The implementation of this protection is easy. Overcurrent Protection Either circuit breakers or fuses can be used as the overcurrent protection for a VFD. Thread starter philly; Start date Jun 22, 2010; Status Not open for further replies. An overcurrent protection device is required in the AC supply to the VFD. intended to protect an electric circuit or parts of an electric circuit . Over-current is caused … VFD tripping on instantaneous overcurrent. The causes may include: The motor suffers an impact load or the transmission mechanism is stuck, which leads to sudden increase of the motor current. Next Last. However, fuses can drop out one leg of a three-phase circuit and cause damage to a motor if not properly equipped with phase-loss detection.
Overcurrent protection is a basic protection that shall always be included, regardless what type of transformer you have or what application it is. A protection provided by a device which is. how to decide the amps of the overcurrent protection for the VFD controlled motor? Looking to install a 50HP VFD for a Chilled Water Pump. If IPM module overcurrent or ground wire short circuit causes the VFD trip in deceleration, generally it's the top half-bridge module or drive circuit fault; If IPM module overcurrent during acceleration, then it is the next half-bridge module or drive part fault.
The VFD has an internal DC link with capacitors designed for rated current. So if an environment calls for protection from liquids (whether it’s directed from a hose or falling from above) then using a NEMA Type 1 enclosure will surely lead to a very early dirt nap for the VFD. mike883: General Electrical Discussion: 18: 08-09-2016 01:05 AM: Overcurrent Protection for Panels: JasonCo: NEC Code Forum: 5: 02-01-2016 11:03 PM: overcurrent protection on secondary side of transformer: Steve W: General Electrical Discussion : 3: 01-06-2016 11:38 PM: All times are GMT -4. A VFD can be programmed to provide thermal protection for each of these motor designs. A motor branch circuit, including a Variable Frequency Drive (VFD ) and one or more Motor Protection Circuit Breakers (MPCBs), is a complex system and its performance depends on all co mponents, devices, configuration and their interconnection.
The purpose of this device is twofold: To provide thermal protection for the VFD cables etc between the location of the overcurrent protective device (usually at the origin of the relevant supply sub-circuit) and the VFD. I'm a little old school and always protect my motors at 175% assuming I'm using a thermally protected breaker or time delay fuses. What is Overcurrent (OC) protection? 12-10-2007, 11:14 PM #3. 1; 2; Next. 50HP 3-phase 65amps @460v 65amps @ 125% = 81.25amps or 90amp … This allows the drive to function as an overcurrent device, and the drive will then trip on excessive current.