VSD Dry Run Protection Setup
To setup a Low Current Alarm (typically used for Dry Run Protection for Water Pumps), the following parameter settings can be used:
- Set b7-00 (VDI1) = 38 (Normally Open input of external fault – this is to specify the Virtual Digital Input to give an Error when triggered by the Virtual Digital Output) – the default for b3-04 = 38 and first needs to be set to a different value to allow setting b7-00 = 38 – only one terminal can use a value at a time)
- Set b7-11 (VDO1) = 26 (Zero current state – this is to set the Virtual Digital Output to trigger a zero current state output)
- Set b4-31 (Zero current detection level) = set below current value (% of motor current as set using d0-02) – this is to define the current value to be used as the Zero Current (Low Current) trigger
- Set b4-32 (Zero current detection delay time) = delay protection time – this is to define for how long the current value can be below the Zero Current (Low Current) before initiating a trigger event
When the Low Current Alarm is triggered the VSD will show Err15: External Equipment Fault (External fault signal via virtual I/O). In some cases it might be required to set the VSD to automatically restart again after a delay period. This requires that the VSD is set up to clear the Error to allow the Auto Restart. This can be done as described in the following FAQ entry HERE.
* Please Note: For VSDs up to 55kW using software versions before V0.12 (released 15 Sept 2022), the B4-31 current value of 10% = d0-02, for version V0.12 and later the B4-31 current value of 100% = d0-02 for all VSD kW ranges.
For scenarios where this setup might be applicable, please see:
– To set up a EMHEATER VSD with a Pressure Transmitter to provide Constant Water Pressure using the VSD Parameters to set a Fixed Target Pressure, please see the relevant FAQ entry HERE.
– To set up a EMHEATER VSD with a Pressure Transmitter to provide Constant Water Pressure using an external analog signal (such as a PLC) to modify the target pressure (Variable Target Pressure), please see the relevant FAQ entry HERE.
– To set up a EMHEATER VSD with a Pressure Transmitter to provide Constant Water Pressure using an external Multi-Stage Switch to modify the target pressure (Target Pressure Selector), please see the relevant FAQ entry HERE.
– To set up a EMHEATER VSD with a Pressure Transmitter for Frequency Control using a PID (Manage Water Outflow), please see the relevant FAQ entry HERE.
– To set up a EMHEATER VSD with a Pressure Transmitter for Frequency Control using a PID (Manage Water Inflow), please see the relevant FAQ entry HERE.
– To set up a EMHEATER VSD with AI Input Overrun Limit (using a Pressure Transmitter as STOP), please see the relevant FAQ entry HERE.
For additional Protection Features, please also see:
– To set up a EMHEATER VSD End of Curve Parameters (PID Signal Loss Protection), please see the relevant FAQ entry HERE.
– To set up a EMHEATER VSD Restart (Delayed) after Low Current Protection Condition Occurred (Dry Run Protection Reset), please see the relevant FAQ entry HERE.
