Complete Guide to Lenze ECS Servo System

Complete Guide to Lenze ECS Servo System

In the field of modern industrial automation, multi axis high dynamic drive tasks impose strict requirements on the power density, response speed, installation flexibility, and long-term reliability of servo systems. The Lenze ECS servo system is designed for this purpose - it integrates high overload capacity, compact structure, multiple installation forms, and rich software functions, and can be widely used in handling robots, packaging machinery, gantry systems, machining centers, and other occasions. This article systematically elaborates on the hardware selection, power calculation, braking energy management, EMC countermeasures, software configuration, and common troubleshooting methods of Lenze ECS servo system from the perspective of engineering practice, providing a practical technical manual for on-site engineers and technical support personnel.

System Overview: Why Choose ECS Servo System

The Lenze ECS servo system is a multi axis servo drive solution based on DC bus sharing. Its core features include:

Extremely high overload capacity: The peak current of the shaft module can reach 4 times the rated current (such as ECSx032 with a maximum output current of 32A and a rated current of 12.7A), meeting the requirements of rapid acceleration, deceleration, and impact load.

Multiple installation forms: support built-in control cabinet (build in), push through technology (push through, external heat sink), and direct installation of cold plate to adapt to different heat dissipation conditions.

Integrated safety function: All axis modules come standard with the "Safe Torque Off" function, which complies with EN 954-1 control category 3 and allows for safe shutdown without the need for additional safety relays.

Flexible software features: ranging from simple speed/torque control to programmable positioning, electronic cam, winding control, and even preset flying shear and cross cutting solutions, covering various typical processes.

The most common confusion encountered by engineers when facing multi axis systems includes: how to choose the capacity of the power module? How to determine if a capacitor module is needed? What is the appropriate size for the braking resistor? How to suppress encoder interference? This article provides answers one by one.

Hardware selection and power calculation

2.1 Selection steps of axis module

The correct selection of axis modules requires starting from mechanical load data and following the steps below:

Determine load parameters: 

Calculate maximum torque M max

Maximum speed n max

Effective torque Meff

For systems with reducers, a reduction ratio is also required ii。

Select servo motor: Based on the above parameters, choose the appropriate motor from the Lenze MCS (synchronous motor), MDCKS, MCA, or MDFQA (asynchronous motor) series. Specific data can refer to the 'Servo Motor Product Catalog'.

Determine the model of the shaft module: The selection of the shaft module is determined by the maximum current and continuous power. The overload mode of the ECS axis module is: within a 3-minute cycle, the maximum output current during the 1-minute load phase can reach 150% of the rated current (some low-power models can reach 200%), and during the 2-minute recovery phase, it reaches 75% of the rated current.

Rated data of ECS axis module (400V system, 8kHz switching frequency)

Model Rated DC bus current (A) Rated output current (A) Maximum output current (A) Power consumption - Internal module (W) Power consumption - Heat sink (W)

ECSx004 2.5 2.0 4.0 13.3 14

ECSx008 4.9 4.0 8.0 17.3 29

ECSx016 9.8 8.0 16.0 20.7 64

ECSx032 15.6 12.7 32.0 27.5 117

Note: The actual output current can be increased by 26% to 35% under specific control factors.

2.2 Calculation of Power Module and DC Bus Capacity

In a multi axis system, all axis modules share the same DC bus. The power module must provide the sum of the average power of all axes and have sufficient peak power capability. In practice, it is recommended to draw a "time power diagram" of the entire machine cycle, superimposing the transient power of each axis to obtain the total power curve.

