Danfoss VLT series

Control characteristics
Resolution of output frequency at 0–590 Hz ±0.003 Hz
Repeat accuracy of precise start/stop (terminals 18, 19) ≤±0.1 ms
System response time (terminals 18, 19, 27, 29, 32, 33) ≤2 ms
Speed control range (open loop) 1:100 of synchronous speed
Speed control range (closed loop) 1:1000 of synchronous speed
Speed accuracy (open loop) 30–4000 RPM: error ±8 RPM
Speed accuracy (closed loop), depending on resolution of feedback device 0–6000 RPM: error ±0.15 RPM
Torque control accuracy (speed feedback) Maximum error ±5% of rated torque
All control characteristics are based on a 4-pole asynchronous motor.
Protection and Features
•
Electronic motor thermal protection against overload.
•
If the temperature reaches a predened level, temperature monitoring of the heat sink ensures that the frequency
converter trips. An overload temperature cannot be reset until the temperature of the heat sink is below the values
stated in the tables in chapter 5.6 Electrical Data (Guideline - these temperatures can vary for dierent power sizes,
enclosure sizes, enclosure ratings, and so on).
•
The frequency converter is protected against short circuits on motor terminals U, V, W.
•
If a mains phase is missing, the frequency converter trips or issues a warning (depending on the load).
•
If the DC-link voltage is too low or too high, monitoring of the DC-link voltage ensures that the frequency
converter trips.
•
The frequency converter constantly checks for critical levels of internal temperature, load current, high voltage on
the DC link, and low motor speeds. As a response to a critical level, the frequency converter can adjust the
switching frequency and/or change the switching pattern to ensure the performance of the frequency converter.
General Specications Operating Instructions
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