Eaton Series NRX Manual

Instructional Leaet IL01301014E Effective July 2016 Series NRX
Series NRX fixed circuit breaker arc
hood installation and removal
instructions
WARNING
(1) ONLY QUALIFIED ELECTRICAL PERSONNEL SHOULD BE PERMITTED TO
WORK ON THE EQUIPMENT.
(2) ALWAYS DE-ENERGIZE PRIMARY AND SECONDARY CIRCUITS IF A CIRCUIT
BREAKER CANNOT BE REMOVED TO A SAFE WORK LOCATION.
(3) DRAWOUT CIRCUIT BREAKERS SHOULD BE LEVERED (RACKED) OUT TO THE
DISCONNECT POSITION.
(4) ALL CIRCUIT BREAKERS SHOULD BE SWITCHED TO THE OFF POSITION AND
MECHANISM SPRINGS DISCHARGED. FAILURE TO FOLLOW THESE STEPS FOR
ALL PROCEDURES DESCRIBED IN THIS INSTRUCTION LEAFLET COULD RESULT
IN DEATH, BODILY INJURY, OR PROPERTY DAMAGE.
WARNING
THE INSTRUCTIONS CONTAINED IN THIS IL AND ON PRODUCT LABELS HAVE
TO BE FOLLOWED. OBSERVE THE FIVE SAFETY RULES:
– DISCONNECTING
– ENSURE THAT DEVICES CANNOT BE
ACCIDENTALLY RESTARTED
– VERIFY ISOLATION FROM THE SUPPLY
– EARTHING AND SHORT-CIRCUITING
– COVERING OR PROVIDING BARRIERS TO
ADJACENT LIVE PARTS
DISCONNECT THE EQUIPMENT FROM THE SUPPLY. USE ONLY AUTHORIZED
SPARE PARTS IN THE REPAIR OF THE EQUIPMENT. THE SPECIFIED
MAINTENANCE INTERVALS AS WELL AS THE INSTRUCTIONS FOR REPAIR AND
EXCHANGE MUST BE STRICTLY ADHERED TO PREVENT INJURY TO PERSONNEL
AND DAMAGE TO THE SWITCHBOARD.
Instructions apply to:
UL 1066/ANSI, UL489 series NRX NF frame
IEC IZMX16

2
Instructional Leaet IL01301014E
Effective July 2016
Series NRX xed circuit breaker arc
hood installation and removal
instructions
EATON www.eaton.com
ote:N The content of this IL applies to both PXR and Digitrip equipped break-
ers. Appearance of product may vary.
Section 1: General information
The arc hood on a Series NRX™fixed circuit breaker is positioned
over the breaker’s arc chambers. It is used primarily to direct arc
gas discharge (Figure 1). An arc hood is used on all fixed circuit
breakers, whether they are configured for front or rear connection
(Figure 1).
Mounted
arc hood
Figure 1. Fixed breaker arc hood.
Section 2: Arc hood installation
The arc hood pieces supplied fit together easily and accurately. To
assemble and install the arc hood, proceed with the following 12
steps:
Step 1: Remove the four screws holding the front cover in place
(two on each side of the cover).
Figure 2. Step 1.
Step 2: Remove the front cover. Pull down on the charging handle
to simplify removal.
Figure 3. Step 2.
Step 3: Remove the three mounting bolts holding the secondary
mounting bracket in place along with any mounted secondary blocks.
This will allow the secondary mounting bracket to be moved out of
the way permitting the first part of the arc hood to be installed.
Figure 4. Step 3.
1600 NRX SUB-TITLE IMAGE (12/15/2010)

3
Instructional Leaet IL01301014E
Effective July 2016
Series NRX xed circuit breaker arc
hood installation and removal
instructions
EATON www.eaton.com
Step 4: Become familiar with the top portion of the fixed breaker
where the arc hood will be mounted. T-shaped molded guides
located on top and between the arc chambers are key to the
installation. These T-shaped guides ensure accurate placement and
assembly of the arc hood pieces.
T-shaped
molded
guide
Figure 5. Step 4.
Step 5: Position part “A” as shown starting from the front of the
breaker so the two guides located on the bottom of part “A” mate
with the T-shaped guides on the breaker shown in Step 4. Slide
part “A” toward the rear of the breaker, ensuring that part “A” totally
engages the two guides on the breaker.
ote:N Part “A” is shown as being transparent only for clarity purposes.
Part “A”
Figure 6. Step 5.
Step 6: Remount the secondary mounting bracket removed in Step
3 using the three mounting screws. Hand tighten the mounting
screws.
Step 7: Once the secondary mounting bracket is securely mounted,
slide part “A” forward as far as it will go up against the back of the
secondary mounting bracket.
Step 8: Position part “B” as shown so the two guides located on
the bottom of part “B” mate with the same T-shaped guides on the
breaker shown in Step 4. Slide part “B” forward until it meets with
and is up against part “A.”
Part “B”
Figure 7. Step 8.
Step 9: Slide the three part “C” baffles (four for four-pole) all the
way into the slots provided in part “B” of Step 8 as shown. Make
certain that the baffle vent holes are oriented as shown.
Three part
“C” baffles
Figure 8. Step 9.
Step 10: Position the front of the arc chamber, part “D,” as shown in
front of part “B” so that the mounting holes in each part match to
accommodate two provided mounting screws.
Part “D”
Figure 9. Step 10.
Step 11: Hand tighten the supplied mounting screws as shown to
complete the arc hood installation.

4
Instructional Leaet IL01301014E
Effective July 2016
Series NRX xed circuit breaker arc
hood installation and removal
instructions
EATON www.eaton.com
Figure 10. Step 11.
Step 12: Replace the front cover, and secure it in place with the
mounting screws previously removed in Step 1.
Section 3: Arc hood removal
To disassemble and remove the arc hood from a fixed circuit breaker,
reverse the procedure just described in Section 2.

5
Instructional Leaet IL01301014E
Effective July 2016
Series NRX xed circuit breaker arc
hood installation and removal
instructions
EATON www.eaton.com
otes:N

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© 2016 Eaton
All Rights Reserved
Printed in USA
Publication No. IL01301014E / TBG001307
Part No. IL01301014EH03
July 2016
Eaton is a registered trademark.
All other trademarks are property
of their respective owners.
Series NRX xed circuit breaker arc
hood installation and removal
instructions
Instructional Leaet IL01301014E
Effective July 2016
Disclaimer of warranties and limitation of
liability
The information, recommendations, descriptions, and safety
notations in this document are based on Eaton’s experience and
judgment, and may not cover all contingencies. If further infor-
mation is required, an Eaton sales office should be consulted.
Sale of the product shown in this literature is subject to the
terms and conditions outlined in appropriate Eaton selling poli-
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WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE OR
MERCHANTABILITY, OTHER THAN THOSE SPECIFICALLY SET
OUT IN ANY EXISTING CONTRACT BETWEEN THE PARTIES.
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EATON. THE CONTENTS OF THIS DOCUMENT SHALL NOT
BECOME PART OF OR MODIFY ANY CONTRACT BETWEEN
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for any special, indirect, incidental, or consequential damage or
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use of equipment, plant or power system, cost of capital, loss
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resulting from the use of the information, recommendations, and
descriptions contained herein.
The information contained in this manual is subject to change
without notice.