Power module model and data

Rated DC bus current of power module (A) Applicable voltage range Integrated braking chopper Continuous braking power (kW)

ECSEE012 12 3 AC 180~550V has 0.1

ECSEE020 20 3 AC 180~550V has 0.1

ECSEE040 38.5 3 AC 180~550V with 0.1

2.3 Criteria for Capacitor Modules

In dynamic multi axis applications, the DC bus may generate significant ripple or even undervoltage due to instantaneous energy exchange. Lenze provides ECS capacitor modules (ECSZK series) for increasing bus capacitance. A simple and practical criterion is as follows:

k=C total P avg

k= P avg C total

among which C total

The sum of the DC bus capacitors inside all axis modules (in μ F),Pavg

The average total power (in kW) of all drives. if k≥one hundred μ F/kW k≥100 μF/kW， Usually, no additional capacitor module is required; Otherwise, it is recommended to install it.

For example, the system has 4 ECSx016 axis modules, each with an internal capacitance of 165 μ F and a total capacitance of 660 μ F; If the average total power is 5kW, then k=six hundred and sixty/five=one hundred and thirty-two>one hundred k=660/5=132>100， No capacitor module is required. If the capacitance is only 300 μ F, the power is 6kW, and k=50<100, then the installation of ECSZK capacitor module should be considered.

Installation method and heat dissipation design

There are three installation forms for ECS servo system, and engineers should choose based on the control cabinet space and heat generation:

Built in: The module is directly installed on the control cabinet mounting board, and all heat is dissipated inside the cabinet. Suitable for situations with low power or good ventilation inside the cabinet.

Push through technology: The heat sink of the module passes through the back panel of the control cabinet and is exposed to the external environment of the cabinet. About 65% of the losses are dissipated through external heat sinks, with only 35% remaining inside the cabinet. It can significantly reduce the temperature rise inside the cabinet, and even eliminate the need for air conditioning or fans. When ordering, the corresponding model (such as ECSxX032-PT) should be selected.

Cold plate: The module does not come with a heat sink and relies on the user's system's cooling plate (such as a water-cooled plate or large metal structure) for heat dissipation. Suitable for high-density integration or extreme environments.

Key dimension reference (ECSx032):

Built in: height 247mm, width 88mm, depth 176mm, weight 2.2kg

Cold plate: height 287mm, width 88mm, depth 121mm

Installation gap requirement: Maintain a ventilation distance of at least 100mm up and down. In the push through technology, the opening size of the control cabinet must strictly follow the cutting diagram in the product manual to ensure the IP54 protection level (radiator side).

Braking energy management

When the motor decelerates or the load is lowered, energy is fed back to the DC bus, causing an increase in bus voltage. The ECS power module is equipped with a built-in brake chopper, which automatically turns on the external brake resistor when the bus voltage exceeds the threshold (typical value of 765V), converting excess energy into heat consumption.

4.1 Selection of Braking Resistors

Lenze offers three types of braking resistor series:

ERBD: IP20 protection, installed inside the control cabinet, suitable for general occasions.

ERBS：IP65， Can be installed outside the cabinet to avoid temperature rise inside the cabinet.

ERBM：IP50， Specially designed for cold plate power modules, with the same size and internal resistance as the module.

Selection suggestion: Select the corresponding resistor based on the rated DC bus current of the power module. For example, ECSEE012 recommends using ERBD047R01K2 (47 Ω, 1200W continuous, heat capacity 174kWs) or ERBS039R01K6 (39 Ω, 1600W). For high vibration environments such as stacker cranes, the anti vibration ERBDV series should be selected.

Minimum resistance limit: When using external braking resistors, the resistance value must not be lower than the minimum value specified by the power module (usually 27 Ω± 10%). A low resistance value can cause overcurrent damage to the chopper tube.

4.2 Continuous braking power and thermal capacity

In the technical parameters of braking resistors, "continuous power" (P) represents the long-term tolerable power, and "thermal capacity" (CB) represents the short-term energy absorption ability. For intermittent braking conditions, it is necessary to calculate the energy of each braking operation（

E=zero point five×Cbus×(Umax two−Umin two)

E=0.5×C bus×(U max two−U mintwo）Add motor kinetic energy and ensure that the single braking energy does not exceed the CB value of the resistor, and the average power does not exceed P.

