Troubleshooting a low voltage trip (LVT)

Troubleshooting a low voltage trip (LVT)

A low voltage trip occurs when the DC bus voltage drops below the trip point. It is important to note that the VFD does not directly measure input voltage. The VFD measures DC bus voltage. In turn, if DC bus voltage drops, it can be assumed that the supply voltage has dropped. Reference to the below flowchart for possible causes.

200V Class trip point = 180VDC
400V Class trip point = 380VDC