Cut Sheet

V7-T3-188 Volume 7—Logic Control, Operator Interface and Connectivity Solutions CA08100008E—July 2015 www.eaton.com
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3.9
Control Relays and Timers
Alternating Relays
D85 Series—Alternating Relays
Contents
Description Page
D85 Series—Alternating Relays
Product Selection . . . . . . . . . . . . . . . . . . . . . . . V7-T3-189
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . V7-T3-189
Technical Data and Specifications . . . . . . . . . . V7-T3-190
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . V7-T3-190
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . V7-T3-192
Product Description
Alternating relays are used
in applications where the
optimization of load usage is
required by equalizing the run
time of two loads. They are
also used where additional
capacity is required in case
of excess load requirements.
This alternating action is
initiated by a control switch—
such as a float switch, manual
switch, timing relay, pressure
switch or other isolated
contact. Each time the
initiating switch is opened,
the output relay contacts will
change state, thus alternating
the two loads. Two LED
indicators show the status of
the output relay.
The D851 and D852 Series
Relays are used with one
control switch and are
available in either SPDT or
DPDT output configurations
with or without a selector
switch to lock in one
sequence. The D852X Series
Relays are available in DPDT
cross-wired output
configurations for use with
one or two control switches
(LEAD and LAG).
The D853 Series is designed
for use with three-switch
applications (LEAD, LAG and
STOP). The D853 Series
combines a standard DPDT
Cross-Wired alternating relay,
contactor auxiliary contacts,
and a control relay into one
compact and economical
product. This saves space
and labor, while reducing the
number of components
needed. The D853 Series
uses Sequence On–
Simultaneous Off (S.O.S.O.)
operation, where the two
loads are energized
sequentially, but remain on
together until the STOP
switch is opened. This device
also protects against failure of
the STOP and LEAD
switches. If both switches
fail, the two pump motors will
be energized simultaneously
when the LAG switch is
closed.
Each of the D85 Series
alternating relays is available
with an optional three-
position selector switch,
which allows the unit to
alternate the two loads as
normal, or lock the relay to
one load or the other. By
locking the alternating relay to
one load, the other load can
be removed for service
without rewiring the first load
for continuous operation. The
selector switch has a low
profile to prevent any
accidental actuation.
Features
●
For duplex loads
●
Works with one-, two-, or
three-switch applications
●
Compact plug-in design
using industry standard
sockets
●
10 A SPDT or DPDT output
configurations
●
Optional low profile
selector switch to lock in
one sequence
●
Two LEDs indicate relay
status
●
D853 Series replaces
separate components in
duplex panel—saving
space and reducing labor
Standards and
Certifications
●
CE
●
cRUus
●
UL listed
1
●
RoHS compliant
Note
1
When used with appropriate Eaton
socket.