Yes there is.
Pick two ISOLATION transformers of the appropriate ratings [voltage and current] to power up each half of the light bar.
Wire up the primaries to share a common neutral and use each wall switch to apply power to one transformer.
The secondaries will have to be wired in SERIES so that HIGH side of the first transformer is connected to the LOW side of the second transformer.
The LOW side of xfmr 1 is connected to circuit A.
The HIGH side of xfmr 1 AND the LOW side of xfmr 2 are both connected to common.
The HIGH side of xfmr 2 is connected to circuit B.
This way, the common of the light bar should not see more current than either side A or side B. This is just like the 120 / 240 Volt single phase house feed.
Obviously the transformers are fed from the same circuit or they MUST be fed from the SAME PHASE!! Verify the output voltages BEFORE you connect them to the lights.
You should get about 14 Volts from circuit A to common and about 14 Volts from circuit B to common AND about 28 Volts from circuit A to circuit B.
Larry
