CR4 Site FAQ and the CR4 Rules of Conduct.

Register to Reply Off Topic (Score 6)
Guru
Engineering Fields - Electrical Engineering - New Member United Kingdom - Member - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2010
Location: Under the Major Oak
Posts: 3054
Good Answers: 115
#11
In reply to #7

Re: Current Injector

05/13/2012 10:46 AM

Perhaps if you approached the seniors at your facility with reasonable questions they may take time out to help.

If like here you go asking a series of inane unrelated questions it no surprise you get short shrift.

I've asked before, what is your role in this facility? To me you don't seem to have one.

You constantly lurch from one topic to another. There is no cognicant thread to your questions.

__________________
Pessimists are rarely disappointed.
Register to Reply
Guru
India - Member - New Member

Join Date: Sep 2009
Location: Bangalore, India
Posts: 2599
Good Answers: 150
#6

Re: Current Injector

05/12/2012 9:52 PM

You can get 2.5kA for 1s @ 3.45V! What 'breaking' tests do you think you can do? And what is the use of breaking a current after passing it for 1 sec? Think everything out before asking.....

And you may have just burned out your bridges by that disproportionate rant.

__________________
Nothing worthwhile can ever be taught, it can only be learnt.
Register to Reply Score 1 for Good Answer
Guru
India - Member - New Member

Join Date: Sep 2009
Location: Bangalore, India
Posts: 2599
Good Answers: 150
#9
In reply to #6

Re: Current Injector

05/13/2012 5:52 AM

Am i misunderstanding some of the posts or are the posters seriously addressing your point of testing MCBs and fuses with this thing? Let me repeat...you have 2.5kA at 3.45V. You can't do any breaking tests with this current injector. You need a recovery voltage of 415V. You can, at best, do some limited Icw testing. It is meant for passing a large current at low voltage for temperature rise tests. If you want to do a short-circuit tests, you need to go take a look at the equipment at CPRI or ERDA. There is no free lunch.

__________________
Nothing worthwhile can ever be taught, it can only be learnt.
Register to Reply
Power-User

Join Date: Jun 2009
Posts: 210
Good Answers: 1
#8

Re: Current Injector

05/13/2012 4:26 AM

how can i get this 2.5KA at 400A tap for 1 second because once tap selector is set at 400A and the potentiometer for current variation is varied ,the output current of injector will change in normal way from 0A to 400A.

Power the injector just after the tap and the potentiometer have been set for the necessary current (and the fuse or the MCB is already connected to the output).

Register to Reply Score 1 for Good Answer
Power-User

Join Date: Jun 2009
Posts: 210
Good Answers: 1
#10

Re: Current Injector

05/13/2012 6:35 AM

This tester being of course used for testing of the settings of solely the thermal safety devices. With toltage dropping down to almost 0 V with the highest currents.

Register to Reply
Guru

Join Date: Dec 2010
Posts: 683
Good Answers: 50
#12

Re: Current Injector

05/13/2012 5:35 PM

Coolyaar,

What the maximum currents and times mean is that the injection tester components will heat up to their maximum [from cold] at the tabulated time and current. Any more current or time and the tester may overheat. Consequently it may lose accuracy permanently, have reduced life or fail.

This is a behaviour of any equipment with a "short time rating", not just an injection tester.

For times of one minute or longer, one can just use a "cooking timer" or clock to help keep to the time limit. For 1 second, to avoid risk of tester damage, it would be best to fit an automatic disconnect timer.

Not knowing how your test source or "test rig" works, I am unable to recommend anything.

Guessing that the tester is powered from a standard mains socket and its output current causes a proportional input current ; then a mains input overload breaker or fuse with current time curve "inside" that of the estimated tester INPUT "withstand" current-time might be a simple solution. If the tester has a transformer, then its "inrush" current might trip such a sensitive breaker - it might be necessary to bypass the input breaker temporarily at switch-on by a "fool-proof" switch which isolates the test current output.

If you are as abusive to people you ask "face to face" as you have been to Lyn, I can see why you do not get good answers. The message that helping you is an unpleasant experience is likely to travel quickly around those who might help you!

I suggest you apologise to those with whom you have got angry over answers, Lyn would be a good place to begin (at least you do not have to get into his office and endure the growl and scowl on the way).

No one who has been responsible for his own safety in what he does or responsible by example or word or document for people's safety will stay tolerant when they feel their advise is being ignored where injury or death is possible.

67model

Register to Reply Score 1 for Good Answer
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing. Kettle's on.
Posts: 19574
Good Answers: 469
#13

Re: Current Injector

05/14/2012 9:18 AM

Fuses don't get tested at site. By definition, when a fuse operates at or above its rated current, it needs replacement after the test. So fuses are type-tested by a testing authority and the performance curve of the fuse gets published so that an Electrical Engineer can make an informed selection according to the duty.

The same applies to overload breakers, except these don't need replacement.

Current injection test of a fuse? How abstruse.

__________________
There was a time, not long ago, when people were smarter than their phones... (tips hat to CR4 user Harley.)
Register to Reply
Guru
Engineering Fields - Electrical Engineering - New Member United Kingdom - Member - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2010
Location: Under the Major Oak
Posts: 3054
Good Answers: 115
#14
In reply to #13

Re: Current Injector

05/15/2012 8:43 AM

They could be BS3036 fuses.

I seem to recall him asking about 11KV rewireable fuses some time back. I dread to think what's in his mind!

__________________
Pessimists are rarely disappointed.
Register to Reply
Participant

Join Date: May 2012
Posts: 1
#15

Re: Current Injector

05/29/2012 6:00 AM

I mostly work with Primary Current Injector. The Current Injector is one of the essential parts of the Vehicles. Almost all electricity supply equipment is fed from a current transformer on the supply cable or bus-bar. The Primary current injector testing checks all the components of the protective system. These Current injectors need signal injection for a different type of test. These are up to the standard of the device being tested. There are many features of these current injectors which supports the vehicle to run smoother.

[url=http://www.amperis.com/en/products/relay-testing/rdf200/]secondary current injector[/url]
[url=http://www.amperis.com/en/products/relay-testing/rdf200/]relay tester[/url]

Register to Reply
Register to Reply 15 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

67model (1); anthonynoahan (1); coolyaar (2); kvsridhar (2); lyn (2); Mikerho (1); PWSlack (1); TonyS (3); Yuri B. (2)

Previous in Forum: Auto Tripping at Grid Sub-Station   Next in Forum: How Do I Use Battery Power to Electrically Cool an Ice Pack Gel?