24V DC control voltages,grounded (earthed) and ground free.grounded (earthed)是不是指24V- ground free指24V+
问题描述:
24V DC control voltages,grounded (earthed) and ground free.
grounded (earthed)是不是指24V-
ground free指24V+
答
grounded是接地吧
窃以为,接地的话不是电势为0了吗?