Power limit and power saving circuit

This is a circuit diagram of a power-limited power saver . Close the knife switch QS, the AC contactor KM acts, and the power is sent to the load
through its closed contact KM and the coil of the current relay K.
If the load current does not exceed the set value of 'h, the power supply is normal
. If it exceeds the setting value of ^, K acts, its normally open contact K closes, time
relay KT acts, and its contact KT opens. The KM coil loses power, the normally open contact
KM is disconnected, and the circuit stops receiving power. At the same time, K loses power and K opens, causing KT to lose
power. Due to the power-off delay closing and delay opening contacts , KT goes through a certain delay after power-off
(0.4-0.6s or 0.4-180s adjustable ), KT returns to the initial state, and the circuit
delivers power again. At this time, if the load exceeding the limit has been removed, the device will resume
normal power supply; if the load exceeding the limit has not been removed within the delay time limit, the limiter
will cut off power again until the load drops below the set value. When the power limiting device operates,
the electric bell DL alarm is connected through KT to remind the user to pay attention.