Emerson 7ACTB Switch User Manual


 
INSTALLATION (continued)
1 --- 2
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 ACTB until
they are tested. Installing power cables i n 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 t he cables are pulled into position,
and before they a re 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 l ife of the ACTB switch.
Connecting Power Conductors
A Wiring Diagram isfurnished withthe ACTB. Allwiring
must be made in accordance with the local codes. After
the power cables have been tested, connect them to the
appropria te terminal lugs on t he Bypass Switch as shown
on the wiring diagram provided with this ACTB. Make
sure that the lugs provided are suitable for use with the
cables being installed. Standard terminal lugs are
solderless screw type and will accept the wire sizes listed
on the drawings provided with the ACTB. Be careful
when stripping insulation from conductors; avoid nicking
or ringing the conductor. Remove surface oxides from
conductors by cleaning with a wire brush. Follow
conductor manufacturer’s instructions when aluminum
conductor is used. Apply joint compound to conductor,
then carefully wipe away excess compound. Tighten the
cable lugs to the torque specified on the rating label.
Be sure that the Normal and Emergency power
connections are in proper phase rotation.
Bus Connections
If bus connection i s used, use SAE grade 5 hardware to
connect bus to appropriate terminal plates on bypass
switching device. Wipe off bus surfaces before they are
joined. If bus is dirty, gently clean surfaces with a
non-flammablesolvent. Avoidtouching cleaned surfaces.
Do not breathe cleaning solvent vapors.
UseSAEgrade5hardwareandtightentheboltedjoints
tothetorquespecifiedinTable2-1.
The reliability of the connection depends
on how clean and how tight the joint is.
Table 2-1. Tightening torque values for bolted joints.
Bolt Diameter
(Grade 5 hardware)
in inches
Recommended
Tightening Torque
in foot pounds
5/16 12
3/8 20
1/2 50
5/8 95
Harnesses
All internal connections are made at the factory. The
bypass switch, transfer switch, and control panel are
joined together by an interconnecting wire harness. The
disconnect plugs are already engaged on enclosed
switches. For open–type switches, the plugs must be
engaged after installation is completed. Align harness
plugs with sockets i n the control and push them together
until they are secure.
Controller Ground
A grounding wire must be connected to the controller’s
lower left mounting st ud. 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.
Engine Starting Contacts
and Auxiliary Circuits
The engine control contact signal connections and
auxiliary circuits are located on terminal block TB as
shownontheWiring Diagram provided with the ACTB.
Connect the signal wires to the appropriate terminals.