Why is my inverter drawing too much current?

At IDS we receive a lot of technical enquiries regarding inverters. Over the last few months we have addressed a wide variety of these in article form, hoping to give our readers a valuable resource to consult as and when required. The topic of these FAQ articles range from How To Run An Inverter On A Generator to How To Store Inverters in this article we take a look at another frequently asked question: Why is my inverter drawing too much current?

Why is my inverter drawing too much current?

Sometimes inverters draw too much current. They protect themselves by tripping on ‘overcurrent’ or ‘short circuit’, but what are the causes?

Here are some possible reasons and advice to mitigate what you are experiencing:

Motor / inverter package is underpowered for the load. This is a design fault and equipment upgrade is the most likely solution.
Too fast a ramp time for high inertia loads – if the load has a high inertia then it will take time to get it rotating. Extend the ramp time and try again.
Wrong data in Group 99. This is where the motor data is stored. If it is incorrect or an ID Run was not performed correctly then the inverter is likely to react in an erratic manner including too high a current. Check the data against the motor’s nameplate and use it exactly (e.g. do not use 1500rpm if the nameplate says 1475rpm!) and carry out another ID run. A ‘motor only’ rotating ID run gives the best results even though a static one usually suffices.
Wrong motor connection. Check that the motor connection is suitable for the voltage applied. If connected for the wrong voltage there will always be problems. This is a common fault (choosing either star or delta connection incorrectly).

Has this fixed the problem?

All fixed? If yes, please leave us a comment below. If no, call us on 0115 944 1036 or email [email protected] one of our experienced inverter engineers will help.

If you have a recurring query you would like to see featured in these FAQ style articles please let us know, use the comment section below or the contact details above.