Separating LED's from Fans

[Curtiszeph]

The company I used to work for had always had us run a separate circuit for the LED general lighting and a separate circuit for ceiling fans and/or bathroom exhaust fans. The reasoning behind it was to eliminate the chance for inductive kick back and the LED flickering on and off with the fan straight from the rough in/planning stage. Have had my own business for the last four years and do it that same way just because that's how I was taught, but was talking to some buddies the other day and they thought I was crazy for doing that. Was curious if this is standard practice out there or if my old company (and myself by extension) has just been going unnecessarily above and beyond on the install? Thank you.

 

[Sberry]

Everyone has their spin and here is mine. I run 14 for the lights and fans and 12 for the recepts and run the power daisey chained or from a Jbox depending on old/new etc (this is general) but switchbox to switchbox then use 3 conductor to every fixture box or ceiling box incl fan/light and I cap the black and its live or in the case of the light fan feeding from 2 switches. Some places elevate the switching for scones vanity/special so its not confused for general lights among a switchbank, its another hole in the wall but reduces a lot of confusion. I have tapped a couple things for power beyond and while I dont start out with anything except a 59 cent switch a guy can buy a double switch if it comes to it if the wire is in there and it is so short and 1 small conductor already in a cable and super for someone always changing their mind. super easy to add automatic control if there is a wire.

 

[Sberry]

I dont run another circuit for an approved fixture. Now the N is required at swtich boxes, that is great so I dont use switchloops but I add another wire to the fixtures which is where I would want it for automatic or the potential to switch it again or extend the circuit. I want all that on one circuit vs different feeds from different circuits.

 

[Little Bill]

The company I used to work for had always had us run a separate circuit for the LED general lighting and a separate circuit for ceiling fans and/or bathroom exhaust fans. The reasoning behind it was to eliminate the chance for inductive kick back and the LED flickering on and off with the fan straight from the rough in/planning stage. Have had my own business for the last four years and do it that same way just because that's how I was taught, but was talking to some buddies the other day and they thought I was crazy for doing that. Was curious if this is standard practice out there or if my old company (and myself by extension) has just been going unnecessarily above and beyond on the install? Thank you.

I don't do it that way but I did have a problem on the last house I wired with a LED light flickering when the bath fan was turned on or off. I guess it depends on the LED and electrical noise from the fan. Might not be a bad idea to run the fan off a receptacle circuit. I just hate to have an extra wire in the 2 or 3 gang box. Also, might be confusing to someone working on a switch thinking the breaker is off but didn't realize there was two circuits in a bath light switch box.

 

[kwired]

I have frequently been putting fan on with any light over tub or shower, but usually a separate run to each from switch box just in case they want to change what comes on with what. May or may not be on with bath receptacle circuit depending on circumstances.

 

[Curtiszeph]

Thank you for the replies, seems like it is not common to run a separate circuit for the fans. Interesting.

 

[James L]

Of course it's not common to run a dedicated circuit for a fan. What do you do in the case of a ceiling fan with light? Do those get a dedicated multi wire branch circuit? They share the neutral.

I'm doing a finish right now, in a master bathroom, which has LED disk and separate bath fan. There's a constant flutter in the disk light.

 

[Little Bill]

Of course it's not common to run a dedicated circuit for a fan. What do you do in the case of a ceiling fan with light? Do those get a dedicated multi wire branch circuit? They share the neutral.

I'm doing a finish right now, in a master bathroom, which has LED disk and separate bath fan. There's a constant flutter in the disk light.

Is the LED on a dimmer?

 

[James L]

Is the LED on a dimmer?

No, just the combination of that particular disk light with that particular bath fan. Every time I pair those two "cheapest available" options, the disk flutters.

I have used that fan together with other LED lights, with no issues.

I have used that LED light together with other fans, with no issues

Here's the rub. They don't want to spend money to upgrade either the light or the fan, they won't want to pay to power them from different circuits.

 

[Little Bill]

No, just the combination of that particular disk light with that particular bath fan. Every time I pair those two "cheapest available" options, the disk flutters.

I have used that fan together with other LED lights, with no issues.

I have used that LED light together with other fans, with no issues

Here's the rub. They don't want to spend money to upgrade either the light or the fan, they won't want to pay to power them from different circuits.

I asked because I've had luck with adding an MLC (minimum load capacitor) to stop the flickering. I had one last year that wasn't on a dimmer. The LED would flash/flicker when the fan was turned on or off. The MLC didn't help with that. Customer didn't want to do anything either since it only happened when turning on/off and only for a second or two.

 

[Curtiszeph]

Of course it's not common to run a dedicated circuit for a fan. What do you do in the case of a ceiling fan with light? Do those get a dedicated multi wire branch circuit? They share the neutral.

I'm doing a finish right now, in a master bathroom, which has LED disk and separate bath fan. There's a constant flutter in the disk light.

Yeah we don't run a dedicated circuit to every fan, but catch multiple fans on one circuit and multiple rooms on a second circuit for the lights. If the fan had a light kit the of course its powered by the fan circuit. I guess this has been our practice out of an abundance of caution to avoid the exact issue you're having in that master bath. I'll try it the cheaper/easier/quicker way for a bit and see if I get many headaches. Thanks.

 

[James L]

I'll try it the cheaper/easier/quicker way for a bit and see if I get many headaches. Thanks.

It's not simply that it's Cheaper, easier, and quicker. It's just that we are facing increasing incompatibility with more and more electronic lighting and controls we install. And that's the key, we are installing. We don't manufacture these products.

But I wasn't trying to impose on you to do it a particular way, just stating that it's not common.

If you have found a method which gives you better peace of mind and less call backs, then by all means proceed in that way.

I take a "better for me" approach on several things which cost more and take longer when i'm wiring houses. My choice, and I have my reasons.

 

[Flicker Index]

Someone posted on this forum a dummy load thing used to stabilize dimmer. I think it's just a capacitor intended to be used for this application.
That across the fan wires might work just fine. https://byjasco.com/jasco-direct-wi...hten-jasco-and-ge-smart-dimmer-switches-white

Basically, it's a capacitor, but properly rated. A foil capacitor with a series resistor will work just fine, but home brewed device like that wouldn't be code compliant.