Brochure

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General,
description
0
Solid-State Overload Relays 0
Motor Logic
®
base unit
Motor Logic
®
feature unit
Motor Logic
®
Plus programmable unit
General
Overload relays are intended to protect motors, controllers and branch-circuit conductors against excessive
heating due to prolonged motor overcurrents up to and including locked rotor currents. Protection of the motor and
the other branch-circuit components from higher currents, due to short-circuits or earth faults, is a function of the
branch-circuit fuses, circuit-breakers or motor short-circuit protectors.
Electric motors make up a large percentage of power system loads. Market demands for reduced downtime and
increased productivity have compelled the motor control industry to continuously evaluate motor protection technology.
Technology advancements now allow the motor control industry to offer several options for motor protection.
This briefly reviews traditional motor protection technologies and discusses the new, electronic motor protection
options. Important factors to consider in determining the appropriate overload protection include:
b Application requirements.
b Cost per feature of a given technology.
b Willingness and ability of all parts of the user's organization to embrace and implement the new technology.
Motor failure may be the result of electrical or mechanical factors. A study commissioned by the Electrical
Research Associates (ERA) of the United Kingdom indicated that the most common causes of motor failure are:
1 Overcurrent
2 Contamination
3 Single phasing
4 Bearing failure
5 Aging (natural wear)
6 Rotor fault
7 Miscellaneous
30 %
18 %
15 %
12 %
10 %
5 %
7 %
Failure modes 1, 3 and 7 are attributable to electrical issues. Modes 2, 4, 5 and 6 are the result of mechanical (and
some manufacturing) issues.
Historically, motor protection provided with the controller was only able to address the electrical causes of motor
failure. These electrical issues account for at least 45% of the most common causes of motor failure. Motor branch
circuits are protected against short circuits (instantaneous overload currents) and steady-state or low-level
sustained overloads. In the U.S., this protection is provided by the short-circuit protective device (SCPD) and the
motor overload relay, when they are applied according to the National Electrical Code (NEC).
Motor Logic solid-state overload relay base unit
As the market leader in motor control products, Square D offers the Motor Logic solid-state overload relay base
unit. It provides the most complete electronic overload protection available to date for the price.
Motor Logic solid-state overload relay feature unit
The Motor Logic solid-state overload relay feature unit offers the same features as the base unit, along with the
following:
b Class II earth fault detection to protect motors from hard-to-find earth fault conditions.
b Switch-selectable trip class (Class 10 or Class 20) for application flexibility in a single unit.
Motor Logic Plus programmable solid-state overload relay
The Motor Logic Plus programmable solid-state overload relay is a fully programmable overload relay designed to
monitor three-phase a.c. motor systems. It has 16 programming parameters of which eight can be viewed from
the 3-digit alphanumeric LED display screen on the face of the overload relay. Additionally, these parameters can
be viewed through the use of a personal computer for remote access to motor performance and adjustments.
Description
Motor Logic solid-state overload relays 9065 Sp include:
1 Adjustment dial
2 Tamper-proof cover
3 Reset button
Motor Logic Plus programmable solid-state overload relays 9065 SP include:
1 Mode select switch (1)
2 3-digit alphanumeric LED display screen
3 Display/Program switch
4 Communication port (on side)
5 Reset/Program button
(1) Low voltage set point, High voltage set point, Voltage unbalance set point, Overcurrent trip point, Undercurrent trip point,
Current unbalance trip point, Trip class (5, 10, 15, 20, 30), Rapid cycle timer (RD1), Overload restart delay (RD2), Underload
restart delay (RD3), Number of restarts after an overload, Unbalance, Single phasing (manual or automatic), RS-485 address,
Number of restarts after an underload fault, Underload trip delay and Earth fault trip point, Individual line voltages, Current
levels, as well as Average voltage and Average current.
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Characteristics:
page 3/3
References:
pages 3/6 and 3/7
Dimensions:
page 3/8