Worldly Compliance Experts, We are planning to incorporate an Intentional Radiator into an existing product (fuel dispenser) which is currently classified as a Class A Unintentional Radiator. The Intentional Radiator is a seperate (one of many) card cage subassembly with it's own power supply. The dispenser is typically powered by a single phase 120V branch circuit, and distributes the 120V to each subassembly via an internal wiring harness, similar to a rack mounted full of gear.
While the FCC Rules pertaining to radiated emissions are quite clear, the Conducted Rules, and how to apply them are causing me some grief. Section 15.31(h) indicates that all of the devices in the system must be functioning during testing. Section 15.31 (k) states that each device must comply with it's own specific standard(s). To meet both of these requirements would entail measuring the Intentional Radiator's conducted emissions individually via a dedicated AC line cord, outside of the (dispenser)enclosure (intentional radiator must meet "Class B" conducted limits). This type of DUT configuration is not representative of the actual installation. I am seeing some large differences in the conducted emissions levels depending on how AC power is delivered to the Intentional Radiator (internally vs. externally powered). Has anyone encountered a similar situation with a "composite system"? Any words of wisdom about how to test such a combination? Thanks in advance, Bob Sykes Gilbarco Inc. [email protected]
