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Blinking Lights
2

Blinking Lights

Blinking Lights

(OP)
At my house I have a 5 ton, 2 stage scroll compressor condensing unit, and my house lights blink on the unit starting.
Specs are 118 LRA, 230V, 23 FLA.

Lamps are incandescent 130 V.
Service size is 200A, 120/240V, single phase
Measurements at the unit disconnect switch are:
Normal Voltage 246 V
Starting Voltage: 231 V
Starting Amps: 121 A
Running Amps: 10 A (Low Stage)
Starting time: 1 second.
Start is on Low stage.

This is on a 1 year old house and has done this since installed.
There is no issue when the compressor goes from low stage to high stage.

Neutrals have all been checked, Meter, Panelboard, and are all tight.

Power compnay service is: 50KVA transformer, 7 Houses on overhead lateral, my service drop from lateral tap to service is 80ft., lateral distance tap to transformer is 120ft. POCO conductors are aluminum don't know size. POCO not interested in my blinking lights with such small voltage drop.

Attached is the Power company recording of Voltage and Current at my service.

I was thinking placing a capacitor at my service may mitigate the dimming lights. Any thoughts.


RE: Blinking Lights

That recording is just moot.

The samples are taken with minutes between them and cannot show anything about flicker.

Make the utility do a correct recording. Then you (and they) will see what is going on.

It is obious that the starting current makes the lights flicker. And there are usually limits as to how much flicker one shall tolerate. At least, there is in the EU.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Blinking Lights

When your compressor is starting, you are creating an additional 6% voltage drop possibly bringing your lamps supply voltage at 89% of their nominal voltage (although I am not sure if you measure the voltage at your supply or the compressor terminals). Incandescent lamps rated 130V are usually used as "long lasting" on 120 V system. Operating in the upper voltage range is known to shorten the live of 120V rated bulbs so installing 130 V bulbs is a proven solution for system operating in 120+V range. The inconvenience to such choice is that when operating in the lower voltage band, you will more easily perceive the change in lighting since the lamps are at 89% their nominal.

The utility is not likely to help unless your neighbors start complaining. Your compressor is likely meeting standards although with a 6% voltage drop you are technically limited to a few starts a day max. Have you thought replacing your bulbs with LED? The are less voltage sensitive.

RE: Blinking Lights

I've found a few cases like yours in which the meter socket is the culprit - a not-tight-enough contact. Could also be a loose connection at the panel main.

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies

RE: Blinking Lights

(OP)
The voltage measurements are at the compressor, so my service voltage drop is not as severe. I have measured 4V drop at the service under compressor start.

LED's are not an option since they will not work with my dimmer switches.

I changed a room of lights to 120V, and could not notice any difference in the dimming on compressor start from the other rooms that are 130V.

RE: Blinking Lights

(OP)
All connections, hots and neutrals, have been checked for tightness, meter pan and meter pan jaws, service panel, and taps at the pole (by power company).

RE: Blinking Lights

Loose connections commonly cause this issue, but since you've checked that out then you might try using capacitance to reduce the starting VAR surge. However you don't want the capacitance at the service entrance, rather you want it at the compressor, and only while it starts. Have you tried talking to your local HVAC company which represents the installed equipment manufacturer? They will likely recommend a "hard start kit", which basically adds more start capacitance to the compressor. There are several companies making these kits so if you want more details just use your favorite search engine.

RE: Blinking Lights

(OP)
I don't think the hard start capacitance is large enough to make a difference.

RE: Blinking Lights

Keep in mind the start capacitance isn't being used to directly provide the ~100 extra starting amps, rather it only affects the start winding current phase angle with respect to the run winding current phase angle. Thus although the start capacitance is small, it has a large effect on how quickly the motor spins up to normal speed, which in turn has a large effect on how long the motor draws the extra starting amps.


RE: Blinking Lights

(OP)
I obtained 2 - 100 ufd run capacitors and connected them in parallel to my service.

The blinking lights are not noticeable with the capacitors in the circuit when the compressor starts.
I did 10 test and unless you are looking directly at the lights the blinking is not perceivable.

