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Auto Transfer Switch intelligent

In the circuit:

Km: contactor for main power. ŌĞƌ ǁŽƌŬŝŶŐ ƚŚĞ ŐĞŶĞƌĂƚŽƌ ĚŽŶ͛ƚ ŐŝǀĞ ƵƐ ƌĞŐ-
Kg: contactor for electrical generator. ƵůĂƚĞ ŽƵƚƉƵƚ ǀŽůƚĂŐĞ ĂŌĞƌ ƐƚĂƌƟŶŐ ĚŝƌĞĐƚůLJ ďƵƚ
O-U Voltage Relay: put in parallel with the elec- ĂŌĞƌ ŵĂŶLJ ƐĞĐŽŶĚ ďĞ ƌĞŐƵůĂƚĞ ŽƵƚƉƵƚ ǀŽůƚĂŐĞ
trical generator to be sure from output voltage from the generator , then the O-U Voltage relay
value form generator. closed its open contact which connected with
WŚͲƐ ZĞůĂLJ͗ ďĞ ƐƵƌĞ ĨƌŽŵ ƚŚĞ ŵĂŝŶ ĞůĞĐƚƌŝĐĂů ĐƵƌ- ĐŽŝů ŽĨ ƌĞůĂLJ ĐĂůůĞĚ <Ϯ ƐŽ ƚŚĞ ŬϮ ƐƚĂƌƟŶŐ ƚŽ ǁŽƌŬ
rent and its regularity, in case of be outage or in and closed the open contact K2 which con-
case of don’t be regulate it send signal to do the ŶĞĐƚĞĚ ǁŝƚŚ ƐĞůĞĐƚŽƌ ^ϭ ǁŚŝĐŚ ďĞ ŽŶ ĂƵƚŽŵĂƟĐ
conversion process to main power. ƉŽƐŝƟŽŶ ƐŽ ƚŚĞ ƟŵĞƌ ƐƚĂƌƚ ǁŽƌŬŝŶŐ dϯ ͕ ĂŌĞƌ
D ͗ ŝƚ͛Ɛ ĐĂůůĞĚ DŽůĚĞĚ ĐĂƐĞ ĐŝƌĐƵŝƚ ďƌĞĂŬĞƌ͕ ŝƚ ƉĂƐƐ ƚŚĞ ƐĞƫŶŐ ƟŵĞ ŵĂLJ ďĞ ϭϬ ƐĞĐ ͕ ƚŚĞ ŽƉĞŶ
been connected before the load to save it from contact of the will be closed to start working
over electrical current or the short circuit. the contactor coil Kg and the generator start to
,Žǁ ĂƌĞ ǁŽƌŬŝŶŐ ƚŚĞ ŐĞŶĞƌĂƚŽƌ͗ feed the loads .

In case of the main power:

When the main power came back and be regulate selector S1 and it’s a reason to start working two
, the phase sequence and failure relay closed its ƟŵĞƌƐ dϭ ͕ dϮ ǁŚŝĐŚ dϭ ďĞ ƐĞƚ ŽŶ ƟŵĞ ůĞƐƐ ƚŚĂŶ ƚŚĞ
open contact and start working the relay coil K1 ƟŵĞ ŽĨ dϮ ͘
which this relay do that : dŚĞ dϭ ƟŵĞƌ ĂŌĞƌ ƉĂƐƐ ƚŚĞ ƐĞƫŶŐ ƟŵĞ͕ ĚŝƐĐŽŶŶĞĐƚ
Open its closed contact which connected with gen- the Kg (disconnect the generator feeding) and T2
erator to disconnect it. ĂŌĞƌ ƉĂƐƐ ŝƚƐ ƐĞƫŶŐ ƟŵĞ ƐƚĂƌƚ <ŵ ŝƚƐ ǁŽƌŬŝŶŐ ƐŽ
ŶĚ ĐůŽƐĞĚ ŝƚƐ ŽƉĞŶ ĐŽŶƚĂĐƚ ǁŚŝĐŚ ĐŽŶŶĞĐƚĞĚ ǁŝƚŚ the main power connected.

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