E51SPL Eaton

INTRODUCTION
File E51 Sensors are comprised of 
three modular components, easily
 assembled to form a complete 
device. The components consist of 
a sensor head, a solid state plug-in 
switch and a wiring receptacle.
Any E51 Inductive Proximity, Photoelectric
 Fiber Optic Sensor Head 
may be used with the E51SNL or 
E51SPL switch bodies, allowing 
easy installation and modiffcation of 
switch function and sensing characteristics.
 The switch body plugs into the 
Eaton E51RN Wiring Receptacle, and 
connections to the line and loads are 
made according to the diagram below.
OPERATION
Customer connections to the sensor are made through the Catalog 
No. E51RN receptacle. Mechanical keying prevents other Eaton 
wiring receptacles from being used with the three-wire DC switch 
bodies. This will prevent the inadvertent installation of an AC switch 
body from being connected to a receptacle wired from a DC source, 
for example.
E51SNL and E51SPL Solid State Switches both have a normally 
open and normally closed (N.O. & N.C.) complementary output conffguration
 (refer to “Wiring Diagrams” below).
Both devices have factory-installed light emitting diodes which signify 
switch closure for both N.O. and N.C. contacts. These devices are 
also protected from damage should reverse polarity DC voltage be 
applied to them
The resettable short circuit protection feature built into these 
switches will turn the output off if the load is shorted or the output 
is inadvertently applied across the DC power supply. When the protection
 feature operates, it causes the light emitting diode for that 
output to turn OFF, as a fault indication. The output can be reset by 
cycling power, or by moving a target in and out of the sensing range.
When power is ffrst applied to the switch bodies, both N.O. and 
N.C. outputs will be open and both LEDs will be off. At the end of 
this “time before availability” period the outputs will be open or 
closed, as determined by the signal for the sensor head.
INSTALLATION
File E51 Switches may be wired into common conduit with wiring 
from other AC or DC control devices. Grounding by means of the 
grounding terminal provided in the wiring receptacle is optional or 
as required by the applicable electrical code.
Caution: E51SNL and E51SPL switches must always be connected 
with a suitable load. They should not be connected to 
relays whose pick-up currents exceed their maximum current 
rating. They should not be connected to incandescent 
lamp loads which exceed their incadescent steady state 
current rating. If the load current rating is exceeded, the 
short circuit protection feature may cause faulty operation.
Three-wire DC Devices - E51 three-wire DC sensors (both PNP and 
NPN) have two complementary outputs (1 N.O. - 1 N.C.). Two loads 
can be connected at the same time. To connect only one load, wire 
only the desired output terminal.
E51 three-wire devices have four terminals - two are connected directly 
across the line, the remaining two are for the two outputs to the 
loads. The operating current for the sensors (burden current) is supplied
 through the line connections - leakage current through the load 
in the microampere range is negligible.
Three-wire DC Sensors to Parallel - E51 three-wire DC sensors 
can operate in parallel to give an OR function.