The most commonly heard comment about condition monitoring of Materials Handling equipment is that “it can’t be done”. But with know-how correctly applied, it not only can be – it has been.
Materials handling equipment is used mostly for short duration, repetitive operations, with shock loads. All of which, many people believe, make it impossible to take meaningful vibration or thermographic readings. But that’s simply not true.
All it requires is the knowledge and experience to identify what and where to monitor. The understanding and insight to decide the correct parameters to monitor. And the expertise to extrapolate the data, to provide useful results.
The Bigger Picture
ERIKS faced this kind of challenge when a customer needed to identify the cause of failure on part of a large, PLC-controlled, materials handling system.
The section in question operated only for a few seconds at a time, with repeated variable shock loads. So traditional vibration monitoring of the section wouldn’t work. But that didn’t mean data couldn’t be gathered. The solution was to monitor not just the required section, but the whole system.
Data from the PLC could then be used to identify where within the system each vibration event occurred. By programming the PLC with the required vibration parameters, and setting it up to create a time stamp whenever they were exceeded, it was possible to cross-reference the time with the positioning data, to identify exactly where within the system the problems were arising.
It’s another common misconception that temperature monitoring isn’t possible for equipment that operates intermittently, for short periods. But again, know-how makes it possible.
The solution is to monitor the control panel, where changes in cable temperatures can be detected even after just a few minutes’ operation. It’s then a case of interpreting and extrapolating the data, based on experience, to detect any issues.
For example, an ERIKS customer was experiencing repeated failures of small motors used for materials handling operations, and couldn’t find out why.
ERIKS carried out thermographic monitoring of the control panel, which revealed a change in temperature in a cable. Experience suggested this could be an indication of a poor connection – which proved to be correct. And this poor connection had been causing intermittent severe voltage drop, which in turn caused the motor failures. Once the root cause was detected and the connection repaired, the failures stopped.
So it’s true that condition monitoring of materials handling equipment is difficult. But it’s certainly not impossible. All it needs is an understanding of how and why machines fail, applied to deciding what, where and how to monitor machine condition.
They say it can’t be done. ERIKS says it can.