Siemens Soft Starter Classification-2

1

3RW2122-1BG01

Housing: Flame-retardant polycarbonate (PC) with V0 fire rating; Internal contacts: Silver-nickel alloy (high conductivity & wear resistance); Insulation material: Epoxy resin (excellent electrical insulation)

1. Contact ablation due to long-term overload beyond rated current; 2. Component overheating caused by poor ventilation and dust accumulation; 3. Control circuit damage from grid voltage fluctuation (exceeding ±10%)

1. Monitor load current regularly to ensure it does not exceed the rated value; 2. Reserve ≥5cm ventilation space around the device and clean dust monthly; 3. Install a voltage stabilizer in areas with unstable power grids

1

3RW4056-2BB34, 3RW4056-2BB35, 3RW4056-2BB44, 3RW4056-2BB45, 3RW4056-6BB34, 3RW4056-6BB35, 3RW4056-6BB44, 3RW4056-6BB45

Housing: High-voltage resistant epoxy resin insulation; Internal thyristor: Porcelain-sealed high-voltage thyristor; Insulation oil: Transformer oil complying with GB 2536-2011 standard

1. Insulation breakdown caused by partial discharge; 2. Thyristor damage from grid overvoltage; 3. Insulation oil deterioration due to long-term use

1. Regularly test partial discharge (PD) value (≤50pC); 2. Install zinc oxide surge arresters at the high-voltage input end; 3. Replace insulation oil every 2 years and test dielectric strength (≥45kV/2.5mm)

2

3RW4073-2BB34, 3RW4073-2BB35, 3RW4073-2BB44, 3RW4073-2BB45, 3RW4073-6BB34, 3RW4073-6BB35, 3RW4073-6BB44, 3RW4073-6BB45

Housing: High-voltage resistant epoxy resin insulation; Internal thyristor: Porcelain-sealed high-voltage thyristor; Insulation oil: Transformer oil complying with GB 2536-2011 standard

1. Overheating of internal components due to poor heat dissipation; 2. Loose wiring terminals caused by mechanical vibration; 3. Control circuit failure from electromagnetic interference (EMI)

1. Ensure the cooling system operates normally and clean the radiator regularly; 2. Check terminal tightness monthly and use lock washers; 3. Use shielded cables for control wiring and ground the shield

3

3RW4074-2BB34, 3RW4074-2BB35, 3RW4074-2BB44, 3RW4074-2BB45, 3RW4074-6BB34, 3RW4074-6BB35, 3RW4074-6BB44, 3RW4074-6BB45

Housing: High-voltage resistant epoxy resin insulation; Internal thyristor: Porcelain-sealed high-voltage thyristor; Insulation oil: Transformer oil complying with GB 2536-2011 standard

1. Moisture intrusion leading to insulation degradation; 2. Thyristor aging caused by frequent startup; 3. Voltage surge damage during lightning strikes

1. Maintain ambient humidity between 45%-85% RH and install dehumidifiers if necessary; 2. Control startup frequency (≤3 times/hour for heavy loads); 3. Install lightning protectors at the power incoming line

4

3RW4075-2BB34, 3RW4075-2BB35, 3RW4075-2BB44, 3RW4075-2BB45, 3RW4075-6BB34, 3RW4075-6BB35, 3RW4075-6BB44, 3RW4075-6BB45

Housing: High-voltage resistant epoxy resin insulation; Internal thyristor: Porcelain-sealed high-voltage thyristor; Insulation oil: Transformer oil complying with GB 2536-2011 standard

1. Solder joint loosening of circuit board due to vibration; 2. Insulation oil leakage caused by seal aging; 3. Overload damage beyond thermal capacity

1. Inspect circuit board solder joints annually and re-solder if loose; 2. Replace sealing rings every 1.5 years; 3. Install current monitoring devices to alarm when overload occurs

