Rooms that have more than one X-ray generator installed need to have room warning lights that are illuminated when either of the generators is in use. To avoid confusion it is advisable to have the same room warning lights for either unit. There should also be an indication of which unit is in use. The two diagrams attached show the switching arrangements for either a room in which a common isolator controls the supply to both units (Figure 1), or a room where there are separate isolators for each unit (Figure 2).
Figure 1 Room warning light switching when two units are installed in one room, sharing an isolator
Figure 2 Room warning light switching when two units are installed in one room, using separate isolators
The relays should be selected with coils that are compatible with the supply available from the units. The diagrams show the warning lights powered from the normal mains supply, but a low voltage supply may be substituted if this is preferred. Metal light-boxes should be earthed to the ERB for the room. There can be either one ERB serving both units or two cross linked ERBs, one of each of the units.