For example, ECSEE012 with ERBD047R01K2, CB=174kWhs. If the braking energy is 50kWs, it is completely within the safe range. The average power needs to be verified during frequent braking.

EMC Countermeasures and Filter Configuration

Servo systems are typical sources of interference. The Lenze ECS system provides graded EMC solutions for different electromagnetic environments.

5.1 Power side filter

According to EN 61800-3 standard:

Class C1: Used for public low-voltage power grids (residential areas). ECSZZ series RFI filters are required, allowing for a maximum length of 25m shielded motor cables (up to 10 axes).

Class C2: Used in industrial areas, but may affect residential areas. Generally, Lenze standard power filters can be used.

Specific configuration: When using ECSEE power modules, ECSZZ020X4B (20A) or ECSZZ040X4B (40A) RFI filters should be matched. The filter should be installed close to the power module and well grounded.

5.2 Incoming Reactor (Main Reactor)

Even if strict EMC is not required, it is strongly recommended to connect the incoming line reactor (ELN3 series) in series in the main circuit. Its functions include:

Improve input current waveform and reduce harmonic distortion rate

Reduce the impact on the power grid and improve the power factor

Reduce the AC load on the electrolytic capacitor of the DC bus and extend the lifespan of the driver

Selection example: ECSEE012 power module corresponds to ELN3-0150H024 (24A), ECSEE040 corresponds to ELN3-0055H055 (55A).

5.3 SinCos Encoder Interference Filter

When the motor cable is long (>25m) or the on-site grounding is not ideal, the encoder signal may be interfered with, causing position jitter or runaway. Lenze provides the EZZ0014 interference filter (9-pin Sub-D adapter), which can be directly installed on the encoder input interface to effectively suppress common mode interference.

Control connection and fieldbus

The control terminals of the ECS servo system adopt a plug-in design (maximum 1.5mm ²). The main interfaces include:

1 analog input: ± 10V or 0-20mA, 11 bits+symbol resolution

4 digital inputs: compliant with IEC 61131-2, 24V level

2 digital outputs: 1 50mA, 1 1.5A (can directly drive small brakes)

2 CAN bus interfaces: Supports CANopen protocol, with a minimum cycle time of 1ms, used for multi axis synchronization

1 AIF expansion slot: capable of inserting communication modules such as Profibus, DeviceNet, Interbus, LECOM, etc

Encoder interface: 9-pin Sub-D, supports SinCos/TTL incremental encoder, Hiperface absolute encoder (single/multi turn)

Engineering Tip: Digital frequency input/output (two tracks) can achieve electronic gear synchronization between multiple axes without the need for upper level controller intervention. In the installation of push through or cold plate, it is necessary to use the original Lenze shielding connection kit ECSZS000XOB001 to ensure reliable high-frequency grounding.

Software Features and Application Solutions

The ECS servo system is divided into three versions according to control requirements:

Speed&Torque: Pure speed/torque control, supporting 15 preset speeds, S-shaped acceleration and deceleration, and motor brake logic.

Motion: Angle synchronization based on CAN motion bus, suitable for electronic camshafts (master-slave following).

Application: Fully programmable, supports five languages of IEC 61131-3 (IL, LD, FBD, ST, SFC), can load the following software packages:

7.1 Positioner software package

Up to 128 positioning configurations, can be executed in any order

Support absolute, relative, and modular positioning

Jerk limitation, speed/acceleration multiplier, target position reaching tolerance

16 reset modes with Teach in function

Application: Material transfer, stacking, rotating worktable, robot

7.2 Cam software package (Cam)

Up to 48 cams, with a maximum of 4096 interpolation points per cam

Virtual spindle supports jog, handwheel, periodic operation, and automatic mode

Online stretching, compression, phase shift cam curve

Built in Cam Designer Basic Edition for graphically creating motion curves

Application: contour machining, filling, packaging, cross cutting

7.3 Winder software package for winding machine

Three modes: open-loop tension control, closed-loop tension control, and dance roller control

Automatically calculate roll diameter, inertia, and friction compensation

Acceleration torque feedforward, material density self identification

Application: Central winding/unwinding (cable, textile, paper, film)

7.4 Prepared Solutions

Flying cutter: The processing tool synchronizes with the material movement and returns after cutting is completed. Suitable for fixed length cutting, printing, and marking.