5

3RW4076-2BB34, 3RW4076-2BB35, 3RW4076-2BB44, 3RW4076-2BB45, 3RW4076-6BB34, 3RW4076-6BB35, 3RW4076-6BB44, 3RW4076-6BB45

Housing: High-voltage resistant epoxy resin insulation; Internal thyristor: Porcelain-sealed high-voltage thyristor; Insulation oil: Transformer oil complying with GB 2536-2011 standard

1. Phase failure protection activation caused by three-phase voltage imbalance; 2. Display module damage from voltage fluctuation; 3. Component corrosion in corrosive environments

1. Regularly check three-phase voltage balance (imbalance rate ≤2%); 2. Install voltage limiters for the display circuit; 3. Use anti-corrosion enclosures in chemical or coastal environments

1

3RW4422-1BC34, 3RW4422-1BC35, 3RW4422-1BC36, 3RW4422-1BC44, 3RW4422-1BC45, 3RW4422-1BC46, 3RW4422-3BC34, 3RW4422-3BC35, 3RW4422-3BC36, 3RW4422-3BC44, 3RW4422-3BC45, 3RW4422-3BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Contact ablation from frequent heavy-load startup; 2. Overheating caused by blocked heat sinks; 3. Housing corrosion in high-humidity and dusty environments

1. Ensure a startup interval of ≥5 minutes for heavy loads; 2. Clean heat sinks monthly with compressed air; 3. Install dustproof and waterproof covers and inspect anti-corrosion coatings quarterly

2

3RW4423-1BC34, 3RW4423-1BC35, 3RW4423-1BC36, 3RW4423-1BC44, 3RW4423-1BC45, 3RW4423-1BC46, 3RW4423-3BC34, 3RW4423-3BC35, 3RW4423-3BC36, 3RW4423-3BC44, 3RW4423-3BC45, 3RW4423-3BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Phase failure damage from three-phase current imbalance; 2. Internal wiring loosening caused by vibration; 3. Control circuit damage from voltage fluctuation

1. Install three-phase current monitors (alarm when imbalance rate >3%); 2. Secure internal wiring with cable ties and inspect quarterly; 3. Install voltage stabilizers in unstable power grids

3

3RW4424-1BC34, 3RW4424-1BC35, 3RW4424-1BC36, 3RW4424-1BC44, 3RW4424-1BC45, 3RW4424-1BC46, 3RW4424-3BC34, 3RW4424-3BC35, 3RW4424-3BC36, 3RW4424-3BC44, 3RW4424-3BC45, 3RW4424-3BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Thyristor damage from harmonic interference; 2. Capacitor degradation leading to startup failure; 3. Overheating in closed, poorly ventilated environments

1. Install active harmonic filters in harmonic-prone power grids; 2. Test capacitor capacitance annually (replace if deviation >10%); 3. Equip closed cabinets with ventilation fans (airflow rate ≥0.5m/s)

4

3RW4425-1BC34, 3RW4425-1BC35, 3RW4425-1BC36, 3RW4425-1BC44, 3RW4425-1BC45, 3RW4425-1BC46, 3RW4425-3BC34, 3RW4425-3BC35, 3RW4425-3BC36, 3RW4425-3BC44, 3RW4425-3BC45, 3RW4425-3BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Arc-induced contact adhesion during startup; 2. Heat dissipation inefficiency from oil mist and dust on heat sinks; 3. Poor contact of communication interface

1. Install arc suppressors to reduce arc impact; 2. Clean heat sinks with degreasers in oil mist environments; 3. Inspect communication interfaces quarterly and clean pins with alcohol

5

3RW4426-1BC34, 3RW4426-1BC35, 3RW4426-1BC36, 3RW4426-1BC44, 3RW4426-1BC45, 3RW4426-1BC46, 3RW4426-3BC34, 3RW4426-3BC35, 3RW4426-3BC36, 3RW4426-3BC44, 3RW4426-3BC45, 3RW4426-3BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Power module damage from power surges; 2. Thermal protector failure from abnormal temperature rise; 3. Insulation material aging from high ambient temperature

