Scope of this technical record
Danfoss VLT Alarm 14 routing for users deciding whether the earth-fault indication is caused by motor/cable insulation, moisture, output terminal contamination, output IGBT path, current feedback or repeated module repair conditions.
Do not insulation-test through the VLT drive and do not repeatedly restart into a suspected earth fault. Isolate motor and cable correctly, verify discharge and follow qualified test procedure before output work.
Danfoss Alarm 14 earth-fault route
Alarm 14 must be proven through motor/cable behaviour before current-sensor or output-stage repair.
Danfoss Alarm 14 earth-fault image
Searcher intent coverage
Alarm 14 users need to know whether the earth fault follows the motor/cable or remains inside the drive current-sense/output path.
| Observed situation | Decision needed | Evidence that satisfies the search |
|---|---|---|
| Alarm with motor connected | Motor or cable insulation | Insulation readings and terminal photos |
| Alarm after rain/washdown | Moisture route | Environmental pattern and cable gland evidence |
| Alarm with output disconnected | Drive-side boundary | Disconnected-output result and current-sensor route |
What Alarm 14 users really need
Most Alarm 14 searches are urgent: the VLT reports earth fault, and the user wants to know whether the motor is wet, the cable is damaged, or the drive power stage is bad. The page must start outside the drive because earth-fault symptoms are often created by motor terminal moisture, damaged cable insulation, cable glands, long contaminated runs or external leakage.
The repair boundary changes if Alarm 14 remains with the motor/cable isolated under a safe procedure. At that point the route moves inward toward output IGBT path, current feedback or sensing hardware. This is where your repair material is valuable: repeated module failures are often caused by missed driver/sensing/cause checks, not by a bad replacement part alone.
Alarm 14 timing map
| When Alarm 14 appears | Most likely first boundary | Evidence to collect |
|---|---|---|
| Immediately at enable | Output terminal, motor cable, ground leakage or internal output stage | Motor/cable isolation and terminal inspection |
| After humidity/washdown | Motor terminal box, cable glands, contamination tracking | Photos and insulation evidence after drying/inspection |
| Only under load or vibration | Cable movement, insulation breakdown, motor winding stress | Cable route, movement, load timing |
| After motor/cable work | Wrong connection, damaged insulation, shield/PE issue | Before/after wiring photos and insulation test |
| After module repair | External cause or driver/current feedback missed | Prior repair report and driver/sense evidence |
Safe checking sequence
Record the VLT type code, alarm number, trip timing and environmental condition. Inspect the motor terminal box, cable glands, conduit, cable route and output terminals before assuming an internal drive fault. Moisture and contamination can create leakage paths that look like a drive problem from the keypad.
Next isolate motor and cable correctly. If the alarm clears when the external output path is removed, continue outside the drive. If the alarm remains after the output path is safely isolated and the procedure is valid, the power-stage/current-sense boundary becomes credible. Do not run a replacement drive or module on the same motor/cable until the earth-fault route is corrected.
Alarm 14 evidence split
| Evidence | External route stronger | Drive-side route stronger |
|---|---|---|
| Insulation fault found in cable/motor | Yes | No internal conclusion yet |
| Wet or contaminated terminal box | Yes | Drive likely responding correctly |
| Alarm clears with output isolated | Yes | Internal route weak |
| Alarm remains with output safely isolated | External route weaker | Output bridge/current sensing route stronger |
| Repeated after power-stage replacement | External cause or driver/sense route unresolved | Internal repair must include cause check |
What a useful VLT Alarm 14 request includes
A useful request includes full VLT type code, alarm number, when it appears, motor/cable insulation result, terminal-box photos, environmental condition, cable route, grounding/shield information and prior repair history. If Alarm 14 appears alongside Alarm 16 short circuit or DC-link faults, preserve the sequence before resetting.
This page should not promise a single cause. It should give the user a decision: external motor/cable repair, installation cleanup, controlled isolation test, or drive-side power-stage/current-sense investigation. That is the depth missing from many short alarm lists.
Alarm 14 stop conditions
| Condition | Why to stop | Next action |
|---|---|---|
| Motor/cable not isolated | Drive-side conclusion is premature | Perform qualified isolation procedure |
| Moisture or contamination visible | Repeat starts can worsen tracking | Clean/dry/repair external path first |
| Alarm remains with output isolated | Possible internal sensing or output path | Escalate with controlled test evidence |
| Previous module repair undocumented | Repeat failure risk | Collect driver/current-feedback and external cause evidence |
Field record checklist
- Full Danfoss VLT type code and frame/rating
- Exact alarm text/number and fault-history sequence
- Trip timing and environmental condition
- Motor terminal box, cable route and output terminal photos
- Motor/cable isolation and insulation evidence
- Whether alarm persists with external output path safely isolated
- Previous power-stage, driver or current-sense repair history
Technical basis and reference documents
This is an independent editorial technical reference. Original manufacturer documentation remains controlling for installation, repair and commissioning decisions.
Alarm 14 output-earth-fault routing built from VLT alarm structure and uploaded inverter repair experience.
Used for repeated module failure, driver/small-component and false external/internal boundary guidance.