Introduction
In industrial production, variable frequency drives (VFDs) are the core equipment for motor control and regulation. The Schneider ATV310 series is widely applied in fans, pumps, and conveyors due to its cost-effectiveness and stable performance. However, many users encounter the situation where the drive display shows “–00.” For operators unfamiliar with this model, this display may be mistaken as a fault or equipment failure. In fact, “–00” is not an error, but a normal status indication. This article explains the meaning of “–00,” analyzes the causes, discusses typical scenarios, provides troubleshooting guidance, and suggests solutions.
The True Meaning of “–00”
According to the Schneider ATV310 user manual, “–00” means the drive is in Ready status, meaning it has powered up and completed self-diagnosis but has not yet received a valid run command. The motor remains stopped. This is the factory default standby display. Once the user issues a run command and provides a valid speed reference, the display switches to show the actual output frequency or speed.
It is important to note that after freewheel stop or fast stop, the display will also return to “–00.” Therefore, “–00” can appear both at startup and after the motor has been stopped.
Common Causes
Several reasons may cause the ATV310 to stay on “–00”:
1. No Run Command Received
By default:
- LI1 terminal is assigned as Forward run (2-wire control).
- AI1 terminal is assigned as the speed reference (0–5 V).
If LI1 is not receiving a +24 V signal or AI1 is 0 V, the drive will remain at “–00.”
2. Local Control Not Enabled
Some users want to operate directly via the keypad and knob. However, the RUN/STOP keys and knob are disabled by default. To enable local control:
- Set 401 (Reference channel 1) to 183 = Integrated keypad/knob.
- Set 407 (Command channel 1) to Local.
After these settings, the drive can be run from the keypad and adjusted via the knob, and the display will change from “–00” to show real-time frequency.
3. Freewheel or Fast Stop Interference
If a digital input is assigned to “Freewheel stop” or “Fast stop” (parameters 502.1, 502.2), the drive will stop immediately when triggered and return to “–00.” Users should check whether these inputs are wrongly assigned or permanently active.
4. Control Method Mismatch
ATV310 supports both 2-wire and 3-wire control. If parameters 201 (Control type) and 202 (2-wire control type) do not match the wiring, run commands cannot be recognized. In addition, parameter 203 (Logic type) must match the wiring scheme: PNP wiring requires positive logic, while NPN wiring requires negative logic. Otherwise, the drive may ignore the input and remain at “–00.”
5. Drive Set to Bus Control
If the command channel is set to Modbus or remote mode but no communication command is received, the drive will stay at “–00,” waiting for instructions.
Troubleshooting and Solutions
The following systematic approach helps resolve the “–00” situation:
Step 1: Confirm Display Status
- “–00”: Drive ready, motor stopped.
- “502.1”: Freewheel stop active.
- “–01”: Fast stop active.
If always “–00,” the drive has not entered run mode.
Step 2: Check Command Source
- Verify parameter 407 to see if the command source is Terminal or Local.
- If Terminal: check that LI1 is receiving +24 V.
- If Local: ensure 401 = 183 (HMI knob) and the knob is not at zero.
Step 3: Verify Speed Reference
- If using AI1, ensure correct wiring (5V–AI1–COM) and output >0 V.
- If using local knob, confirm it is enabled.
Step 4: Check Stop Functions
- Verify that 502.1 and 502.2 are not assigned or permanently active.
Step 5: Confirm Logic Type
- Parameter 203 must correspond to the wiring scheme: Positive logic for PNP, Negative logic for NPN.
Step 6: Restore Factory Defaults
- If parameters are uncertain, restore defaults with 102 = 64, then reconfigure.
Practical Case Studies
Case 1: Missing Terminal Command
A technician found that a new ATV310 remained at “–00.” Investigation showed LI1 was not connected to +24 V. Once wired correctly, the drive ran normally.
Case 2: Knob Not Working
A user tried to run the drive via the knob but it stayed on “–00.” Parameters showed 401 still set to AI1 and 407 set to Terminal. After switching to Local, knob control worked.
Case 3: Stop Function Triggered
In one case, the drive stopped by itself after a short run and returned to “–00.” It was found that a faulty switch connected to the Freewheel stop input was randomly activating. Replacing the switch solved the issue.
Preventive Measures and Recommendations
- Plan wiring before installation: Ensure parameters match wiring scheme (2-wire/3-wire, Local/Remote).
- Test with Local mode first: Use keypad/knob to confirm basic functionality before enabling terminal control.
- Avoid unnecessary stop inputs: Do not keep Freewheel/Fast stop terminals permanently active.
- Routine checks: Inspect wiring and potentiometer regularly to avoid false “–00” conditions.
- Parameter backup: Save critical parameter settings after commissioning for easy recovery.
Conclusion
The “–00” display on Schneider ATV310 drives is not an error but indicates the drive is ready while the motor is stopped. Common causes include missing run commands, zero speed reference, disabled local control, stop functions triggered, or logic mismatches. By following structured troubleshooting and aligning parameters with wiring, users can resolve this issue quickly. Correct configuration ensures reliable drive operation, prevents misinterpretation as faults, and enhances system stability and efficiency.