VSD Input Power Supply Errors
EMHEATER VSD technical specifications regarding the Input Voltage vary depending on the specific model (Input Voltage: 220V/380V/480V/575V/660V ±15%) and typically suggests a 15% variance (recommendation, not limited to). The output voltage will not be affected when the DC Bus Voltage (typically 1.414 x the Input Voltage) is high, but the output voltage will be reduced when the bus voltage is too low. The Power Supply Low/High Voltage Errors thus depend on the actual DC Bus Voltage, with Overvoltage and Under Voltage Thresholds for the various models as listed below:
Overvoltage Thresholds
- G1 Series (Single-phase 220V Supply): Default Overvoltage Threshold = 400VDC
- G13 Series (Single-phase 220V Supply): Default Overvoltage Threshold = 800VDC (Supply Voltage is Doubled for this model)
- G2 Series (Three-phase 220V Supply): Default Overvoltage Threshold = 400VDC
- G3 Series (Three-phase 380V Supply): Default Overvoltage Threshold = 800VDC
- G4 Series (Three-phase 480V Supply): Default Overvoltage Threshold = 890VDC
- G5 Series (Three-phase 525V Supply): Default Overvoltage Threshold = 900VDC
- G6 Series (Three-phase 690V Supply): Default Overvoltage Threshold = 1300VDC
* Parameter bb-28 is used to set the overvoltage threshold for Err05 ~ Err08. Note that the default value is also the upper limit of the VSD’s internal overvoltage protection voltage. The parameter becomes effective only when the setting of bb-28 is lower than the default value. If the setting is higher than the default value, the default value is still applicable.
Under Voltage Thresholds
- G1 Series (Single-phase 220V Supply): Default Under Voltage Threshold = 200VDC
- G13 Series (Single-phase 220V Supply): Default Under Voltage Threshold = 350VDC (Supply Voltage is Doubled for this model)
- G2 Series (Three-phase 220V Supply): Default Under Voltage Threshold = 200VDC
- G3 Series (Three-phase 380V Supply): Default Under Voltage Threshold = 350VDC
- G4 Series (Three-phase 480V Supply): Default Under Voltage Threshold = 450VDC
- G5 Series (Three-phase 525V Supply): Default Under Voltage Threshold = 450VDC
- G6 Series (Three-phase 690V Supply): Default Under Voltage Threshold = 650VDC
* Parameter bb-29 is used to set the under-voltage threshold for Err09 (or Err08). If the power supply voltage is low on ad hoc basis but generally return to normal, this parameter can be adjusted slightly, but if the voltage is consistently low, it is not recommended.
* Note that Err12 (Power Input Phase Loss) could also occur due to a Power Supply Overvoltage or Under Voltage.
Surge Protection
To protect the VSD against power supply deviations and surges all EMHEATER VSDs include a Protection Board with Shunting Capacitors (for Electromagnetic Interference Suppression – like used in EMI Filters) and Varistors (for Voltage Suppression – also known as Voltage Dependent Resistors – VDRs).
Shunting Capacitors typically redirect current in a specific range, high frequency, away from a circuit or component and feeds the high frequency current/interference into inductors that are arranged in series, and as the current passes through each inductor, the overall strength or voltage is reduced. Optimally, the inductors will reduce the interference to nothing (also called shorting to ground).
Varistors has an electrical resistance that varies with the applied voltage and when a voltage surge exceeding a specified voltage is applied, the varistor suppresses the voltage to protect the circuit.
The Protection Board thus protects EMHEATER VSDs against electromagnetic interferences and power supply surges. Damage to the Protection Board could occur due to a very excessive power surge (more than 685Vac phase to ground) via the power supply in which case it would most likely also damage many of the other components in the rest of the power circuit.
