Sorry for the thread bump, but I've had similar problems. One long track of about 20 ceiling fans, in a home improvement store. Moved the track to another phase, but that only helped briefly. We won't allow more than 12 amps on a 20 amp circuit. Voltage hot to neutral, hot to ground, hot to steel rafter all read 120; neutral to ground and neutral to alternate ground read zero. Switched every bulb, still flickered. Took an entirely different batch of bulbs off the shelf, still flickered. Called the manufacturer, no help.

EDIT Not a single bulb in any of the fans flickered when plugged into a receptacle under a sales register. Possible energy management issue?? The desks run 24/7, the fan display cuts off at close.

 

Sorry for the thread bump, but I've had similar problems. One long track of about 20 ceiling fans, in a home improvement store. Moved the track to another phase, but that only helped briefly. We won't allow more than 12 amps on a 20 amp circuit. Voltage hot to neutral, hot to ground, hot to steel rafter all read 120; neutral to ground and neutral to alternate ground read zero. Switched every bulb, still flickered. Took an entirely different batch of bulbs off the shelf, still flickered. Called the manufacturer, no help.

EDIT Not a single bulb in any of the fans flickered when plugged into a receptacle under a sales register. Possible energy management issue?? The desks run 24/7, the fan display cuts off at close.

How did it look on o'scope or PQA?

Which is controlled how?

 

Most fluorescent lamps flicker to some degree. The most reliable fix is to put some of the fluorescent lights in an area on separate circuits /phases. The lights will still flicker, but if they are on separate phases, the flicker will be at a slightly different time on each phase which "fools" your eyes so it is not noticed. Also, not all CFLs are rated for base up use.

 

Is it on it's own circuit? Shared N's possibly causing this issue..?

 

I'd try to measure the voltage profile for a period of time with a PQA. I have a feeling that a motor load is screwing with the voltage, and the root cause might be a loose tap someplace.

 

Incandescent lamps are just as susceptible to flickering from voltage fluctuations. This is the reason power companies impose rules on its customers in regard to starting large motors, because even a very small sudden voltage change produces enough flicker to generate complaints from other customers.

What do cause CFLs to flicker are solid state controls not designed for non-incandescent loads and harmonic distortion if and only if these CFLs are special power factor corrected versions sometimes endorsed by the PoCo.

When you test the device on an outlet, are you just moving the bulbs, or plugging the entire fixture? Many ceiling fans have solid state control for both the motor and lamps and may not be designed to operate non-incandescent load.

 

makes sense...try taking the HR directly to the panel.

 

Moving entire fans to the receptacle. They are built on a bar that snaps into place on a hanging display cloud. The vendors who built the fans tested each one (they're a seperate company, but work under our supervision and I verified they did it). The motors are connected unless the builder made an error. You might be onto something with the shared neutral idea. The display cloud was wired with two seperate runs of reloc. If unfamiliar with the product, its essentially 12/4 MC. Both runs went back to the same busway but different disconnects for a total of six circuits powering eight tracks. The issue was limited to the B phase, at least until about a week after the job was finished.

No oscope or anything, got a tough enough time getting them to replace cheap drill bits. As the issue was not in the reloc or in the fans/display, the problem was kicked back to the ground up EC. However, I wish I knew how (or if) they fixed it. These jobs for the big box home improvement center comprise 100% of our jobs.

Solid state design for the bulbs? Uh.....its possible three companies and nearly two dozen people overlooked the simplest answer; I know I certainly didn't pay attention to anything like that. I suddenly feel very foolish...