TP-6126 8/02
1
Section 1 Product Description
Section 1 Product Description
1.1 Purpose
An automatic transfer switch (ATS) transfers electrical
loads from a normal (preferred) source of electrical
power to an emergency (standby) source when the
normal source falls outside the acceptable electrical
parameters.
When the normal (preferred) source fails, the ATS
signals the emergency (standby) source generator set
to start. When the emergency (standby) source reaches
acceptable levels and stabilizes, the ATS transfers the
load from the normal (preferred) source to the
emergency (standby) source. The ATS continuously
monitors the normal (preferred) source and transfers
the load back when the normal (preferred) source
returns and stabilizes. After transferring the load back to
the normal (preferred) source, the ATS removes the
generator start signal, allowing the generator set to shut
down.
Figure 1-1 shows a typical installation block diagram.
1.2 Nameplate
A nameplate attached to the controller cover on the
inside of the enclosure door includes a model
designation, a serial number, ratings, and other
information about the transfer switch. See Figure 1-2.
Copy the model designation, serial number, and
accessory information from the nameplate to the spaces
provided in the Product Identification Information
section inside the front cover of this manual for use when
requesting service or parts.
Copy the model
designation into the spaces in Section 1.3 and use the
accompanying chart to interpret the model designation.
The serial number is also shown on a label inside the
transfer switch enclosure.
Power
Switching
Device
To Load
Automatic Transfer Switch
Electrical
Controls
Normal
(Utility)
Power
Emergency
(Generator)
Power
Generator
Start Generator
TS-003
Figure 1-1
Typical ATS Block Diagram
GM21291
1
2
3
1. Model designation
2. Serial number
3. Factory-installed accessory numbers
Figure 1-2
Typical Transfer Switch Nameplate
