In order to measure accurately the load of electric locomotives and short circuit current, the secondary side of CTs connected with catenary and feeder should be connected in differential mode.
为了准确反映电力机车的负载电流或短路电流，应将接触导线和正馈线上的电流互感器次边差接。
2
In the hot water system a high water tank with solenoid valve controlled water feeder is used to replace the secondary circulating pump.