More actions
| Simovert VC 6SE7021-8EB21-Z Incorrect DC link voltage reading repair | |
|---|---|
| Device | Simovert VC 6SE7021-8EB21-Z |
| Affects part(s) | Measure resistor |
| Needs equipment | multimeter, soldering iron, soldering station |
| Difficulty | ◉◉◉◌ Hard |
| Type | Soldering |
Problem description
Repair of a problem where the rectified DC link voltage reading is incorrect on this Siemens Simovert VC inverter.
Symptoms
- Incorrect DC voltage reading
- Measuring with MM yields correct voltage but the inverter measures it incorrectly
- Inverter won't run and low DC voltage error
Solution
On the power board, there is a vertical ceramic resistor that houses 2 resistors inside (figure 1). Desolder it out and measure both resistors, they should measure the same, if not, you'll need to replace the resistor with an external one. Make sure to use a 1% or less tolerance.