siemens
Siemens SINAMICS SL150 Medium-Voltage Softstarter
Model: SL150
4-hour response · Pricing in SAR · Delivery across all KSA regions
SL150 — Siemens SINAMICS SL150 Medium-Voltage Softstarter
The Siemens SINAMICS SL150 is a thyristor-based solid-state medium-voltage softstarter covering 2.3 kV to 13.8 kV and motor power up to 10 MW, providing controlled voltage ramp starting and current-limit starting for large MV induction motors where the full investment in a MV variable speed drive is not justified for fixed-speed or limited variable-speed applications. The SL150 limits motor starting current to a selectable percentage of locked-rotor current (typically 300–400% FLC versus 600–700% FLC for direct-on-line starting), reducing the voltage dip on the MV bus during start-up and limiting mechanical torque shock to the driven equipment — the two primary reasons that direct-on-line starting of large MV motors is prohibited at many Saudi industrial facilities with limited utility supply capacity.
The SL150's electromechanical bypass contactor closes automatically at the end of the starting ramp, connecting the motor directly to the supply for the running condition — completely bypassing the thyristors and maintaining running efficiency equal to direct-on-line operation with zero thyristor losses during the running period. The integrated digital control system provides adjustable starting voltage, current limit setpoint, ramp time (5–120 seconds), and deceleration ramp for controlled soft stop, configurable via a front-panel keypad or Modbus/PROFIBUS communication interface. Motor thermistor inputs and motor protection functions are built in, eliminating the need for a separate motor protection relay in many applications.
In Saudi Arabia, the SINAMICS SL150 KSA is the preferred starting method for large MV pump and fan motors (typically 500 kW to 5 MW) at water utility pumping stations operated by NWC and SWCC, industrial cooling water pump motors at SABIC and Aramco facilities, and large induced draught fan motors at cement kilns and power plant boilers — where the infrequent starting duty (2–6 starts per day) makes the economics of a full MV VFD difficult to justify but the supply authority prohibits direct-on-line starting above certain kVA limits. SEC's technical requirements restrict DOL starting current impact on the supply for motors above 500 kW in many grid configurations.
Razz Middle East supplies SINAMICS SL150 systems with full project engineering, MV switchgear interface, protection co-ordination, and commissioning in Saudi Arabia.
Technical Specifications
Full specifications for the SL150
- Voltage Range
- 2.3–13.8 kV
- Motor Power
- Up to 10 MW
- Starting
- Voltage ramp + current limit
- Bypass
- Electromechanical contactor (automatic)
- Ramp Time
- 5–120 s adjustable
- Deceleration
- Soft stop ramp option
- Communication
- Modbus, PROFIBUS
- Cooling
- Air or water cooled
- Protection
- Motor thermistor, overcurrent, phase loss
- Compliance
- IEC 60947-4-2, Aramco specifications
Key Features & Benefits
- Current-limit starting restricts motor starting current to 300–400% FLC versus 600–700% for DOL, limiting MV bus voltage dip to below 5% at the point of common coupling — meeting SEC's MV voltage dip standards for motor starting.
- Automatic electromechanical bypass contactor closes at end of ramp to connect the motor directly to the supply for running, eliminating thyristor losses during the continuous running period and maintaining full DOL running efficiency.
- Adjustable current limit setpoint and ramp time (5–120 s) allows the start profile to be tuned to the specific mechanical characteristics of each driven load — from short-ramp pump starts to long-ramp high-inertia fan starts.
- Soft stop deceleration ramp prevents water hammer in long pump discharge pipelines by reducing motor speed progressively before the discharge valve closes, eliminating the surge pressure that causes pipe joint failures.
- Built-in motor thermistor (PTC/NTC) protection and motor overcurrent protection eliminates the need for a separate motor protection relay in applications where the SL150 is the only starting and protection device in the MV circuit.
- Compact footprint compared to equivalent MV VFD reduces the capital cost and switchroom space requirement for fixed-speed or limited variable-speed MV motor applications that do not justify full VFD investment.
- PROFIBUS and Modbus communication interfaces allow the SL150 start/stop command, speed feedback, and status monitoring to be integrated with the plant DCS or SCADA system without relay logic or separate motor status panels.
Industrial Applications in Saudi Arabia
- Large MV water pump starting at NWC municipal pumping stations, where the SL150 limits MV bus voltage dip during 1.5 MW pump starts on weak grid supply points in rural Saudi Arabia.
- SWCC desalination plant circulating seawater pump starting, where the soft stop ramp prevents pump check valve slam and water hammer in long suction and discharge pipelines following motor trip events.
- Industrial cooling water pump starting at SABIC petrochemical facilities, where 2–4 MW cooling water pumps are started twice daily and DOL starting is prohibited by the on-site 13.8 kV bus fault current contribution restrictions.
- Cement kiln induced draught fan motor starting at Saudi Cement and YACCO plants, where the 120-second ramp time smoothly accelerates the high-inertia ID fan without exceeding the current transformer and starter thermal rating.
- Power plant auxiliary cooling and circulating water pump starting at SEC combined cycle facilities, where the SL150 provides controlled start protection for boiler feed pump and circulating water pump drive motors.
- Aramco crude oil transfer pump starting at tank farm and pipeline terminals, where soft starting eliminates the fluid hammer and mechanical coupling shock that causes frequent coupling and seal failures with DOL starting.
- Mine ventilation fan starting at phosphate mining facilities in Wa'ad Al-Shamal, where the SL150's long ramp time protects the fan motor and belt drive from the mechanical shock of DOL acceleration against high-inertia fan rotor.
Industrial Supplier in Saudi Arabia
Get a Quote for the Siemens SINAMICS SL150 Medium-Voltage Softstarter
We respond within 4 business hours. Send model SL150 for competitive pricing in SAR with delivery across Saudi Arabia and the GCC.
Frequently Asked Questions — SL150
Common questions from buyers in Saudi Arabia and the GCC