kick in
lick inは「（直ちに）作動する」というイメージがよく伝わるPVです。（UG）
Fukushima worker accidentally switches off cooling pumps, backup kicks in
The operator of Japan's crippled Fukushima nuclear plant said on Monday that pumps used to inject water to cool damaged reactors were hit by a power failure, but a backup system kicked in immediately.
