P
G'day
A problem occurs occasionally, where the analogue output modules lock up with dire consequences with the variable speed drives been used. The last known analogue signal will drive the vvvf at the wrong speed which causes problems with the process. There are two sample station employed identical in design and layout.
The PLC and I/O are all mounted inside the one cubicle with the vvvf Toshiba drives as well as microwave detector evaluation boxes and other
equipment mounted in the vicinity. The DOL drives are mounted in a adjacent panel serrated by the stainless wall of the cubicle. The PLC is supplied by a separate UPS supply from a substation @ 100 metres away separate to any other supply used in this MCC. Simple things like a brown out or lighting faults in the area appear to cause the problem of the analogs locking up.
From what I have read, the system bonding and grounding could be the source of the problem. As well as the segration of cabling in the PLC panel is non existent. If anyone may have encountered similar problem or can throw some light on this problem it would be appreciated.
Regards
Phil Dryburgh
A problem occurs occasionally, where the analogue output modules lock up with dire consequences with the variable speed drives been used. The last known analogue signal will drive the vvvf at the wrong speed which causes problems with the process. There are two sample station employed identical in design and layout.
The PLC and I/O are all mounted inside the one cubicle with the vvvf Toshiba drives as well as microwave detector evaluation boxes and other
equipment mounted in the vicinity. The DOL drives are mounted in a adjacent panel serrated by the stainless wall of the cubicle. The PLC is supplied by a separate UPS supply from a substation @ 100 metres away separate to any other supply used in this MCC. Simple things like a brown out or lighting faults in the area appear to cause the problem of the analogs locking up.
From what I have read, the system bonding and grounding could be the source of the problem. As well as the segration of cabling in the PLC panel is non existent. If anyone may have encountered similar problem or can throw some light on this problem it would be appreciated.
Regards
Phil Dryburgh