I don't have either of these products. However, I think that the zone VI compensating timer compensates for fluctuations in output of a cold light as the temeprature of the light source fluctuates. By VCL 4500 I assume you mean the Saunders/LPL which has a dichroic light source. Therefore, the lightsource output does not fluctuate. In other words, you don't need the compensation feature. You should be able to use the timer with the usual connections. I use the RH Designs StopClock Pro.