Siemens · Soft Starters
Siemens SIRIUS 5L3 repair
Send the Siemens SIRIUS 5L3 for diagnosis and repair, or have an engineer come to the plant. Repair keeps the original soft starter, its settings and its wiring in place.
Cost confirmed before any work starts · Warranty of 30 days to 6 months
At a glance
The Siemens SIRIUS 5L3
- Manufacturer
- Siemens
- Model / part number
- SIRIUS 5L3
- Also searched as
- SIRIUS5L3
- Description
- SOFT starter 3RW4073-6BB44
- Category
- Soft Starters
- Service
- Diagnosis and component-level repair, onsite or ship-in
- Warranty
- 30 days to 6 months, confirmed before work starts
Siemens automation and drives equipment, including SIMATIC PLCs and HMIs, SINAMICS and MICROMASTER drives, SIMOREG DC drives and SINUMERIK CNC controls, is found across Indian manufacturing and process plants, often running alongside older generations of the same family.
Common faults
What usually fails on a unit like the SIRIUS 5L3
Soft starters are simpler than drives, but they work hard: every start pushes high current through the thyristors. Most faults are in the power section, the bypass contactor or the control card.
Shorted thyristors
A shorted thyristor makes the motor start direct-on-line or trips the starter on a phase fault.
Bypass contactor or relay wear
Worn bypass contacts overheat once the motor is up to speed, causing thermal trips after the start.
Overheating from frequent starts
Starts per hour above the rating, or blocked cooling, cause thermal trips and long-term thyristor damage.
Control card faults
A dead display, no start command response or wrong current readings point to the control electronics.
Phase loss and imbalance trips
Often the supply or motor, but sometimes the starter's own current sensing.
First checks
What to check before calling an engineer
Isolate and lock out the supply, and wait for stored energy to discharge, before opening anything.
Safe for plant staff
- Note the trip message and whether it happens during or after the start.
- Measure supply voltage on all phases.
- Count starts per hour against the starter's rating.
Leave to a specialist
- Testing thyristors and the bypass circuit.
- Adjusting current limit and ramp settings for a heavy load.
- Any work inside the starter with the supply connected.
Getting it fixed
How to get the SIRIUS 5L3 repaired
What to send with it
- The soft starter with its control card fitted.
- The trip message and the motor rating.
- What it starts (pump, compressor, crusher, fan) and how often.
Onsite or ship-in
Technicians work onsite from our Hyderabad base and travel to plants across India; anything that can be removed can also be sent to MachineryFix from anywhere in the country.
Warranty. Repairs carry a warranty of 30 days to 6 months, depending on the item and the repair; the exact term is confirmed before work starts.
FAQ
SIRIUS 5L3 repair questions
Why does the Siemens SIRIUS 5L3 trip only after the motor reaches speed?+
That usually points to the bypass contactor or its control, or to heat building up in the starter. Both are checked during the repair.
Does the Siemens SIRIUS 5L3 have to be sent in, or can an engineer come to the plant?+
Either. An engineer can diagnose it in place and repair it there or take it away, or the unit can be sent to MachineryFix from anywhere in India. The diagnosis and repair cost are confirmed before any work starts.
Is MachineryFix connected to Siemens?+
No. Siemens and the model name are used only to identify the equipment. MachineryFix is an independent repair service and is not affiliated with or endorsed by Siemens.
Same manufacturer
Other Siemens Soft Starters
Other manufacturers
Soft Starters from other makers
Siemens and SIRIUS 5L3 are named only to identify the equipment. MachineryFix is not affiliated with or endorsed by Siemens.
SIRIUS 5L3 down?
Send the fault and what the machine was doing. We'll match an engineer who works on it.