Previous in Forum: why to ground a computer   Next in Forum: What Is Syn-Check ?
Close
Close
Close
16 comments
Rate Comments: Nested
Member

Join Date: Nov 2007
Posts: 9

Blinking Incandescent Bulb

11/20/2007 4:08 AM

We have 5 x rated 1MW /415V /50Hz Generator set and are fully automated control system. 3 Genset are always online to supply the power demand of 2.4 MW gold proccessing plant and Underground Mining Equipment

I need your help. Why all our lighting circuit are blinking? especially incandescent bulb. Is this is cause with Frequency, voltages or etc?

I have trouble fixing or correcting the problem on our power generating unit for the past 3 week now. Please send me the tips.

Calmade

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

"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, vote them!
Guru

Join Date: Nov 2006
Posts: 729
Good Answers: 2
#1

Re: Blinking Incandescent Bulb

11/20/2007 6:07 AM

I presume all load including the Bulbs are on 3x1 Mw gensets.The generators must be running in parallel to supply 2.4MW.The load is varying ie a sudden demand and then ease off like in a press or Furnace.The generators are not able to support the sudden demand for power and hence there is a voltage and frequency drop which is seen clearly in the Incandescent lamps.Check the voltage and frequency when the lights are dimming and again when brightening.Try running 4x1 Mw .U may not have this problem.Another problem could be a low PF which makes the generators underrated.So in all probability running 4 in parallel may solve this problem.

__________________
To avoid crticism do nothing,say nothing,be nothing
Register to Reply
Member

Join Date: Nov 2007
Posts: 9
#7
In reply to #1

Re: Blinking Incandescent Bulb

11/23/2007 3:45 AM

Since we start the plant the load has not increase or no additional load has hook-up. This problem has just happen recently, after the do 15,000 hours service on the cummins engine.

Register to Reply
Guru

Join Date: Aug 2007
Location: Indiana, USA
Posts: 579
Good Answers: 61
#2

Re: Blinking Incandescent Bulb

11/20/2007 2:16 PM

1. Has the blinking always occurred in this configuration, or is this a new problem?

2. Are the lighting circuits connected at generator voltage, or is there a transformer involved?

3. Are the lighting circuits connected line to line, or line to neutral? (If line to neutral, I suspect the lighting panel may have a damaged or loose neutral connection.)

__________________
Experience: The knowledge you gain just AFTER you needed it.
Register to Reply
Anonymous Poster
#3

Re: Blinking Incandescent Bulb

11/20/2007 11:54 PM

Blinking could be attributed due to following :

1]Loose connection including neutrol.

2]Suddon demand in load drops the frequency.Dimming will also be noticed during this period. Please observe & record the dip in voltage and frequency.

3]Genset governer could be sluggish.Please chech the governer performance and the droop.

4]Check the fuel quality , fuel filter cleanliness and air filter condition.

Register to Reply
Active Contributor
Engineering Fields - Optical Engineering - New Member

Join Date: Mar 2007
Posts: 10
#4

Re: Blinking Incandescent Bulb

11/21/2007 12:55 AM

How fast does the blinking of lamp occurs?

Most probably frequency of voltage generated (50Hz) from one or more alternator is not matching.

Have you checked the frequency of each alternator output before synchronising to bus bar?

Register to Reply Score 1 for Good Answer
Guru
Hobbies - HAM Radio - New Member United Kingdom - Big Ben - New Member Fans of Old Computers - Altair 8800 - New Member Canada - Member - New Member

Join Date: Jun 2006
Location: Toronto
Posts: 3968
Good Answers: 120
#5
In reply to #4

Re: Blinking Incandescent Bulb

11/21/2007 7:17 AM

the generators are shifting out of phase = shorting and then coming back in a cyclic manner.

This can harm the gen sets .

Since this is a new problem, something must have failed/changed in the control circuitry that is supposed to keep all three online and in phase.

Read the manuals.

