Hi Troy,
Will you please provide a quote to move forward with the following:
(1) create a hardwired interconnect diagrams to connect the VFD’s directly to PLC I/O
(2) work with GPEC to install the wiring and modify the VFD and PLC programming to accommodate for the change.
Jason is working hard to keep the TPS running, we would like to expedite this as soon as possible.
Regards,
Jennifer Cline, P.E.
City of Molalla
Public Works Director
O: 503.759.0218
F: 503.829.3676
"From: Troy Collison [mailto:tbc@industrialsystems-inc.com]
Sent: Wednesday, June 17, 2015 10:20 AM
To: Jason Clifford
Cc: Jennifer Cline; John Sowards; Mark Lietzke
Subject: Molalla WWTP - VFD communications
Hi Jason,
As discussed on Monday, I wanted to take a few minutes to outline a recurring problem with the VFD’s that operate both the transfer pumps and the effluent pumps at your facility.
All three transfer pumps and both effluent pumps use fuji variable speed drives (VFD’s) that are relabeled as a GE product.
These drives are controlled by the PLC system via GE’s GENIUS communications protocol using a 3rd party communications module manufactured by Horner Electric.
We first started noting the VFD’s faulting due to a problem with the options module (the Horner communication module) several months ago. Mark Lietzke from our office had mentioned to the operators at the WWTP at that time, that an alternative way of controlling the VFD’s may need be implemented but the problem appeared to go away so nothing was done.
The issue has returned however and appears to be here to stay.
We would normally just install a new communication module in a case like this however GE has abandoned the GENIUS protocol and the modules by Horner are no longer available.
We can attempt to locate 2nd hand or secondary market modules if you like us to.
Or, we can crate hardwired interconnect diagrams to connect the VFD’s directly to PLC I/O and then work with your electrician to install the wiring and modify the VFD and PLC programming to accommodate this change.
A third option would be to replace the VFD’s but that will be very expensive and should be discussed internally and budgeted for well in advance.
I would like to know if you agree with our preferred approach to this problem of moving the VFD control off Genius and to hardwired connections. If so, we will prepare the needed schematics and work on the programming while guiding your electrician to install the needed wiring.
Please let us know how you would like to proceed.
Thanks!
Troy B. Collison
5835 NE 122nd Avenue, Suite #110
Portland, Oregon 97230
http://www.industrialsystems-inc.com
Phone: 503.262.0367
Cell: 360.957.5039
Fax: 503.262.0371
CCB # 196597 WA #INDUSSI880K9
AK# 1018436