SEW BW033-012 Detailed Product Description

SEW BW033-012 is a small-power brake resistor of the SEW BW series, specially designed for 2.2–5.5kW servo/frequency conversion systems, used for quickly discharging the regenerated electrical energy of the motor, stabilizing the DC bus voltage, and protecting the power devices of the driver. It is suitable for small inertia, frequent braking, and light-load energy load operation conditions.

I. Basic Information

Product Series: BW Series Brake Resistor (Brake Resistor)

Full Model: BW033-012

Variant Model: BW033-012-T (Metal Mesh Cover, IP54 Protection)

Product Type: Wound-Resistor, Aluminum Shell Wave-Resistor, With Temperature Control Protection

Manufacturer: SEW-EURODRIVE (Germany)

Compatible Equipment: SEW MOVIDRIVE, BTS20, MOVITRAC, MDX61/60 Series Drives

Application Scenarios: Rapid Braking, Frequent Start/Stop, Light Load Lifting, Small Inertia Equipment

Protection Grade: IP20 (Standard) / IP54 (-T Type)

Cooling Method: Natural Cooling (Optional Forced Air Cooling)

II. Model Meaning Interpretation

BW: Brake Resistor (Brake Resistor) Series

033: Nominal Resistance Value 33Ω (Ohm)

012: Rated Power 1.2kW (1200W)

III. Core Technical Parameters

1. Electrical Parameters

Rated Power (PR): 1.2kW (Continuous, 100% ED)

Peak Power (PP): 12kW (Short Time, 10s, 10% ED)

Nominal Resistance (R): 33Ω ±5%

Voltage Rating: 800V DC (Compatible with 300–600V DC Bus)

Insulation Class: F Grade (155℃)

Temperature Switch: Built-in Normally Closed 85℃ Temperature Control, Overheating Cut-off, Linked Driver Alarm

Maximum Temperature Rise: 375℃ (Resistance Wire)

Shell Temperature: ≤120℃ (Safe Contact)

2. Physical Parameters

Package: Aluminum Shell Wave-Resistor (BW033-012) / Metal Mesh Cover (BW033-012-T)

Size (W×H×D): Approximately 250×180×120mm

Weight: Approximately 3.8kg

Installation Method: Wall-mounted, Vertical Installation

Terminal: 2×M6 Screw Terminals

3. Environmental Characteristics

Operating Temperature: -25℃ ~ +45℃

Humidity: 5–95% (No Condensation)

Vibration Resistance: Industrial Grade, Compatible with Machines, Conveyor Equipment

Life: 10,000 Hours (Full Load)

IV. Functions and Advantages

1. Precise Small Power Braking

1.2kW/33Ω: Compatible with 2.2–5.5kW servo/frequency conversion systems

Peak 12kW: Satisfies small inertia, frequent braking, light-load lowering

Low Inductance Design: Does Not Interfere with Servo Control, Precise Positioning

2. Safe and Reliable

Dual Protection: 85℃ Temperature Switch + High Insulation Voltage Rating

Industrial Grade Material: High-temperature Resistance Wire, Corrosion-Resistant Shell

Long Life: Solid State Resistance, No Aging, No Maintenance Required

3. Strong Compatibility

SEW Original: Directly Match MOVIDRIVE, BTS20, MDX60 Series

Voltage Compatibility: 300V/600V DC Bus Common

Installation Flexible: Vertical Installation, Forced Air Cooling Optimization, Multiple Units Parallel Expansion

4. Maintenance Convenient

Status Monitoring: Temperature Switch Connected to Driver BRK Terminal

Replacement Convenient: Standard Size, Direct Replacement with Same Specification Resistors

No Maintenance Required: No Consumables, Long-Term Stable Operation

V. Typical Applications

Compatible Power: 2.2–5.5kW Frequency Converters / Servo Drives System Configuration: Drive + BW033-012 + Servo / Variable Frequency Motor

Typical Operating Conditions:

Braking of small machine tool spindles and servo axes

Light-load lifting platforms, parking garages, conveyors

Emergency stop of small fans, pump-type small inertia equipment

Frequent start-stop and forward/reverse operation of packaging, printing, and textile equipment

VI. Selection and Installation Tips

Power Matching: Braking power ≤ 1.2kW (continuous)

Resistance Matching: Recommended for drive braking unit 33Ω

Voltage Matching: DC bus ≤ 600V DC

Heat Dissipation: Vertical installation, spacing ≥ 50mm, forced air cooling is better

Wiring: Short, thick, straight wiring (≥ 4mm² cable), reduce voltage drop and interference

Protection: Temperature control switch connected to driver BRK terminal to achieve overheat protection

VII. Order Information

Model: BW033-012 (aluminum case, IP20)

Variant: BW033-012-T (net cover, IP54)

Order Number: 17962196

Guarantee: 12 months

Standard Equipment: Resistor body, installation screws, temperature control switch wire

VIII. Comparison with the Same Series

BW012-050: 1.2kW / 50Ω (suitable for 2.2–5.5kW)

BW033-012: 1.2kW / 33Ω (current) (suitable for 2.2–5.5kW)

BW027-006: 600W / 27Ω (lower power)

BW018-035: 3.5kW / 18Ω (higher power)