RE: Blinking Lights

The 121/118 Amp LRA/starting current has a large reactive component. Capacitors will supply part of the reactive current and so reduce the starting current. There have been proposed reduced current motor starting schemes which use enough capacity to supply all of the reactive current when starting. The reactive current drops as the motor accelerates. The capacitors are disconnected in steps as the motor accelerates.
I say proposed because these starting schemes have not been widely implemented. (I have read the paper but I have never seen this scheme used in the field.)
Enough capacity to supply the locked rotor VARs is too much for continuous use and may lead to over voltage and other issues.
You seem to have found a sweet spot with enough capacity to mitigate the lamp dimming.
It would be interesting to know if your voltage rises when the capacitors are turned on, and the current drawn by the capacitors.
You may get better results if the capacitors are connected at the motor end of the motor feeder. Maybe not. There are some offsetting factors which are hard to estimate.
VARs supplied at the motor terminals will result in less voltage drop in the feeder and so more starting current, but a higher voltage will result in more VARs from the capacitors, tending to reduce the current. Then the retio of the cable impedances from the transformer to the service and the service to the motor will be a factor. Given the high reactive component of the starting current the cable reactances are also a factor.
If you are happy with the results, I would not move the capacitors.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Blinking Lights

(OP)
With the capacitors in the circuit the voltage rises 2V. I, like you, am more concerned with the capacitors in the circuit when I don't need the capacitor KVARS and neither do my neighbors, that my voltage will rise to much, which will have bad effect if not short term, at least long term.

RE: Blinking Lights

You can probably all live with a 2 Volt rise. You may want to re-check the rise with everything but the capacitors turned off. That will be the worst case of voltage rise on the grid.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Blinking Lights

It is fine to talk of the FLC but what about the conductor size and distance? I am presuming that your feed from your 50kVA transformer comes to a Distribution Board and from there you feed your lights and compressor. The combined voltage drop on this feed that is causing the voltdrop at the common point of connection. Look at your conductor cross sectional area of your feed cable. For 180A on a short distance it is 50mm Sq. As your load is not normally this high, you would size the cable to your load.You may have only a 16mm sq cable. This reduced size is also dangerous due to fault levels.

Then you state that you wish to use capacitors. Yes they will lift the voltage if you install them at the DB. This will help when starting but not enough. Yes the 2% rise is fine, you should not even see the difference and the shortening of life span won't be that great.

If you put the capictors on the motor terminals you really will have a problem. There will be an inrush due to the motor starting and charging of the caps. In my view the dimming will get more pronouced due to the even greater current draw.

What about star delta starting or a soft starter to limit the current draw.

Then finally it may be the voltdrop on your Utility's side or loose terminals on the transformer, LV and MV.

RE: Blinking Lights

The motor inrush and the cap inrush subtract, not add. Basic AC circuit theory.

RE: Blinking Lights

squeeky

As davidbeach says.

It is true that there is a capacitor charging when switching on, but that charging is over in a few hundred microseconds and does not make light flicker at all.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Blinking Lights

Dear Guys, Practical experience. Capacitors require special contactors. On AC it sees it as a short circuit until it is charged, yes it is quick but when combined with the inrush of the motor current it is additive until the capacitors are charged, then one counter acts the other. I've done this. If you look at point of consumption connection pfc, there is a time delay before the cap comes in. The motor contactor comes in and the 1 second later you energize the cap contactor. In bulk pfc, delays and discharge times are built in. We need to define the blink (not flicker) that was the part of the queation. The blink is the voltage drop on the motor starting and then it returns to normal. Quick dimming and then back to normal. Flicker is different.

RE: Blinking Lights

Sorry squeeky, you are in the wrong ballpark.

The switching of the capacitor is not a problem in a system where impedance is as high as it is here. It is not about switching huge PFC capacitors at the PCC, where Isc is huge. It is about connecting a motor/capacitor to a grid that is quite weak (with a substantial X in the transformer) and therefore limits the charging current. I see no reason to worry about the contactor.

I dare say that davidbeach has a lot of practical (and an immense theoretical) knowledge. And, if may say so, so have I.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Blinking Lights

Thanks for the vote of confidence, Gunnar.

RE: Blinking Lights

Back in the days before PF controllers became common, it was common practice to connect caps to the motor terminals to correct the power factor. There are probably millions of applications still running out there. Caps on the motor terminals reduce the starting current.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Blinking Lights

(OP)
I obtained 2 - 100 ufd run capacitors and connected them in parallel to my service.

