IB01602078E
For more information visit: www.generac.com
Instruction Booklet
Effective: September 2011
Page
15
40-400A (480/600Vac) ATC-300+ 3-Postion
Contactor Based Transfer Switch
Section 4: Installation and Wiring
4.1 General
Generac ATSs are factory wired and tested. Installation requires
solidly mounting the enclosed unit and connecting power cables
and auxiliary pilot circuits. Physical mounting procedures and
power cable connections are covered in this section. All other
required wiring or electrical connection references are covered in
a separate Customer Wiring Booklet packaged with the ATS.
Locate the wiring schematic, review it, and keep it readily avail-
able for reference purposes during installation and testing. Once
an ATS is properly installed and wired, it should be mechanically
and electrically checked for proper installation and operation.
The procedures for these initial mechanical and electrical checks
are outlined in Section 6 of this instruction manual.
WARNING
BE CERTAIN THAT THE SOLID STEEL DOOR IS PROPERLY
INSTALLED BEFORE THE TRANSFER SWITCH EQUIPMENT IS PUT
INTO SERVICE. THE DOOR PROVIDES PROTECTION FROM DAN-
GEROUS VOLTAGES AT THE LINE AND LOAD TERMINALS WHEN
THE EQUIPMENT IS IN OPERATION. FAILURE TO DO SO COULD
RESULT IN PERSONAL INJURY OR DEATH.
4.2 Mounting Location
Choose a location that offers a flat, rigid mounting surface capa-
ble of supporting the weight of the enclosed ATS equipment.
For standard ATSs, avoid locations that are moist, hot, or dusty.
However, Generac offers optional enclosure designs that can be
used in special environments. If there are any doubts as to a
location’s suitability, discuss them with your Generac representa-
tive.
Check to make certain that there are no pipes, wires, or other
mounting hazards in the immediate mounting area that could cre-
ate a problem.
Carefully remove all packing material from the ATS at the mount-
ing location. Even though an equipment inspection should have
been made when the equipment was received, make another
careful inspection of the enclosure and the enclosed ATS compo-
nents as the packing material is removed and the enclosure read-
ied for mounting. Be especially alert for distorted metal, loose
wires, or damaged components.
4.3 Mounting Procedure
CAUTION
SINCE THE ENCLOSED ATS MUST BE LIFTED INTO PLACE FOR
MOUNTING, BE CERTAIN THAT ADEQUATE RESOURCES ARE
AVAILABLE FOR LIFTING TO AVOID PERSONNEL INJURIES OR
EQUIPMENT DAMAGE.
All equipment enclosures and power panels are of the same
design. Only the overall physical dimensions change. Note that
the enclosure is provided with four teardrop (elongated) mount-
ing holes, two in the top mounting flange and two in the bottom.
Cable entry holes are not part of the enclosure when shipped
from the factory and must be provided in the field, either before
or after mounting the enclosure. Cable access may be from the
top, bottom, and/or side.
CAUTION
EXTREME CARE SHOULD BE TAKEN TO PROTECT THE TRANSFER
SWITCH FROM DRILL CHIPS, FILINGS, AND OTHER CONTAMI-
NANTS WHEN MAKING THE CABLE ENTRY HOLES. EXTREME
CARE SHOULD ALSO BE TAKEN WHEN MOUNTING THE ENCLO-
SURE TO PREVENT COMPONENT DAMAGE OR A FUTURE MAL-
FUNCTION.
Figure 10.Typical (40A-400A) Contactor Based ATS
Equipment (Door Open).
