External Stop/Start Setup for Multiple VSDs
In some instances, it might be required to Start and Stop multiple motors simultaneously (in some cases it might be required to have a fixed delay between start-ups of the various motors, in which case delay can be set on the DI terminals for the specific VSDs). In order to do that using an external On/Off switch, the VSDs needs to wired to each other with a single On/Off Switch as follows:
Then also set the following parameter on each VSD:
- b0-02 = 1 (terminal control)
Note: If the External Switch has a Normally Closed connection (not Normally Open) the VSD Start/Stop function will operate in the opposite way intended. In this case, also set b3-25 = 00001(Low Level Valid).
Note: If it is required to delay the start of any of the specific motors (Cascade Control), for that motor VSD, set a Start delay on DI1 using b3-15 (DI1 ON delay time). If it is required to delay the stop of any of the specific motors, for that motor VSD, set a Stop delay on DI1 using b3-16 (DI1 OFF delay time).
If these VSDs also need to Stop simultaneously in the event of a Fault occurring on any one of the VSDs, each VSDs Relay output (with Fault Output trigger) also needs to be wired into the circuit as follows:
The also set the following Relay parameter on each VSD:
- b4-03 = 3 (Fault Output)
Please Note: For Smaller Drives with only one set of Relays (TA-TB-TC), use the TA2-TB2-TC2 Relay parameter settings.
Please see example of Large VSD Control Board with 2 sets of Relays below:
* Please Note: If the On/Off Switch is in the On state and a power failure occurs, the VSDs will automatically start again when the power returns (for such a scenario its best to rather make use of a Free Stop Mode for both VSDs and also allow for a Start Delay on the First VSD when the power returns). It is however not ideal to Start/Stop a VSD by switching the power supply On/Off – which is typically the case with regular power failures (causes instantaneous discharge shock impact on capacitors which will reduce the service life of the capacitors) – for a better method of achieving this using an Intermediate Relay, please see the following FAQ Entry: How to Setup an Intermediate Relay to Power a VSD On/Off. A better Stop/Start method for the first VSD would be to use separate Stop and Start Push Buttons as described below:
When using Push Buttons use a 3-Line Mode Stop/Start Setup:
- b0-02 = 1 (Terminal Control)
- b3-13 = 2 (3-Line Mode 1)
- b3-00 = 1 (RUN Enabled) -> DI1 Terminal Connection
- b3-02 = 3 (3-Line Control) -> DI3 Terminal Connection
- 3rd Line Connected to COM
If using FWD/REV as well with above, set:
- b3-13 = 3 (3-Line Mode 2)
- b3-01 = 2 (FWD/REV) -> DI2 Terminal Connection