The blinking lights are not noticeable with the capacitors in the circuit when the compressor starts.
I did 10 test and unless you are looking directly at the lights the blinking is not perceivable.


My test was flawed, and the lights do still blink with the capacitor in the circuit, for what appears to be a lesser duration.

Back to the drawing board.

RE: Blinking Lights

Get some proper test equipment and present some measurements of what is happening.

RE: Blinking Lights

If the caps remain connected to the motor side of interupting device when the motor is switched off (normally or abnormally), you need to be careful that you have not overcorrected. If overcorrected, the LC resonant frequency of motor/caps is below line frequency, and the motor residual voltage will excite that resonance during coastdown, potentially causing large overvoltage.

=====================================
(2B)+(2B)' ?

RE: Blinking Lights

(OP)
ScottyUK (Electrical)
27 Jul 14 12:08
Get some proper test equipment and present some measurements of what is happening.

All I have is a digital voltmeter and ampmeter. They have min and max functions, but only tell what is expected from a steady state view. I don't have access to transient type recorders.

RE: Blinking Lights

(OP)
I installed a hard start kit (100 microF Cap and voltage relay) on the AC compressor and my clampon read 23A on compressor start, and lights still blink.

RE: Blinking Lights

That's unfortunate, but since the hard start didn't help you then try to locate and attempt to reduce the voltage drop occurring during the compressor start. Since you've checked for loose connections and found nothing, perhaps instead the wiring is undersized, nicked, or corroded? The voltage drop might be internal to the breaker panel, or even in the main breaker itself.

Since you don't have an oscilloscope or similar equipment to help track down the problem, perhaps use a couple of the blinking lamps? If you can find an upstream wiring connection that doesn't dim the lamps, then you can pinpoint if the voltage drop is mostly coming from one connection or device. However if you get all the way to the service entrance and the lamps still blink, then you'll have to talk with your utility, and after much discussion they might replace your service run or transformer. However some fights aren't worth the effort, you'll have to decide if it's worth the time and energy. As others have noted you may also want to consider switching from incandescent lamps, some alternatives aren't as sensitive to voltage variations and offer a good payback via energy savings and longer lamp life.

Best of luck!
Sean







RE: Blinking Lights

Dear David and Skoggs,

I will accept what you say and wait for the next opportunity. We will soon be looking at a project where the manager does not want a PF controller but a correctly sized capacitor connected to the motor to correct to 0.95pf. Our standard practice would be to use the N/O auxillary contact on the contactor to bring in the capacitor contactor. If the job goes ahead and we have time during the commissioning, I will bridge the N/O and see what happens. I am very fortunate to have access to a Power Quality analyser and if I can book it for the commissioning I should get some good scans. All going well I should be in a position to post something and hopefully upload the results where everyone can see them. I will be very interested to see the results and may have to consume humble pie. It will have 5 x 45kW motors, 4 pole, 400v, B3, foot mount, IE2 motors. Project due for installation in November / December this year. Hold thumbs.

RE: Blinking Lights

Dear Gunnar and David, Purhaps the problem lies in the sizing of the capacitor for pfc or stopping blinking. As I now see it the cap has to supply sufficent voltage/ power during the start up duration to prevent the blink. Sizing calculation would be interesting. I found this, see inserted file. Does this mean that we should only correct for the no load? It seems that we would have to correct for the voltage drop and duration as it seems to be an energy problem not voltage as the cap is at the point of utilization.

RE: Blinking Lights

(OP)
I made more readings of compressor starting amps with the Hard Start Kit and captured 111A starting current.

The power factor correction problem can be analyzed using steady state methods (motor nameplate values, steady state rated power values and phasor arithmetic).

The Blinking light problem is a transient analysis problem and it appears the blinking lights cannot be 100% mitigated, see attached paper.

I believe the only practical solution for my blinking lights is for the power company to install a larger transformer that has less internal impedance and can supply more short circuit current.




RE: Blinking Lights

Dear Markstg, Good paper. Only took 15 minutes to download Africa style. This puts a different slant on things. You bring the cap in first at the starter and then close the contactor, thus storing energy ready for the voltage dip. As I see it, it was the exact opposite of what I stated very early where the motor contactor came in and then the cap from the auxiliary of the motor contactor to prevent the inrush. At least I had the anti-recycle timer in. I see the dates are 1967 so the equipment would have still been around in Africa in the early 1980s when I became an appi. We go to tender on the pump station next week. I promise to give feedback in the starting if I go up to Malawi to commission. Thank you.