1. Install surge protectors at the power input end; 2. Test thermal protector performance annually; 3. Avoid installation near heat sources and ensure good ventilation

6

3RW4427-1BC34, 3RW4427-1BC35, 3RW4427-1BC36, 3RW4427-1BC44, 3RW4427-1BC45, 3RW4427-1BC46, 3RW4427-3BC34, 3RW4427-3BC35, 3RW4427-3BC36, 3RW4427-3BC44, 3RW4427-3BC45, 3RW4427-3BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Moisture-induced internal short circuits; 2. Long-term overload exceeding thermal capacity; 3. Local overheating from loose terminals

1. Maintain ambient humidity ≤80% RH and install dehumidifiers if needed; 2. Limit overload time (≤15 minutes for 1.2x rated load); 3. Tighten terminals with a torque wrench (3-4N·m) and recheck quarterly

7

3RW4434-2BC34, 3RW4434-2BC35, 3RW4434-2BC36, 3RW4434-2BC44, 3RW4434-2BC45, 3RW4434-2BC46, 3RW4434-6BC34, 3RW4434-6BC35, 3RW4434-6BC36, 3RW4434-6BC44, 3RW4434-6BC45, 3RW4434-6BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Corrosion from corrosive gases in chemical environments; 2. Wiring errors leading to short circuits; 3. Secondary circuit poor contact leading to monitoring failures

1. Use anti-corrosion enclosures in chemical environments; 2. Verify wiring against diagrams and test insulation resistance (≥1MΩ) before power-on; 3. Tighten secondary circuit terminals and apply anti-oxidation paste

8

3RW4435-2BC34, 3RW4435-2BC35, 3RW4435-2BC36, 3RW4435-2BC44, 3RW4435-2BC45, 3RW4435-2BC46, 3RW4435-6BC34, 3RW4435-6BC35, 3RW4435-6BC36, 3RW4435-6BC44, 3RW4435-6BC45, 3RW4435-6BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Lightning-induced voltage surges damaging components; 2. Thyristor aging from long-term use; 3. Dust accumulation causing partial discharge

1. Install lightning protectors at the power incoming line; 2. Test thyristor on-state voltage drop annually and replace if exceeding standards; 3. Clean internal components every six months with compressed air

9

3RW4436-2BC34, 3RW4436-2BC35, 3RW4436-2BC36, 3RW4436-2BC44, 3RW4436-2BC45, 3RW4436-2BC46, 3RW4436-6BC34, 3RW4436-6BC35, 3RW4436-6BC36, 3RW4436-6BC44, 3RW4436-6BC45, 3RW4436-6BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Overheating from insufficient ventilation in high-temperature environments; 2. Vibration-induced internal component damage; 3. Display failure from electromagnetic interference

1. Install forced cooling systems in high-temperature areas; 2. Use shock-absorbing mounting brackets; 3. Ground the device reliably and use shielded cables for display wiring

10

3RW4443-2BC34, 3RW4443-2BC35, 3RW4443-2BC36, 3RW4443-2BC44, 3RW4443-2BC45, 3RW4443-2BC46, 3RW4443-6BC34, 3RW4443-6BC35, 3RW4443-6BC36, 3RW4443-6BC44, 3RW4443-6BC45, 3RW4443-6BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Contact wear from frequent startup/shutdown; 2. Circuit board damage from static electricity during maintenance; 3. Insulation degradation from oil pollution

1. Reduce unnecessary startup/shutdown operations; 2. Wear anti-static gloves and ground the equipment during maintenance; 3. Clean insulation components with alcohol regularly in oil-polluted environments

11

3RW4444-2BC34, 3RW4444-2BC35, 3RW4444-2BC36, 3RW4444-2BC44, 3RW4444-2BC45, 3RW4444-2BC46, 3RW4444-6BC34, 3RW4444-6BC35, 3RW4444-6BC36, 3RW4444-6BC44, 3RW4444-6BC45, 3RW4444-6BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Power module failure from voltage imbalance; 2. Seal aging leading to moisture intrusion; 3. Overload damage from incorrect parameter settings

