Jump to content
Find Professionals    Deals    Get Quotations   Portfolios
Sign in to follow this  
shibumi

Stray Current Causing Lights To Flicker On 2-Way Circuits

Recommended Posts

Hi fellows. I've track lights installed & controlled on a 2-way circuit. Observed that my light (only connect 1 unit * 3-watt track lamp for testing) is flickering even when the switch (es) are off. Repeated the test with alternative track lamps (however, always 1 unit per test) with the same observation. My electrician says the flickering is due to the stray current always present in the circuit of 2-way circuits regardless of them being turned on/off.


I'm not entirely convinced. I'm seeking feedback from users with track light systems controlled by 2-way switches. Do you observe this? What wattage are each of your track lamp? Do you observe this when only 1 lamp is left connected on your entire track? Do let me know. Much appreciated.


N.B. My "2-way" circuit refers to a single track being able to be powered on/off via 2 physical switches.

 

Share this post


Link to post
Share on other sites
Looking for good contractors? Click here for your request
Hi fellows. I've track lights installed & controlled on a 2-way circuit. Observed that my light (only connect 1 unit * 3-watt track lamp for testing) is flickering even when the switch (es) are off. Repeated the test with alternative track lamps (however, always 1 unit per test) with the same observation. My electrician says the flickering is due to the stray current always present in the circuit of 2-way circuits regardless of them being turned on/off.
I'm not entirely convinced. I'm seeking feedback from users with track light systems controlled by 2-way switches. Do you observe this? What wattage are each of your track lamp? Do you observe this when only 1 lamp is left connected on your entire track? Do let me know. Much appreciated.
N.B. My "2-way" circuit refers to a single track being able to be powered on/off via 2 physical switches.

Phantom voltage unlikely to energise lamp.

Are your switches dimmable type or just plain on/off?

 

Share this post


Link to post
Share on other sites

To my knowledge, by normal wiring means the lights should not light up when they are switched off.

Might have a electrical hazard somewhere in your system, you probably should get someone to check it out...

 

Share this post


Link to post
Share on other sites

Phantom voltage unlikely to energise lamp.

Are your switches dimmable type or just plain on/off?

My switches are non-dimmable. Anyway, here's the video:

https://www.youtube.com/watch?v=7531-6wqZF0

& I stressed again 3 points:

  • I'd tried with a few other 3-watt lamps (1 at a time of course); the problem is consistent
  • I'd tried with 1 7-watt lamp; the problem is able to be re-produced, although the interval between flickering is longer
  • I'd pass my own 3-watt lamp to my friend's place, who's also using 2-way switches on his track; no problem.

I still dunno what's going on.

& I still find it unbelievable that my electrician can tell me a little bit of stray current in 2-way circuits (despite being switched off) is normal.

 

Share this post


Link to post
Share on other sites

From the description in the youtube video, there is indeed a possibility that stray voltage in the strapper wires cause the light to flicker. Strapper wires are the two wires between the 2 way switches. Do you know if the strapper wires are individual single conductor or the strapper wires are bounded together (flat twin)? If they are bounded together, it makes it worse. If they are not bounded together, one way to conclusively prove that it is/is not stray voltage is by separating the 2 strapper wires. You can do this temporarily by opening up the trunking/casing and separate them. However, please switch off the circuit breaker first. By separate, I mean do not let the two strapped wires come close to each other. Separate them as far as possible. Also, for this to be conclusive, there must be no other phase (live) wire next to the strapper wires or the wire connected to the light.

 

Share this post


Link to post
Share on other sites

So I went down to did further troubleshooting today & discover something peculiar.

There is another light in the (living room) area. I observe that, the flickering (in my track light) only occurs when this other lamp is powered on!? The tracks & this standalone lamp do not share the same switches; they each have their own individual physical switches (they are all controlled by 2-way switches, if this fact matters). However, as you can see in the video, their switches are extremely close together, i.e. essentially in the same cluster. The following video demonstrates today's observation (pay close attention to which switch I turn on/off):

https://www.youtube.com/watch?v=AIAnTgZeJuM

Does this suggest somehow the 2 switches are short-circuiting/leaking to one another?

From the description in the youtube video, there is indeed a possibility that stray voltage in the strapper wires cause the light to flicker. Strapper wires are the two wires between the 2 way switches. Do you know if the strapper wires are individual single conductor or the strapper wires are bounded together (flat twin)? If they are bounded together, it makes it worse. If they are not bounded together, one way to conclusively prove that it is/is not stray voltage is by separating the 2 strapper wires. You can do this temporarily by opening up the trunking/casing and separate them. However, please switch off the circuit breaker first. By separate, I mean do not let the two strapped wires come close to each other. Separate them as far as possible. Also, for this to be conclusive, there must be no other phase (live) wire next to the strapper wires or the wire connected to the light.

@Pelect

By any chance are you an electrician for hire? I appreciate your technical input but lacking the proper skills, I dare out execute the instructed troubleshooting by myself. If you are available to assist in a more direct manner, do let me know.

 

Share this post


Link to post
Share on other sites

Interesting observation.

However, the first video shows the flickering without powering on the plastic bag light. (The whole scene is dark).

If the flickering only occurs with powering the plastic bag light, then there are two things to look at:

1. The proximity of the strapper wires, including the ones from the plastic bag light. This might be difficult for you to trace since you have more than 1 set of strappers and if the wires are concealed.

2. The plastic bag light and the track lights share a common neutral. Could you turn off breaker switch for plastic bag light and see if the track lights can be turned on? This is to determine if both sets of lights are on the same circuit or different circuit.

 

Share this post


Link to post
Share on other sites

Interesting observation.

However, the first video shows the flickering without powering on the plastic bag light. (The whole scene is dark).

If the flickering only occurs with powering the plastic bag light, then there are two things to look at...

Very observant! However, I can't recall now, but it may be due to me standing very close to the track light in the 1st video (& hence blocking any form of illumination from the "plastic bag light"; which will be way behind me); or it is possible that I did not place any light bulb in the plastic bag light in the first video.

Let's assume with 1 of the above explanation is valid.

...1. The proximity of the strapper wires, including the ones from the plastic bag light. This might be difficult for you to trace since you have more than 1 set of strappers and if the wires are concealed...

May I know what strapper wires are, & how do the local variants resemble? I may have an old image showing the wires before the switches went up...let me go dig...

...2. The plastic bag light and the track lights share a common neutral. Could you turn off breaker switch for plastic bag light and see if the track lights can be turned on? This is to determine if both sets of lights are on the same circuit or different circuit.

That I think I can do. Will update here.

...The plastic bag light...

Nice term!

 

Share this post


Link to post
Share on other sites

The bunch of wires on the left looks more like they are for a power socket.

Anyway, I mock up a quick set up to show how the wires are connected in a two way switch. This is one way of connecting and is not the only way.

9F754B5D-BA2B-4569-8D80-1F8D8F6A187B_zps

In a 2 way switch, there are 3 terminals. The centre terminal is usually the common or C terminal.

The brown live wire on the left connects to the common terminal.

The 2 yellow wires connect in between the 2 way switches. The yellow wires are called strappers.

Another wire, the red wire, connects the lamp to the 2 way switch on the right.

Finally, the blue neutral wire completes the circuit.

Depending on the switch position, one of the 2 yellow wires will be connected to the brown live wire.

When one yellow is live, the other yellow will be open.

The closer the 2 yellow wires are and the longer the 2 yellow wires are, the greater the stray voltage.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×