![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
What's the difference between signal wayside safety relay and nomal relay?
A.
signal safety relay use gravity principle.
B.
if safety relay failure ,front contact close.
C.
we can use normal relay to replace safety relay.
D.
safety relay have large volume.
E.
onborad signal equipment can use wayside safety relay.