Danfoss mcd-500 Operating Instruction

Also see for vlt soft starter mcd 500: Installation instructions Installation instructions Installation instructions Installation guide Installation guide

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Danfoss mcd-500 Operating Instruction Manual pdf 83 page image

9 TroubleshootingWhen a protection condition is detected, the MCD 500 will write this to the event log and may also trip or issue a warning. The soft starter's response tosome protections may depend on the Protection Action settings (parameter group 16).If the MCD 500 trips you will need to reset the soft starter before restarting. If the MCD 500 has issued a warning, the soft starter will reset itself oncethe cause of the warning has been resolved.Some protections cause a fatal trip. This response is pre-defined and cannot be overridden. These protection mechanisms are designed to protect thesoft starter, or can be caused by a fault within the soft starter.9.2 Trip MessagesThis table lists soft starter's protection mechanisms and the probable cause of the trip. Some of these can be adjusted using parameter group 2Protection and parameter group 16Protection Action, other settings are built-in system protections and cannot be set or adjusted.Display Possible cause/Suggested solutionBattery/Clock A verification error has occurred on the real time clock, or the backup battery voltage is low. If the batteryis low and the power is off, date/time settings will be lost. Reprogram the date and time.Related Pars.: 16-12Current Imbalance Current imbalance can be caused by problems with the motor, the environment or the installation, suchas:- An imbalance in the incoming mains voltage- A problem with the motor windings- A light load on the motorCurrent imbalance can also be caused by incorrect cabling between the external bypass contactor and thesoft starter or an internal problem with the soft starter, particularly an SCR that has failed open circuit. Afailed SCR can only be definitely diagnosed by replacing the SCR and checking the starter's performance.Related Pars.: 2-2, 2-3, 16-2Excess Start Time Excess start time trip can occur in the following conditions:- The FLC setting is wrong- The Current Limit has been set too low- The Start Ramp Time has been set greater than the Excess Start Time settingThe Start Ramp Time is set too short for a high inertia load when using adaptive acceleration controlRelated Pars.: 1-1, 1-6, 1-4, 1-9, 7-9, 7-1, 7-6, 7-4, 16-7FLC Too High The MCD 500 can support higher motor FLC values when connected to the motor using inside delta con-figuration rather than in-line connection. If the soft starter is connected in-line but the selected motor FLCis above the in-line maximum, the soft starter will trip at start.Related Pars.: 1-1, 7-1Frequency The mains frequency has gone beyond the specified range.Check for other equipment in the area that could be affecting the mains supply (particularly variable speeddrives).If the MCD 500 is connected to a generator set supply, the generator may be too small or could have aspeed regulation problem.Related Pars.: 2-8, 2-9, 2-10, 16-5MCD 500 Operating Instruction 9 TroubleshootingMG.17.K2.02 - VLT® is a registered Danfoss trademark 839