Frequency inverter ER41

The most important advantages:

- Sustainable cost savings
- Increased service life
- Energy saving


A perfect set of BLEMO® - for all applications.


Frequency inverter for speed adjustment of DS asynchronous motors and synchronous motors, 0.75 to 800.0 kW, 380 to 480 V, 3~protection class IP21 to IP55.

ER41K – IP21 – Control cabinet mounting


This new range replaces the ER40. The ER41’s programmable and optional capabilities are virtually unlimited. The device can be used for all applications in machine and plant construction, both for variable and constant torque applications. The development was carried out under the latest aspects of relevant standards and international regulations, including EMC and environmental compatibility, e.g. RoHs, WEEE.

Standard features

  • Multilingual operator terminal with real-time clock and USB connection
  • built-in PID controller
  • Integration of the real pump curve
  • Integrated Modbus/TCP, serial Modbus interface, Ethernet
  • Integrated EMC filter, line choke
  • Output filter up to 300m motor cable length, shielded
  • PTC thermistor input PTC, PT100, PT1000, KTY84
  • Integrated STO function, SIL3/Ple, two-channel
  • RoHs, WEEE compliant (recycling rate 88%)
  • Fieldbuses: Ethernet/IP and Modbus/TCP with two ports, CANopen,Profibus DPV1, Profinet, DeviceNet


  • Version 1: Basic device without built-in load-break switch IP55
  • Version 2: Basic unit with built-in load-break switch IP54
  • Version K: For control cabinet IP21

Device versions

The ER41 is available in two versions ER41-…K, protection type IP21/23 and ER41-…G, protection type IP54/55 with(-V2) and without(-V1) switch-disconnector. The units are supplied from the factory with painted circuit boards. Units from 90 kW are additionally equipped with tinned copper bars (optional for smaller outputs), for aggressive air.

Better pump protection with the ER41

your benefits

Areas of application

Frequently asked questions about the product

1. a connection must be made between +24 and DI1 (clockwise rotation).

  1. To achieve electromagnetic compatibility, the inverter must be operated with a built-in or external RFI filter.

  2. When using shielded cables between the inverter and the motor, the shield must be connected to earth at both ends. Cable interruptions should be avoided as far as possible. If it is necessary to separate the cable, e.g. in order to install a motor contactor, then the cable shielding must be connected through as directly as possible. It is important to ensure that the lowest possible HF impedance is achieved.

  3. The shorter the cable, the lower the radio interference and leakage current. The maximum possible cable lengths must be taken into account.

  4. To avoid interference with the control inputs, control cables should always be shielded. The shield must be connected to the cable clamp provided on the inverter. If the shield is also connected to a control unit, ensure that the ground points are at the same potential.

  5. Control cables should not cross power cables if possible. Where this cannot be avoided, a right-angle intersection is recommended.

  6. Separate routing of control and power cables should be aimed for. If the cables have to be laid in parallel, e.g. on the same cable route, the greatest possible distance (> 20 cm) should be chosen.

  7. The shielding of the installed cables should have a low RF impedance if possible. Therefore, copper braiding is preferable to steel braiding.

  8. The HF contact resistance at the connection points between the shielding and the housing must be kept as low as possible. Dirt, paint and insulation residues on the housing and shielding in the area of the connections must therefore be removed. In principle, the cable clamps or crimp connections provided for this purpose should be used to connect the shielding. The use of earthing glands is advantageous.

  9. The shielding should be applied to the housing as close as possible to the cable terminals. Longer, free cable ends act as antennas.

  10. For unshielded cables, the cable cores should be twisted and output filters should be used.

1. Select quick start

2. there you will find some parameters, like ramp-up time or high speed.

1. +10V to AI1 and ground to COM.

1. 5. complete setting.

2. 5.9 General Functions => PID controller (Here you will find all the necessary parameters for setting the PID controller)

1. 5. complete adjustment.

2. 5.9 General Functions => HMI command => Shock-free

1. 5. complete setting.

2. 5.9 General Functions => Preset. Speeds => 2 Preset. Frequency = e.g.DI3

3. Then set the speeds in: Preset. Speed 2 => e.g. 25 Hz etc.

Please refer to the table on page475 in the programming instructions.

1. 5. complete setting.

2. 5.5 Command and setpoint => Parameter type 2-wire- Ctrl. => Set value level.

1. 5. complete setting.

2. 5.5 Command and setpoint => Parameter type 2-wire- Ctrl. => Set value level.

To adjust and change the motor speed display on the ER41 drive, perform the following steps:

1. 8. my attitude

2. 8.4 Adjustment

3. adjust parameters

4. DCP

5. back to 4. display

6. 4.4 Motor parameters

7. select motor speed

8. adjust parameters and user def. Click on selection

9. select motor speed with desired unit

1. 5 Complete setting

2. 5.5 Command and setpoint

3. assign. reverse sequence

4. please use DI2 for counterclockwise rotation

In principle, it is possible to operate a motor with low power on a frequency inverter with higher power.
The ratio between motor and inverter power is important here.
Experience shows that the ratio of 1:4 should not be exceeded.

For example, it is not recommended to operate a 0.75kW motor with a 30kW BLEMO frequency inverter.
This combination can be used for test purposes, but the motor phase monitoring must be deactivated.