Error message Imax
(en) The Imax error message indicates an overcurrent on the AC side. This message usually only appears in transformer inverters and is displayed if the electric current on the AC grid is higher than specified or if there are direct current components in the grid current. Transformerless inverters are not disturbed by direct current components in the utility grid. The inverter disconnects from the utility grid for safety reasons and subsequently rechecks the connection conditions.
Notice:
In addition to the Imax error message, there is also the Imax DC error message on transformerless devices.
If the message only appears very rarely (a maximum of once or twice a week), no further action has to be taken. In this case, the next step is to continue to monitor the device.
Imax disturbances that occur over an extended period are usually caused either by direct current components in the utility grid or device defects. If the “Imax” message is displayed continuously over several days or if other transformer devices are on the same line conductor and only one device displays the “Imax” message, there is usually a defect in the device.
Corrective measures for PV system operators:
• Note the time at which the disturbance occurs and for how long it appears.
• If the disturbance recurs regularly, monitor whether there is a connection with other loads nearby, e.g. buzz saws with DC brakes (diodes), electrical welding equipment or agricultural or industrial devices in general.
• Contact your installer. The following steps require the specialist knowledge of an electrically qualified person or installer.
Corrective measures for installers:
DANGER! The tasks described below may only be performed by electrically qualified persons:
• If the fuse has blown, check the sizing and function of the fuses.
• Set the inverter to another line conductor. If this resolves the problem, check whether there are larger loads nearby. If it is not possible to reduce the size of the direct current components, it will not be possible to operate a transformer inverter on this line conductor.
If the message persists, the device must be replaced. In this case, please contact SMA Service with the following information:
• Device type and serial number of the inverter
• If the device is in the warranty period: the warranty certificate
• LED blink code and error message
• How long has the error been present for? Is it sporadic or continuous?
All work on the inverter and the cabling of the PV array must be carried out by an electrically qualified person. SMA accepts no liability for the information and solutions given in the Online Service Center. Additional information can be found in our Online Service Center’s terms and conditions of use.