Eaton NRX Instruction Manual

Also see for NRX: Installation instructions

14Section 3: General operation and circuit breaker descriptionSeries NRX with PXR - type RF low voltage power (air) circuit breakers instruction manual MN013002ENH03 September 2016 www.eaton.comStep 3: Carefully push the circuit breaker into its compart-ment until it stops. The extension rails can now be foldedup and latchedFigure 21. Step 3.Step 4: The breaker is ready to be levered. With the circuitbreaker OPEN, reset the detent system by sliding the greybutton to the right, then release (Figure 20a). Rotate thelevering tool clockwise to the different available positions(DISCONNECT, TEST, CONNECT).ote:N The position indicator on the lower right portion ofthe breaker indicates the position as each positionis reached. The levering detent system will alsoengage, stopping breaker travel.When the breaker reaches the CONNECT position, ahard stop is encountered. Discontinue levering to avoiddamage due to torquing beyond the maximum of15 ft-lbs (20.3 N•m).Figure 22. Step 4.Note: Full connect = hard stopStep 5: To remove the circuit breaker from any position orfrom the compartment completely, reverse the insertionprocedure just described in Steps 1 through 4 by rotatingthe levering tool in a counterclockwise direction. When theDISCONNECT position is reached, the circuit breaker will nolonger move out of the cassette as a result of rotating thelevering tool. At this point, the circuit breaker can be pulledout of the cassette onto its drawout rails.IMPORTANTThe circuit breaker mechanism is interlocked such thatcharged closing springs are automatically discharged if thecircuit breaker is levered into or out of the cell. Dischargetakes place between the DISCONNECT and TEST positions.Installing fixed circuit breakerA fixed circuit breaker is solidly mounted in its structurewith no drawout feature. The circuit breaker is available inrear-connected configurations (Figure 23) and can be mount-ed on a suitable horizontal mounting surface using left- andright- side mounting feet. Refer to Section 6 for breaker andprimary bus stab details and requirements.Figure 23. Fixed breaker.Basic circuit breaker assemblySeries NRX circuit breakers use a rigid frame compositehousing construction. This construction provides high-strength structural properties, excellent dielectric charac-teristics, and arc tracking resistance. They are availablewith various connection configurations and specific ratingsdictated by the applicable standards (see www.eaton.com/seriesnrx.)Each pole has one primary contact assembly comprised ofa moving portion and a fixed portion. The exact design con-figuration depends upon the breaker’s frame size and inter-ruption rating.!