__________________
Per Ardua Ad Astra
Register to Reply Score 1 for Good Answer
Anonymous Poster
#6
In reply to #5

Re: Blinking Incandescent Bulb

11/22/2007 3:27 PM

Check the output voltage of the AVR for proper stability setting (gain).

Does this happen evry second or so or randomly? If random, load response to AVR output needs to be investigated.

Register to Reply
Member

Join Date: Nov 2007
Posts: 9
#10
In reply to #6

Re: Blinking Incandescent Bulb

11/23/2007 5:37 AM

It happen every half second contineously, especially when the load or our 1.5MW sag mill motor is running.

Register to Reply
Anonymous Poster
#12
In reply to #10

Re: Blinking Incandescent Bulb

11/23/2007 11:23 AM

Check the DC output from the AVR to the generator(exciter) for fluctuation and REDUCE the gain setting slichtly to stop the ossilation.

Register to Reply
Member

Join Date: Nov 2007
Posts: 9
#8
In reply to #4

Re: Blinking Incandescent Bulb

11/23/2007 3:56 AM

All plant lighting are blinking continoiusly in every half second. I checked the frequency is fluctuating between 50.05Hz to 49.92Hz.

Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#9

Re: Blinking Incandescent Bulb

11/23/2007 5:01 AM

This could indicate a serious problem in the phasing of generators. Try supplying the lighting from a single source (generator) and see if the problem is fixed....

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Member

Join Date: Nov 2007
Posts: 9
#11
In reply to #9

Re: Blinking Incandescent Bulb

11/23/2007 5:47 AM

I test all genset by loading the plant lighting circuit only and it doe's not blinking it's okay.

Register to Reply
Power-User

Join Date: Oct 2007
Location: Pune, India
Posts: 132
Good Answers: 2
#13

Re: Blinking Incandescent Bulb

11/23/2007 11:45 PM

could you please check UK regulation P28 in this regard, it will give you some fare amount of idea.

thanks

__________________
manirul
Register to Reply
Anonymous Poster
#14

Re: Blinking Incandescent Bulb

11/25/2007 5:21 AM

Do you any large capacity Thyristor controller to control some heavy load like heaters? If yes fine tune your PID. I have faced similar problem few years back; could rectify by fine tuning.good luck.

Register to Reply
Guru

Join Date: Feb 2006
Posts: 1758
Good Answers: 6
#15

Re: Blinking Incandescent Bulb

12/10/2007 1:49 PM

Is the Sync; Voltage comparing; Power-Sharing; Transfer of load are Automatic or Manual?

Before Shifting of Load:
Normally all the Power-Sources are connected to Out-Put Assembly one by one & put on load.

Lighting load is also pure-resistive.
Any Inductive Load? Specially Varying-Speed [even due to varying or Withing On-Off type.

Seems to be problem in "Synchronising" of generators or mis-matching voltage.
But in Automatic Systems problem-creator is Isolated after some time.

Low-Power-factor seems to be not there due to Incandescent-Bulb load.

Control Gear [Control Assembly may be problem.
Try putting a part of lighting load on a single generator, one by one.
If no problem it is Sync problem. Look in the relevant control.

Unless you are on-site only probabilities can be listed.

Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#16

Re: Blinking Incandescent Bulb

12/10/2007 7:07 PM

As I have mentioned before, make sure that they are all supplied from ONE generator for a time as what I think is happening is that the line is from one generator and due to inaccurate wiring, the neutral is from another. The two Gennies are running, BUT NOT PARALLELED to each other!! You might be seeing the difference in frequency....

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Register to Reply 16 comments

"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, vote them!
Copy to Clipboard

Users who posted comments:

Andy Germany (2); Anonymous Poster (4); aurizon (1); calmade (4); Haajee (1); manirul (1); nesubra (1); pwr2thepeople (1); Raghavendra (1)

Previous in Forum: why to ground a computer   Next in Forum: What Is Syn-Check ?
You might be interested in: Incandescent Lamps, Lighting Fixtures, Lamps

Advertisement