I've been asked to troubleshoot an issue with a motor controller built around a Leeson Speedmaster SM Plus Series Sub-Micro Inverter.
I realise that this should perhaps be in Off Topic instead of General Electronics, but as Off Topic can only be viewed by members (and therefore no Off Topic threads are scraped by Google et al) it would be better here for the benefit of others in the future.
Is there anyone here who has experience with this or a similar VFD?
The issue is that occasionally, the unit either:
- fails to drive the attached motor upon command, or
- begins to drive the motor upon command, but then ceases after a random interval ranging from a few seconds to a few dozen seconds.
The drive is operating with speed control via an external voltage, provided by a potentiometer.
When these failures occur, the code 'UF' is show on the display. The fault seems to clear when a stop command is issued, after an interval of several seconds.
I've read the relevant parts of the manual and quick start guide, and I'm left with the impression that the associated 'START FAULT' tied to the 'UF' display code should not occur while the drive is in operation, but only when power is applied to the unit.
A review of the most recent fault codes using Parameter 50 (fault history) does >>not<< show UF among the recent codes. However, I expect this is normal...? The codes which >>are<< listed are 'LF', for 'Low DC Bus Voltage Fault', and F9, which suggests 'Internal Faults: The control board has sensed a problem - consult factory.'
I've sent an email to the local distributor, and they've forwarded it on to their 'tech team', but I don't expect an answer soon.
This is of a somewhat time sensitive nature, as the drive/motor is used to operate a revolve in a stage production which is opening very soon... actually, 30 minutes ago... so they're swinging without a net at the moment!