Sequential Starting for Drives
A Leader-Follower (Master/Slave) application is where two or more drives are electronically synchronised (Cascade Control). Typically, the first drive is configured as the “Leader” or “Master” and the subsequent drive/s that follow the master are referred to as the “Slaves” or “Followers”.
To use one Drive’s Running Frequency (Drive 1 = Leader) as a reference point to specify when another Drive (Drive 2 = Follower) should start, please connect the Drives and set the required parameters as follows:
Connections:
To ensure each Follower Drive can only activate once the Drive before it in the sequence has reached a desired speed (Set Frequency Reached), each Follower Drive’s digital input (used for Run Command – Terminal Control Mode) will be connected to the Drive before its Relay Output (which is set to switch on once the drive before it reaches the required speed).
The Leader Drive will have a manual On/Off switch to start the system (the example includes a Intermediate Relay as well in order to quickly switch off the system during power failure to prevent Power Failure Errors and also to protect the Drives – this would not be applicable for Solar Drives).
Parameter Settings (VSDs and Solar Drives):
All drives will use Terminal Control as starting method: Set b0-02 = 1 / F0-02 = 1
- Leader:
- Set b4-02 = 17 / F5-04 = 3 (Relay to Switch when Frequency-level Detection FDT1 Output has been reached)
- Set b4-22 / F8-19 = Desired speed (Hz) which should trigger the next drive to start
- Follower 1:
- Set b4-02 = 17 / F5-04 = 3 (Relay to Switch when Frequency-level Detection FDT1 Output has been reached)
- Set b4-22 / F8-19 = Desired speed (Hz) which should trigger the next drive to start
- Follower 2:
- Set b4-02 = 17 / F5-04 = 3 (Relay to Switch when Frequency-level Detection FDT1 Output has been reached)
- Set b4-22 / F8-19 = Desired speed (Hz) which should trigger the next drive to start
For more information regarding the use of VSDs for Leader-Follower applications, please our blog entry HERE.
For setting up Leader-Follower VSD Speed Synchronisation (Cascade Control), please see FAQ entry HERE.
