BR/SUxxxUC Series
UL 489 and UL 1077 – AC/DC Rated
Miniature Circuit Breakers
BR and SU Series|
Thermal Magnetic Miniature Circuit Breakers
Application Schematic
G
L1
L2
L3
Power Circuit
UL489
BR2xxUC
UL489
BR3xxUC
Power Circuit
Control Circuit
Control Transformer
UL489
BR2xxUC
UL1077
SU1xxUC
Power
Transformer
UL489
BR1xxUC
UL489
BR1xxUC
UL489
BR2xxUC
Power
Transformer
UL1077
SU2xxUC
UL489
BR3xxUC
UL1077
SU1xxUC
UL489
BR1xxUC
M
Outlet
Fixed mounted
cabinet /panel heater
(resistive loads)
M
Sizing of main branch circuit protector according
to table 430.52 in NEC
®
•
Dual Element (Time Delay) Fuse
Maximum fuse
= largest motor FLA x 175%
+ FLA of all other motors and general loads in group
•
Inverse Time Breaker
Maximum circuit breaker = largest motor FLA x 250%
+ FLA of all other motors and general loads in group
(for other fuse/breaker types see table 430.52)
BR and SU Series|
Thermal Magnetic Miniature Circuit Breakers
UL 489 and UL 1077 DIN-Rail Miniature Circuit Breakers
Weidmuller offers a complete line of thermal magnetic circuit breakers with its BRxxxUC product line engineered for either
AC or DC branch circuit protection and the SUxxxUC product line designed for supplementary protection. These circuit
breakers are proven solutions to protect your wires and cables from application or device malfunctions.
Introduction
......................................................................................................................................................... 2
Choose the Right Weidmuller BR/SUxxxUC Series Miniature Circuit Breaker ...................... 2
Applications ............................................................................................................................................ 3
BR and SU Series Product Overview
........................................................................................................ 4
UL 489 DIN-Rail Branch Circuit Breakers
............................................................................................... 5
BRxxxUC Product Selection ............................................................................................................... 6
UL 1077 DIN-Rail Supplementary Circuit Breakers
........................................................................... 7
SUxxxUC Product Selection . .............................................................................................................. 8
Trip Curves
........................................................................................................................................................... 9
Accessories
....................................................................................................................................................... 11
Accessory Modules ........................................................................................................................... 11
Auxiliary Contact ......................................................................................................................... 11
Bell Alarm Contact ...................................................................................................................... 12
Shunt Trip ...................................................................................................................................... 13
Accessory Modules Installation Diagram .................................................................................... 14
Accessory Modules Mounting Instructions ................................................................................ 15
Busbar and Busbar Accessories ...................................................................................................... 16
Busbar UL 489 – Cuttable ........................................................................................................ 16
Busbar UL 1077 – Cuttable ...................................................................................................... 18
Terms
................................................................................................................................................................... 20
Additional Technical Information
........................................................................................................... 21
Operation and Components of BR/SUxxxUC MCBs ................................................................. 21
Weidmuller UC Series Thermal Magnetic Definition
................................................................ 22
Examples of Trip Curve Interpretation – Reading Trip Curves ................................................ 23
Ambient Temperature Derating ...................................................................................................... 24
UC Series D Curve Thermal Magnetic Tripping Characteristics vs K Curve ........................ 25
Additional Weidmuller Offerings
........................................................................................................... 27
CB4200 Series Circuit Breakers ..................................................................................................... 27
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BR and SU Series|
Thermal Magnetic Miniature Circuit Breakers
Introduction
Choose the Right Weidmuller BR/SUxxxUC
Series Miniature Current Breaker (MCB)
(Always refer to the NEC before installing any device.)
When considering the BR/SUxxxUC Series MCBs, always assess the application for the following: voltage rating,
maximum interrupting capacity, continuous current rating, frequency, and atypical operating conditions (ambient
temperature, moisture, vibration, altitude, installation or operation orientation, and field maintenance). The MCBs are
intended to protect the circuit cables as well as motors, generators and transformers, thyristors and silicon rectifiers.
They also provide additional protection of computers and their peripheral equipment, industrial process control systems,
telecommunications equipment and power supplies.
Ask the following:
• Is the application an AC or DC circuit?
Good news here, BR/SUxxxUC MCBs are rated for both AC
and DC.
• Is a branch or supplemental breaker needed for the
application?
Branch devices may be used in place of supplemental but
not vise versa.
• How many poles are needed for each circuit being protected?
3p – 3 phase no neutral, 2p – L
1
and Neutral, 1p – L
1
only.
• Calculate and/or measure the normal current for the circuit
and follow NEC guidelines. Match the breaker amps based on
the normal current load. Weidmuller’s BR/SUxxxUC run 1 to
63 amps (See Technical Data on page 4).
• Determine potential failure mode(s).
BR/SUxxxUC MCB thermal magnetic devices are designed for
interrupt short-circuit and overload events.
• What is the interrupt capacity (IC)?
Specify the breaker knowing the maximum fault current that
can be repeatedly interrupted without failure of the breaker.
BR/SUxxxUC MCBs have a maximum current at a given
voltage that the breaker can interrupt safely without damage
to surrounding components. (See Technical Data)
• What is the reaction time needed to a given fault condition?
Specify a breaker by selecting a speed that avoids nuisance
tripping but protects against component damage (B, C or
D curve)
• What are the functional requirements of the breaker?
The BR/SUxxxUC are rail mountable, easy to visually inspect,
switch manually (or remotely trip with shunt trip devices)
and monitor using an auxiliary contact. Mechanically 20,000
cycles and electrically 6,000 cycles.
• What is the wire size used? Can the breaker accept the wire
sizes required?
The BR/SUxxxUC are designed for ≤35mm².
• What are the environmental factors: ambient temperature,
moisture, vibration?
Check to determine if there are unusual conditions in which
the breaker must operate. The BR/SUxxxUC are specified to
IP20, -35°C ...70°C, and shock tested to IEC 60068-2-27.
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BR and SU Series|
Thermal Magnetic Miniature Circuit Breakers
Applications
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Automotive Manufacturing
Chemical, Oil and Gas
Renewable Energy
Rail Vehicles
Automation
Pharmaceutical and Food
Steel Production
Telecom and Datacom
Power-D-Box-Systems
Lighting Equipment
Process Control
Pharmaceutical and Food
Chemical, Oil and Gas
Automotive Manufacturing
Rail Vehicles
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