Eaton ATC-300 - Testing and Problem Solving; Testing Procedures

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Instructional Booklet
Page 30 Effective: March 2014
ATC-300 Breaker Based Transfer Switch
5.2 Manual Operation (225-1200 A)
The manual operating handle can be used to create the rotational
motion required to open and close the main contacts through a
rigid mechanical interlocking system (Figure 32). An indicator
wheel attached to the operating handle and mechanical interlock-
ing system rotates with each movement of the handle to open
and/or close the main contacts (Figures 33). Three distinct switch
positions are provided and indicated visually on the indicator
wheel (Figure 34).
Figure 32.ATS Manual Operating Handle in Use (225-1200 A
Models).
Figure 33.Indicator Wheel Mounted in the Switch with Motor
Under the Wheel (225-1200 A Models).
Figure 34.Indicator Wheel in Neutral Position (225-1200 A
Models).
The three distinct switch positions or contact conditions are:
Source 1: The contacts associated with the Source 1 power
source are closed and the Source 2 power source con-
tacts are open.
Neutral: The contacts associated with both the Source 1 and
Source 2 power sources are open. This position allows
for load circuit maintenance.
Source 2: The contacts associated with the Source 1 power
source are open and the Source 2 power source con-
tacts are closed.
To manually operate the ATS, the manual operating handle is
ratcheted until the desired switch position is indicated on the indi-
cator wheel. The operating handle, no matter what design or type
of switch operation, is always electrically "dead" and the indicator
wheel free-wheels should a particular switch have a motor and be
capable of electrical operation. This feature ensures no operator
problems should the switch automatically operate while the man-
ual handle is being used.
5.3 Manual Operation (30 - 150 A)
To operate the breaker manually, or if the breaker trips, unplug P3
from S3 to disconnect the motor circuit (Figure 35). Turn and
hold the break release lever to “HOLD FOR MANUAL OPERATION”
position, and then rotate the manual operator knob in either direc-
tion to move the ATS into the desired position. Let go of the
brake release lever for “AUTOMATIC OPERATION” after P3 and
S3 are reconnected.