Moving collection touch points group and conversion touch points group in the of moving collection touch points on, due to connected Shi touch points back jumped times less and touch points burn corrosion Hou compensation volume big, its load capacity and contact reliability more moving broken touch points group and conversion touch points group in the of moving broken touch points on to high, machine line can through on touch points location appropriate adjustment, as more with moving collection touch points. Depending on the size of load capacity and load (resistive, inductive, capacitive, light load and motor load) parameter is very important. Consider switching loads smaller than switching load big reliable is not correct, in General, relay switching under load at rated voltage and current is greater than the rated current of 100mA, less than 75% the best. Current less than 100mA will increase contact point carbon, decline in reliability, 100mA current test, is domestic and international professional standards of relay production factory conditions and the level of the content. Since relays do not in general have low level switching capability, used switches below 50mV, 50 μA load relay orders, users must be marked.