RE: Blinking Lights

How can a capacitor possibly 'store' anything for an inrush issue? We're talking AC here. Many cycles are involved.

All a capacitor can do in this case is reduce a weee bit of voltage loss to the motor due to reduced power factor during starting.

Or am I missing something?

BTW: The brightness of an incandescent bulb varies by the more than the 3rd power of the voltage. A voltage drop of 6% results in about a 20% drop in light output.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Blinking Lights

No Smoked - you are not missing anything.

I tried to tell squeeky about AC in another thread. But until he understands that it isn't about "smoothing" DC - he will probably not get it.

It will come to him. All we need is some patience - and hope that he doesn't try electrolytic capacitors... sad

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Blinking Lights

Tangent alert:

"Capacitor assisted starting" of large AC motors was a well known (and thankfully dying) trick of industry in some circles. By "correcting" the poor PF at start-up in a source limited situation, technically more of the available current can be applied to creating torque. The problem is, for it to be effective the capacitors must be sized based on the no-load PF of the motor, often as low as .2-.3. That means that as soon as the motor gets to about 70-80% speed, you are now OVER correcting and can create massive other problems. So capacitor assisted starting has always been a challenge in that you must be capable of detecting motor acceleration and then disconnecting the start-assist caps before you create a voltage surge. That means an added contactor for the capacitors (with capacitor ratings), and some sort of speed detection on the motor shaft, then a control system to deal with it. All in all, compared to other less complicated methods of starting (because remember you STILL need a starter!), it just isn't worth it. I have seen several applications (whole log chippers for the paper industry) where people have attempted to do it on the cheap with timing alone. They all ended in damaged equipment, followed by removal of the caps and associated controls then replacement with something more conventional, such as a soft starter. So it ultimately cost them MORE than just doing it right the first time.

"Will work for (the memory of) salami"

RE: Blinking Lights

It's not only that the capacitor doesn't "store" anything, bringing the capacitor in first will cause a voltage rise. Say you add enough capacitor to correct a 10% voltage dip when the motor is started. Connecting the capacitor first would cause a 10% voltage rise and then the voltage would drop back to nominal when the motor was started. So, you still cause a voltage flicker because the voltage suddenly jumped by 5% or 10% instead of dipping by 5% or 10%.

Besides, the paper was misread anyways because it does not say to energize the capacitors first. In fact, the control scheme wiring they show uses an auxilary contact from the motor starter to energize the capacitors. Here is the quote from the paper.

"The second requirement for a Capstart installation is a control device to energize the capacitors the instant the motor begins to start and de-energize them once the motor reaches full speed."

Capacitor assist works quite well with a soft-starter. You can ramp the current and sequence the capacitor energizing to stay within a certain voltage window. A device to detect speed for dropping the capacitors out is required. But, the cost is very similar to a VFD, which mostly makes it pointless to do.

For this application I'd recommend trying a 1-phase soft-starter with a very short ramp time. It will remove the sudden transient so even though the voltage still dips, it dips over a longer period of time and I doubt anyone would notice it.

I suppose you could also try a zero-crossing solid-state relay. That might lower the flicker enough you can't see it.

RE: Blinking Lights

While we are at it - why not try a KUSA start? It is simple and it *might* work. In fact, it works quite well in many instances. I will try that next in my "series of experiments".

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Blinking Lights

(OP)
I found out the manufacturer and type of Power Quality Meter used by the Power Comapany, and their analysis software is free to download. So I requested the PQM file for my house and they said they need to check with the Legal Department to see if they can send me the file showing the PQ of the electricity I purchased. Geeeeeeez. Was hoping to share the waveforms with the group.

OK i'll bite, What is a KUSA start?

RE: Blinking Lights

KUSA is a German acronym for Kurzschlussläufersanftanlauf-Schaltung. It's essentially a Primary Resistor starting scheme. A resistor is placed in series with the motor winding when first energized, then shorted out to get full power. A "poor man's" soft starter, but very simple. When I was with K-M, we built them with the resistor on just one phase of a 3 phase starter, it was VERY cheap compared to even a regular PR starter. Didn't always work though, the starting torque is very low and the 3 phase motor currents are very unbalanced, so you don't want to use it on anything that has a duty cycle of more than a few times per hour, or per day if it is a large motor.

