Some TS4 systems may produce a high-pitched whine under certain operating conditions. This sound is not a failure and does not indicate a defect in the TS4.
What’s actually happening
The noise is caused by reverse current or short-circuit conditions. These conditions can occur when the system is operating outside steady-state conditions, such as:
- Strings are partially shaded or unevenly illuminated
- Modules in a string are operating at different voltages
- The inverter or string is regulating at low voltage or no voltage (early morning, late afternoon, cloudy conditions)
When reverse current or short circuit conditions are present, internal electronic components regulate current flow to protect the system. In some cases, this regulation can produce an audible vibration in magnetic components.
Important clarifications
- The TS4 is responding to electrical conditions created by the array or inverter operation
- The sound is temporary, harmless, and within normal operation
- No damage is occurring to the TS4, module, or inverter
- System performance and safety are not affected
When you’re most likely to hear it
- Early morning or late evening
- Rapid cloud movement
- Partial shading or mixed module orientations
- Cold ambient temperatures
- When the inverter is running an aggressive MPPT or IV curve scan
When to be concerned
If the noise is accompanied by production loss, recurring device faults, offline TS4s, or visible wiring or connector damage, follow standard troubleshooting procedures. Noise alone is not a fault condition.
Key Takeaway
The TS4 is operating as designed and responding to non-uniform electrical conditions in the system. Once the array returns to uniform operation, the sound will disappear.
Click Here to contact the Tigo Customer Success team if you have any questions.