9
Instruction Booklet
IB01900001E
Effective August 2017
Instructions for Magnum DS Metal-Enclosed
Low-Voltage ARC Resistant Switchgear Assemblies
EATON
www.eaton.com
3.4 Breaker Bellows
To provide an additional degree of protection to the operator in
event of an arcing event, arc resistant assemblies are equipped
with one breaker bellows in each cell containing a draw-out circuit
breaker (See Figure 6). The bellows is installed on the door and care
should be taken to prevent damage to the bellows when the door is
opened.
This breaker bellows provides a seal around the front of the breaker
that prevents dangerous arc gasses from escaping around the face
of the breaker in an arcing event. For this reason, it is important
that the bellows be in the correct position when the breaker door is
closed (See Figure 7). When closing the breaker door, ensure that all
four corners of the bellows pass around all four corners on the face
of the breaker. Figure 8 shows the bellows in the incorrect position.
When racking the breaker from disconnect position to the connect
position, the breaker bellows will move with the breaker.
WARNING
IT IS IMPORTANT TO PERIODICALLY INSPECT THE BREAKER BELLOWS FOR
DAMAGE. ANY HOLES, RIPS, TEARS, DEFORMATION, OR CRACKS INDICATE
THE BELLOWS (PART # 87C0111H01) SHOULD BE REPLACED.
DANGER
CLOSING THE BREAKER DOOR AFTER RACKING THE BREAKER TO THE
“CONNECT” POSITION WILL PREVENT THE BELLOWS FROM SEALING
PROPERLY. ALWAYS VERIFY THAT THE BREAKER IS IN THE “DISCONNECT”
POSITION WHEN CLOSING THE DOOR. ALWAYS VERIFY THE BELLOWS FITS
SECURELY AROUND THE BREAKER FACE WHEN CLOSING THE DOOR.
3.5 Bus Compartment
Exhaust openings exist in the top of the bus compartment. These
openings allow for dangerous gasses to escape the assembly during
an arcing event.
For arc resistant assemblies not equipped with the optional plenum,
(see Section 3.6), the exhaust openings in the top of the bus com-
partment are sealed with a pressure relief flap designed to open dur-
ing an arcing event. The flaps are held closed with plastic inserts that
will break loose and allow the flaps to open during an arcing event.
WARNING
WHEN THE PRESSURE RELIEF FLAPS ARE INSTALLED, IT IS CRUCIAL THAT
THE PLASTIC INSERTS ARE PRESENT TO HOLD ALL FLAPS DOWN. USE
OF ANY OTHER MEANS (I.E. BOLT AND WASHER) OR REMOVAL OF THE
PLASTIC INSERTS WILL VOID THE ARC RESISTANT RATING.
Figure 6. Beaker Bellows On Open Breaker Door.
Figure 7. Breaker Bellows On Closed Breaker Door.
Figure 8. Breaker Bellows In Incorrect Position.
