Topic: Program rapid start fluorescent lights. Power disturbance tolerance between ballasts

User: Electric-Light, Location: Durham, NC

Asked on: Saturday, April 2, 2011 at 4:45 am EDT
Answered on: Tuesday, May 14, 2024 at 3:39 am EDT

Question: Each ballast is different. The difference in its tolerance to line dip can mean very angry customer vs not even getting noticed.The best do not flicker at all or much with power disturbance.Better ones just flickerWorst ones reboot.Rebooting is a problem unique to programmed start, because the cycle takes about a whole second and if it happened every time th ere is a disturbance, it is very annoying to the occupants.I've found that some programmed rapid start ballasts are very sensitive to sudden line dip even if it doesn't dip below the rated range while others are very tolerant even those from the same brand.Incandescent and fluorescent will flicker in response to sudden change in power (the more technical phrasing is high -dv/dt). Some programmed start ballast will reboot due to high -dv/dt if the magnitude of change is within tolerance and this means that it will go out for about a second.If the permissible voltage range is +/- 12v and you have 120vrms nominal and a sudden loading causes the voltage to drop to 114vrms in one cycle and lasts a few cycles, you have a dv/dt of -360vrms/s (assuming 60Hz). This can happen when thyristor controlled loads are operated.Instant start ballasts and incandescent lights do not suffer beyond visual nuisance.Sometimes the spec sheets do not tell you anything about serious vulnerability.Products tested are:Incandescent and instant start system:visible flickeringSylvania QTP2x32T8/UNV PSNDid not produce any noticeable response caused by laser printer fuser cycling on the same circuit.http://assets.sylvania.com/assets/D...221).d9619c4c-3ef6-4cf5-ab15-6c9cf4fa3145.pdfThe newer QHE2x32T8/UNV PSN, premium efficiency model. Despite the fact it offers UL CC rated arc limitation, striation reduction circuitry and parallel operation, subjected to the same line dip, this thing will reboot.It offers a saving of 3.4%(120v)/1.8%(277v) for 2 lamp model and 6%(120v)/4.5%(277v) on 4 lamp model.Even though parallel operation allow working lamps to remain lit in the event of a failed lamp within a fixture and significant power saving for the 4 lamp model are lucrative, the reboot vulnerability far outweighs the benefits unless they won't experience power sags.http://assets.sylvania.com/assets/D...218).2d59f1d4-f342-4187-868f-a209d1cb82a7.pdfThe difference between the old model and the new high efficiency model is that unnoticeable on old model vs one second rebooting whenever there is a disturbance on lighting bus caused by across the line or VSD elevators, compressor, high inertia HVAC fan, or large photocopy machines.