1. Monitor three-phase voltage in real time; 2. Inspect seals quarterly and replace if damaged; 3. Set parameters strictly according to the motor nameplate and operation manual

12

3RW4445-2BC34, 3RW4445-2BC35, 3RW4445-2BC36, 3RW4445-2BC44, 3RW4445-2BC45, 3RW4445-2BC46, 3RW4445-6BC34, 3RW4445-6BC35, 3RW4445-6BC36, 3RW4445-6BC44, 3RW4445-6BC45, 3RW4445-6BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Thermal overload damage from long-term heavy-load operation; 2. Wiring terminal overheating from poor contact; 3. Component aging from long service life

1. Arrange regular shutdown maintenance for heavy-load equipment; 2. Check terminal temperatures with an infrared thermometer monthly; 3. Replace key components (thyristors, capacitors) every 5 years

13

3RW4446-2BC34, 3RW4446-2BC35, 3RW4446-2BC36, 3RW4446-2BC44, 3RW4446-2BC45, 3RW4446-2BC46, 3RW4446-6BC34, 3RW4446-6BC35, 3RW4446-6BC36, 3RW4446-6BC44, 3RW4446-6BC45, 3RW4446-6BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Electromagnetic interference causing control failure; 2. Heat sink blockage from dust accumulation; 3. Thyristor breakdown from voltage spikes

1. Use shielded control cables and keep them away from high-voltage cables; 2. Clean heat sinks monthly in dusty environments; 3. Install spike suppressors at the power input end

153

3RW4447-2BC34, 3RW4447-2BC35, 3RW4447-2BC36, 3RW4447-2BC44, 3RW4447-2BC45, 3RW4447-2BC46, 3RW4447-6BC34, 3RW4447-6BC35, 3RW4447-6BC36, 3RW4447-6BC44, 3RW4447-6BC45, 3RW4447-6BC46

Housing: Die-cast aluminum alloy with anti-corrosion coating; Power contacts: Silver-tungsten alloy (high temperature & arc resistance); Heat sink: Ribbed aluminum alloy (efficient heat dissipation)

1. Moisture corrosion in high-humidity environments; 2. Overheating from incorrect cooling system settings; 3. Communication failure from poor interface contact

1. Install dehumidifiers in high-humidity workshops; 2. Check cooling system parameters regularly to ensure normal operation; 3. Clean communication interfaces with a soft brush quarterly

How to correctly select the 3RW series soft starter model for my equipment?

First, confirm the motor's rated power, rated voltage, and load type (light/medium/heavy). For small motors (≤15kW) with light loads, choose the 3RW21 series; for medium-voltage motors (6kV-10kV), choose the 3RW40 series; for high-power heavy-load motors (≥55kW), choose the 3RW44 series. Ensure the soft starter's rated current is 1.1-1.2 times the motor's rated current. For complex scenarios, refer to Siemens' official selection guide or consult technical support.

What are the key items for routine maintenance of Siemens 3RW series soft starters?

Key maintenance items: 1. Check wiring terminals for tightness and overheating signs (discoloration); 2. Clean heat sinks, fans, and dust covers to ensure heat dissipation; 3. Test three-phase voltage/current balance (imbalance rate ≤2%); 4. Verify parameter settings and back up data; 5. Inspect seals and insulation layers for aging/damage; 6. Test protection functions (overload, phase failure) to ensure normal operation.

What should I do if the soft starter reports an overload fault frequently?

First, check if the actual load exceeds the motor's rated load. If the load is normal, check if the soft starter's overload protection parameter is set correctly (should match the motor's thermal characteristic). Also, check the heat dissipation system for blockage and the three-phase current balance. If the fault persists, inspect the power module and thermal protector for damage, and replace them if necessary.