"Will work for (the memory of) salami"

RE: Blinking Lights

Yes, Jeff is right. I don't know if a scroll compressor has a large starting torque. If it has that, it will not work with a KUSA starter.

Why did I at all mention that? Mostly because this thread and its daughter threads have turned into a discussion that seems to cover every aspect on motor starting. But also because the KUSA start leaves one phase voltage more or less unaffected. If you put your lights on that phase, the pesky blinking may go away.

Still, I will do a small scale test. Curious myself...

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Blinking Lights

A scroll compressor is probably the only compressor you might get away with that on. Why not use a double one so all phases remain balanced?

Keith Cress
kcress - http://www.flaminsystems.com

RE: Blinking Lights

Smoked! Blame yourself - measurements started. OK it is getting late. Tomorrow...

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Blinking Lights

I'm pretty sure the motor in question is single phase so how exactly are you going to install a resistor on only 1 or 2 of the phases????

RE: Blinking Lights

I'm somewhat surprised this thread has generated so much interest and commentary. This is a 200 A residential service (single-phase) and the motor is pulling 120 A locked rotor. There will be flicker. It would be shocking if there were not. The OP needs to accept that, replace the single-phase motor with a three-phase and start from an AFD, or pay for separate service.

RE: Blinking Lights

@ LionelHutz

Are you sure - or just pretty sure?

I wasn't aware that it could be a single phase motor. Sounds awfully impractical. Why does one do that?

OK, I have visited the US many times and everytime I've seen poles bending over from transformers with 4160 V in and single phase out. But very often there are three "buckets" - so three-phase seems to be available.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Blinking Lights

(OP)
Just because it is a 200A service with a 120A motor start current Does Not mean there must be flicker.

Thanks to all who have parcipated in this post, I have learned alot.

RE: Blinking Lights

(OP)
@Skogsgurra

This is a single phase motor. This is a residential area and single phase is all that is available on the pole.

RE: Blinking Lights

Quote:

Just because it is a 200A service with a 120A motor start current Does Not mean there must be flicker.

Based on what?

Increased current creates additional voltage drop in the transformer and conductors. If the voltage drop is great enough there will be perceptible flicker. In theory, the voltage drop could be reduced to levels that are not noticeable by installing much larger conductors and a larger service transformer. In practice, a "200 A" utility service means you have a 200 A main breaker. It does not tell you the size of the utility's transformer, the transformer loading, or the impedance of the system up to your service panel. For virtually any standard residential service, an impact load of 120 A is going to create some flicker.

RE: Blinking Lights

(OP)
Quote

Increased current creates additional voltage drop in the transformer and conductors. If the voltage drop is great enough there will be perceptible flicker. In theory, the voltage drop could be reduced to levels that are not noticeable by installing much larger conductors and a larger service transformer.


Agreed


Quote

In practice, a "200 A" utility service means you have a 200 A main breaker. It does not tell you the size of the utility's transformer, the transformer loading, or the impedance of the system up to your service panel.


Agreed



Quote
For virtually any standard residential service, an impact load of 120 A is going to create some flicker.

Key words, "any standard residential service". I specifically submitted my load study to the Power Co. at the time of my service request showing my itemized loads steady state ( 167A )and the largest STARTING currrent load (AC #1 5 Ton, 120A.) Further the Power Company standards state Momentary start up loads up to 150A are acceptable. It appears the Power Company installed a "standard service".

But what this thread is really about was why capacitors added could or could not solve the transient voltage dip causing the blinking lights, and if they couldn't that the only solution is changes on the Power Company Side, as you describe.

RE: Blinking Lights

Skogs; In the U.S. (sadly) it's generally not allowed to have 3 phases delivered to single family residences.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Blinking Lights

I'm sorry you are unhappy with the situation, but "acceptable" to the Power Company just means that your inrush won't be bothering other customers, not that you will never experience flicker. If you can get your neighbors to start complaining, you might get somewhere.

Flicker is a problem because it bothers people, not because it represents a safety issue or causes any damage to equipment.

