If you check the print K & KR should never Electrically be in together. The walking beam is to prevent blowing a main line fuse in event of a mishap. Always make sure there is condenser timing between the two and all the De-Ionizers are over the large contacts. The De-ionizers also prevent blowing main line fuses buy separating the conductible gas (ozone) created buy arcing when AC is used on Carbon to Silver. Never use Silver to Silver contacts on AC. It welds. Then you would need your walking beam. Otis found that out many years ago when contacts on Escalators welded and unit kept running when safety circuits were opened. Above all be safe!