A 6 channel SmartBar or SmartModule requires 3-phase power and is being fed by 3 individually breakered circuits, rather than a single 3-pole breaker.
If you are running a SmartBar or SmartModule that requires 3 phase power, make certain that the supply or feed lines are running through a single 3-pole breaker, not 3 individually breakered power feeds. There are a few reasons for utilizing the 3-pole breaker.
The first is the most important: this is a safety issue. The National Electrical Code dictates that when supplying power to 3-phase devices, a single 3-pole breaker must be utilized. In everyday terms: imagine needing to service the unit and turning power off to the Smart product. If the supply voltage is fed through a single breaker (a single 3-pole breaker, in this case) you can be confident all power has been shut off and it is safe to proceed. If the unit is fed from 3 individual breakers, an unsuspecting colleague could "shut off the power" by switching a single circuit breaker. Most people are used to this convention. It is the same with your dryer or stove--a single breaker that you switch--not multiple breakers located in separate locations on the panel.
Now as for the SmartBar or SmartModule not dimming properly, there are issues caused by using 3 individually breakered supplies. Unless the 3 breakers are all turned on simultaneously, the SmartBar will not have a chance to compare the sine waves from all feeds to determine the proper operating parameters. This will adversely affect the dimming.
Additionally, the power cable for the 3-phase SmartBars and SmartModules has conductors sized for three phase operation. If wiring into three separate circuits that aren't all on differing phases of the same feed, it is possible to overload the current carrying capacity of the neutral conductor causing the wire to heat up and possibly fail.
As you can see, ETC recommends using a single 3-phase breakered feed for a number of reasons. If you have any questions regarding this topic, please feel free to call ETC Technical Support at 800-688-4116.