The Danfoss MCD500 series is a range of industrial soft starters engineered for demanding and mission-critical applications. The MCD500 provides full control over motor starting and stopping for motors from 7.5 to 800 kW with rated currents from 21 to 1600 A. The series supports two supply voltage classes: 200-440 V and 380-690 V, making it a versatile solution for diverse industrial power networks.

Unlike the basic Danfoss MCD200 series, the MCD500 features advanced capabilities: multiple start profiles (adaptive acceleration torque, voltage ramp, current-limited start), built-in bypass contactor in compact models, cascade control for up to 4 pumps, industrial network interfaces (Modbus RTU, Profibus DP, DeviceNet), and comprehensive motor protection.

Danfoss MCD500 Product Range

The MCD500 catalogue includes 92 models, spanning from compact soft starters for small motors to high-power units for heavy industrial machinery. Below are the key frame sizes (200-440 V voltage class):

Part Number	Power Rating	Rated Current	Supply Voltage
MCD5-0021B-T5	7.5 kW	21 A	200-440 V
MCD5-0053B-T5	22 kW	53 A	200-440 V
MCD5-0105B-T5	55 kW	105 A	200-440 V
MCD5-0245C-T5	132 kW	245 A	200-440 V
MCD5-0927C-T5	500 kW	927 A	200-440 V
MCD5-1600C-T5	800 kW	1600 A	200-440 V

Every model is available in two control voltage variants: CV1 (24 V DC) and CV2 (110-440 V AC), as well as in the T7 version for 380-690 V networks. The complete catalogue of 92 items is available on this page.

Key Advantages of the MCD500 Series

The MCD500 series combines reliability with advanced functionality:

Adaptive start profiles — choose between voltage ramp, current-limited start, and adaptive acceleration torque for different load types.
Cascade pump control — built-in rotation of up to 4 pumps with automatic alternation, ideal for water supply and HVAC systems.
Communication interfaces — Modbus RTU, Profibus DP, DeviceNet, and Ethernet support for seamless automation integration.
Comprehensive motor protection — overload, phase loss, current imbalance, overheating (via PTC/PT100 thermistors), and locked rotor protection.
Energy saving — voltage optimisation to reduce no-load losses in lightly loaded motors.
Built-in bypass — low-power models include an integrated bypass contactor to minimise heat dissipation during operation.

How to Choose a Danfoss MCD500

To select the right MCD500 soft starter, determine the following:

Supply voltage — T5 for 200-440 V networks (standard 380 V) or T7 for 380-690 V networks (industrial high-voltage systems).
Motor power — from 7.5 to 800 kW. The MCD500 part number indicates rated current after the hyphen (e.g., MCD5-0053B = 53 A).
Control voltage — CV1 (24 V DC) for low-voltage control systems or CV2 (110-440 V AC) for direct connection to the control network.
Application type — for pumps choose a model with cascade control, for compressors — one with current-limited start profile.

Other Soft Starter Series

In addition to the MCD500, we offer other soft starter series:

Danfoss MCD200 — cost-effective series for standard applications (18-200 A)
Schneider Electric ATS48 — torque-controlled soft starters for heavy-duty starts
Schneider Electric ATS22 — compact soft starters for pumps and fans

Warranty and Support

All Danfoss MCD500 soft starters purchased from us come with an official warranty. Our engineers can assist with model selection, start parameter configuration, and commissioning. Contact us via the enquiry form or by phone for expert consultation.

Frequently Asked Questions

How is Altistart 22 different from ATS48 and the new ATS480?

ATS22 is the universal base Altistart series with internal bypass; it controls voltage during ramp-up and offers a plain stop ramp. ATS48 adds torque control (TQ-Control) and a full pump stop function for centrifugal pumps, but its bypass is external (a separate contactor in the panel). ATS480 is the new generation and effectively replaces ATS48: TQ-Control, pump stop, plus internal bypass and richer comms (Modbus, optional Profinet / Ethernet IP). For a new pump or conveyor project with torque control, pick ATS480; on new builds the ATS48 no longer makes sense.

How many starts per hour can a soft starter handle?

It depends on whether the unit has an internal bypass. Series with bypass (ATS22, ATS480, Danfoss MCD500, ABB PSR / PSE / PSTX, Veichi SS70) typically take 10-30 starts per hour, because the thyristors switch off after ramp-up and stop heating. Series without bypass (Schneider ATS01, Siemens SIRIUS 3RW30) tolerate 6-10 starts per hour. The exact figure is on the nameplate as AC-53a or AC-53b. If you need over 20 starts per hour with heavy torque, a VFD is more economical than paying for a premium soft starter.

Soft starter or VFD for a pump?

Driven by start frequency and the need to vary flow. If the pump runs in on / off mode by a pressure or level sensor, at up to 10-12 starts per hour, and does not need to hold constant pressure — a soft starter with pump stop (Schneider ATS48 / ATS480, Danfoss MCD500) is two to three times cheaper and fully removes water hammer. If the pump needs to hold network pressure, runs with frequent starts (drainage, sewage), or you need energy savings — pick a VFD with PID. A soft starter gives no savings under steady-state load.

Does a soft starter save energy?

Only on starting losses and through reduced mechanical wear. Under steady-state load the motor is fed straight from the mains via bypass, so consumption matches direct-on-line. Some series (Schneider ATS22, ABB PSTX) offer Inside Delta or Energy Saver, lowering voltage on underloaded motors — but real-world savings are 1-3% and only meaningful on motors permanently running below 50% load. If energy saving is the main goal, the right tool is a VFD with PID, not a soft starter.

What is pump stop and why use it?

Pump stop is a smooth pump-motor stopping function where the soft starter lowers voltage over 10-30 seconds so that pump speed and water-column speed in the pipeline decrease in step. Without pump stop the water column behind the check valve keeps moving by inertia, the valve slams shut and pressure spikes by 5-10 bar — that is water hammer, which breaks valves and welds. The function exists on Schneider ATS48, ATS480, ATS490, ATS430, Danfoss MCD500, ABB PSTX. It does not exist on ATS01, ATS22, MCD200, SIRIUS 3RW30 — these series should not be picked for pump applications.

Do I need an external bypass contactor?

It depends on the series and on start frequency. Series without internal bypass (Schneider ATS01, ATS48, Siemens SIRIUS 3RW30) — an external contactor is recommended for more than 6-10 starts per hour or for 24/7 service; otherwise the thyristors overheat from continuous commutation. Series with internal bypass (ATS22, ATS480, Danfoss MCD500, ABB PSR / PSE / PSTX, Veichi SS70) — no separate contactor needed, bypass engages automatically after ramp-up. The AC-53b figure on the nameplate already accounts for the bypass in start time and duty cycle.

Is a soft starter suitable for frequent starts of a drainage pump?

Usually not. Drainage and sewage pumps cycle dozens of times per hour by tank level — that is 30-60 start / stop cycles. No soft starter series will last that duty: thyristors and internal bypass contactors are typically rated for 10-30 starts per hour. The right tool is a pump VFD (Veichi AC10 with sleep mode, INVT GD20 with PID) running continuously at minimum speed and ramping up when the tank fills — there are effectively no real starts at all.