2
Series NRX with PXR - Instructions for
Spring Release, Latch Check Switch,
and Motor Operator
EATON
www.eaton.com
Instruction Leaflet
IL0131088EN
Effective May 2015
Section 1: General Information
Spring Release (SR)
A spring release is recommended for electrically operated circuit
breakers, although it is an optional device (Figure 1). It remotely
closes the circuit breaker when the coil is energized by a voltage input.
When a latch check switch is installed, the closing spring must be fully
charged and the trip latch reset (not held in the tripped position) for the
SR to operate. If these two conditions are not met, the close signal
will be ignored until it is removed and re-applied (Table 1).
Figure 1. Spring Release.
Latch Check Switch (LCS)
A latch check switch indicates when the circuit breaker is “ready to
close” (Figure 2 and Table 2). Two versions of the LCS are available:
1. Internal - The LCS wired to the spring release will not permit
activation of the spring release until the circuit breaker is fully
charged and the trip latch is reset. The LCS is supplied with two
leads and a small 2-pin connector.
2. External - The LCS used for remote indication consists of one
Form C contact wired to the circuit breaker secondary contacts for
integration into external control schemes.
Note:
Wiring the LCS for remote indication directly in series with the SR
accessory is not recommended as this will override the “anti-pump” feature.
The LCS is supplied with three leads and two secondary connectors.
Figure 2.
External LCS
Internal LCS
Latch Check Switches.
Table 1. Latch Check Ratings.
Control Voltage
Frequency
Contact Rating (Amperes)
250
50 - 60 Hz
10
125
DC
0.5
250
DC
0.25
Note:
Many illustrations use the NF Frame 1600A circuit breaker for illustrative
purposes only. The RF Frame 4000A circuit breaker is handled in a similar
fashion.
Table 2. Spring Release Ratings.
Control Voltage
Frequency
Operational Voltage (Range
85–110%)
Inrush Power Consumption
(VA)
Closing Time (ms)
24
DC
20 - 26
400
25
48
DC
41 - 53
500
25
60
DC
51 - 66
500
25
110 - 127
50 - 60 Hz
94 - 140
750
25
110 - 125
DC
94 - 138
750
25
208 - 240
50 - 60 Hz
177 - 264
800
25
220 - 250
DC
187 - 275
800
25