An Automatic Transfer Switch (ATS) is an electrical switch that automatically transfers a load between two power sources. Some key points: - An ATS is often installed where a backup generator is located so that the generator can provide temporary power if utility power fails. - ATSs can be open transition or closed transition. A softloading transfer switch uses a closed transition type to synchronize and operate onsite generation in parallel with utility power. - A static transfer switch uses power semiconductors like SCRs to rapidly transfer a load between sources within a quarter cycle, protecting loads from interruptions. - Components of an ATS include contactors, circuit breakers, timers, monitoring relays

1. Automatic Transfer Switch
(ATS)

2. What is the ATS
panal ?
is an electrical switch that
switches a load between two
sources.
Some transfer switches are
manual ,
in that an operator effects the
transfer by throwing a
switch,
while others are automatic
and trigger when
they sense one of the sources
has lost or gained power.

3. An Automatic Transfer
Switch (ATS) is often
installed where a
backup
generator is located,
so that the generator
may provide
temporary electrical
power if the utility
source fails.

4. Operation of a transfer switch

5. Types
Open transition Closed transition

6. Soft loading
• A softloading transfer switch
(SLTS) makes use of a CTTS, and
is commonly used to synchronize
and operate
onsite generation in parallel with
utility power, and to transfer loads
between the two sources while
minimizing
voltage or frequency
transients.[3][4][5]
Static transfer switch (STS)
• A static transfer switch uses power
semiconductors such as Silicon-
controlled rectifiers (SCRs) to transfer a
load
between two sources. Because there are
no mechanical moving parts, the
transfer can be completed rapidly,
perhaps within a quartercycle of the
power frequency. Static transfer
switches can be used where reliable and
independent sources of power are
available, and it is necessary to protect
the load from even a few power
frequency cycles interruption time, or
from any surges or sags in the prime
power source

7. Any (ATS)components
• 1- two contactor (with mechanical interlock)
• 2-one MCCB for the main load
• 3-two MCB to control circuit
• 4- three timers (on delay) at least two timers
• 5- over and under voltage relay
• 6- phase sequence and failure relay
• 7-charger to generator battery with over current protection
• 8-two power relay
• 9-four indication lamp –two grean and two red
• 10-selector switch and two push puton normal close and two
normal open