Cross cutting: The rotating knife drum synchronizes with the material during cutting phase, supporting color correction, gap control, and continuous/asynchronous cutting.

These solutions can serve as extension functions for ECSA (Application) controllers, greatly reducing programming and debugging time.

Engineering software and debugging tools

8.1 Global Drive Control (GDC)

GDC is Lenze's traditional parameter setting and diagnostic software, characterized by:

Short Setup Wizard to quickly complete basic parameters

Function Block Editor (interconnecting function blocks without programming knowledge)

Built in oscilloscope (multi-channel recording, trigger conditions can be set)

Supports LECOM, CAN system bus, USB adapter (EMF2177IB) communication

The free version of GDC easy can be downloaded from the Lenze website, and the paid single user license ESP-GDC2 provides all features.

8.2 Drive PLC Developer Studio (DDS)

Integrated development environment for programming ECS Application and 9300 Servo PLC:

Support IL, LD, FBD, ST, SFC, and CFC editors

Online debugging, breakpoints, variable monitoring, simulation

Seamless integration with GDC and GD Oscilloscope

It is recommended to purchase the professional version (ESP-DDS2-P) to obtain the CFC editor and graphical visualization.

8.3 Global Drive Oscilloscope

Without the need for external measuring instruments, 8 channels of variables (speed, torque, current, position error, etc.) can be directly collected from the drive memory. The sampling time can be configured and recording before/after triggering is supported. It is very practical for optimizing control loops and analyzing mechanical resonance.

8.4 Cam Designer and Cam Loader

Cam Designer: Graphically create cam curves, supporting VDI 2143 motion patterns (polynomial, modified sine, trapezoidal acceleration, etc.), with a maximum of 4096 points per curve.

Cam Loader: Download cam data to multiple target systems, support scripting batch download, suitable for end-user recipe management.

Common troubleshooting (engineering experience)

Possible causes of malfunction and troubleshooting steps

The driver has no response when powered on, and the 24V control power supply is missing; The DC bus has not been established to check the auxiliary power supply wiring; Measure the input voltage of L1/L2/L3; Confirm that the power module enable terminal is closed

The motor does not rotate and no alarm enable signal is given; The limit switch has not been reset; Check the status of the digital input "Controller Enable" when the brake is not opened; Use GDC to monitor status words; Manual release brake test

During operation, if the DC bus voltage exceeds the upper limit (about 820V) and reports "overvoltage", check if the braking resistor is disconnected; Measure whether the chopper is triggered; Reduce deceleration; Add capacitor modules to absorb energy

Motor shaking or abnormal noise, encoder interference; Excessive gain; Mechanical resonance inspection encoder cable shielding layer grounding (single end); Install EZZ0014 filter; Reduce the gain of the speed loop P; Use notch filter

The gradual accumulation of multi axis synchronization errors results in insufficient accuracy of the electronic gear ratio; CAN communication packet loss using floating gear ratio; Check the CAN terminal resistance (120 Ω); Shorten the communication cycle to below 2ms

The braking resistor is overheating and smoking, and the braking is too frequent; Insufficient resistance power; Calculate the average braking power if the bus voltage does not reach the chopping threshold, and use a larger continuous power resistor instead; Check the chopping threshold parameter (default normal)

Driver reports "DC bus undervoltage" and the power grid drops instantly; Insufficient capacity of power module to use external DC support capacitor; Increase the incoming reactor; Check if the three-phase power supply is missing phase