SECTION 1
INSTALLATION
1---1
ASCO 7000 Series Automatic Delayed–Transition
Transfer & Bypass–Isolation Switches (7ADTBs) are
factory wired and tested. Field installation requires
mounting and connection of service cables, and auxiliary
control circuits (if required).
Remove the Shipping Skid
Open the front door and remove the four lag screws (2 in
front, 2 in rear) securing enclosure to the shipping skid.
Supporting Foundation
The supporting foundation for the enclosure must be
level and straight. Refer to the applicable enclosure
outline drawing included with the switch for all mounting
details including door opening space.
If bottom cable entry is used, the foundation must be
prepared so that the conduit stubs are located correctly.
Refer to the enclosure outline drawing for specified area
and location. Provide cable bending space and clearance
to live metal parts. When a concrete floor is poured, use
interlocking conduit spacer caps or a wood or metal
template to maintain proper conduit alignment.
Mounting
Refer to the applicable enclosure outline drawing fur-
nished with this switch and mount the automatic transfer
switch according to details and instructions shown on
diagram.
Line Connections
Refer to the Wiring Diagram provided with the switch.
All wiring must be made in accordance with the National
Electrical Code and local codes.
Do not remove the interphase barriers from the transfer
switch. Always protect the transfer switch, bypass switch,
and isolation contacts and mechanisms from construc-
tion grit and metal chips when cabling.
De–energize the conductors before making any
line or auxiliary circuitry connections. Be sure
that Normal and Emergency line connections
are in proper phase rotation. Place engine gen-
erator starting control in the OFF position. Make
sure engine generator is not in operation.
Testing Power Conductors
Do not connect the power conductors to the transfer
switch until they are tested. Installing power cables in
conduit, cable troughs and ceiling-suspended hangers
often requires considerable force. The pulling of cables
can damage insulation and stretch or break the
conductor’s strands. For this reason, after the cables are
pulled into position, and before they are connected, they
should be tested to verify that they are not defective or
have been damaged during installation.
Protect the switch from construction grit
and metal chips to prevent malfunction or
shortened life of the 7ADTB switch.
Connecting Power Conductors
After the power cables have been tested, connect them to
the appropriate terminal lugs on the bypass switch as
shown on the wiring diagram provided with the switch.
Make sure the lugs provided are suitable for use with the
cables being installed. Standard terminal lugs are solder-
less screw type and will accept the wire sizes listed on the
drawings provided with the 7ADTB. Be careful when
stripping insulation from the cables; avoid nicking or
ringing the conductor. Remove surface oxides from
cables by cleaning with a wire brush. When aluminum
cable is used, apply joint compound to conductors.
Tighten cable lugs to the torque specified on rating label.
Controller Ground
A grounding wire must be connected to the controller’s
lower left mounting stud. Because the controller is
mounted on the enclosure door, a conductive strap must
be used between the enclosure and the door. This
connection provides proper grounding which does not
rely upon the door hinges.
Harnesses
The transfer switch is connected to the left side of the
controller by a plug–in harness (two plugs).