I'm not sure that the Power company is going to do much if you are only one complaining, since you are the one creating the flicker. Not unless you are willing to pay for the solution. I actually think the adjustable frequency drive and a three-phase motor is going to be the most cost-effective solution.

Also, FWIW, when a homeowner or contractor provides a load estimate to the utility, they will typically assume that the actual peak load will be about 50% of the calculated total, based on long experience. Utilties do not follow the NEC when sizing transformer or feeders.

Best of luck.

Dave

RE: Blinking Lights

(OP)
I contacted my neighbors and they are not experiencing flicker. So I'm a lone wolf here. Don't see how I could change my motor in the carrier system condensing unit.

RE: Blinking Lights

As I said, Smoked - sounds awfully impractical.

I have a three-phase 400 V 25 A incoming line. 230 V line-neutral. Quite happy with that.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Blinking Lights

marksta; Sorry you have this issue. I know things like this can be grating.

The solutions i see are varied:

1) Reserve yourself to ignore it.

2) Install modern lighting instead of archaic flicker prone incandescents.

3) If a particular appliance is bothered by it get a UPS to run just it. (I once had a computer in a tannery that would reboot every time a leather scissor table's hydraulic motor pack started. Ultimately the solution was a small UPS for the computer. Every time the button was pushed on the table the UPS beeped and kept the comp happily running.)

4) As Skogs is checking, work up an inrush limiter KUSA that provides just barely enough resistance to the starting compressor as to minimize the flicker.

5) Put in an equal size unloaded motor to the compressor's motor that you start first. It will store kinetic energy locally (on the condenser unit's end of the supply line.) Then when the compressor starts the already spinning motor will 'generate' to supply energy into the voltage drop.

6) Switch the compressor out for a three phase unit. Use an oversized VFD to convert your single phase power into 3 phase power. This can eliminate ALL flicker.

Personally I'd probably go with #2. A buddy just dropped his power bill $20/month by switching all his incandescent bulbs out for LEDs.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Blinking Lights

Sorry - I misread your first post - I thought you had some type of air compressor. You're right - a retrofit would not be easy. You might check with Carrier to see if they have a unit with a soft-start or AFD. If these neighbors are on the same transformer secondary, that indicates a lot of the voltage drop is in your service cables. Increasing the size of those should not be outrageously expensive.

If you're interested, there is quite a bit of information on line regarding flicker. Unfortunately even small levels of voltage fluctuation can cause noticeable flicker. Maybe the link below will be of use if you haven't done more reading than you want on flicker:

https://www.pacificpower.net/content/dam/pacific_p...

RE: Blinking Lights

(OP)

Installed a room with LED lamps, and They Do Not Flicker.

If I ever get the wave forms from the Power Company I will post for general interest.

thanks.

RE: Blinking Lights

That's what itsmoked suggested. If he or others helped you, consider pressing the like button to vote them a little purple star

=====================================
(2B)+(2B)' ?

RE: Blinking Lights

Look on the bright side. If you are in Africa and the lights flicker, it means the electricity is still on!
Thanks I have learnt a lot. For me, cables and connections. There is a high impendance somewhere.

RE: Blinking Lights

Hi folks,

It is a very long thread. I have just read some part of it.

For those who have followed the discussion I wonder if there is something in the thread about reducing flicker by just applying series capacitors.
The capacitive reactance of the series capacitor nullifies the inductive reactace of the feeder reducing the voltage drop due to the compressor operation at the point on which the lamp is connected. So the flicker will be reduced.

Best Regards,

Herivelto S. Bronzeado
Brasília, Brazil
http://www.linkedin.com/profile/view?id=46319837&a...

RE: Blinking Lights

Herivelto,

I think that's the basis of the 'hard start kit' mentioned earlier, but didn't make much difference in this case.

RE: Blinking Lights

(OP)
The hard start kit puts a capacitor across the line, not in series.

RE: Blinking Lights

My understanding is that a hard start kit switches in more capacitance in parallel with the start capacitor, which is in series with a start winding but not the run winding. Most of the discussion above seems to be about capacitors across the line but in many cases the comments are not explicitly clear or seem contradictory. So I think Bronzeado's point has not yet been addressed.

RE: Blinking Lights

Agreed, I didn't read Herivelto's post correctly. blush

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