NS Central Surrey

NS Central Surrey Project Completed

There was a lot of prep work for this project to get to the point of shutting down on a Friday night, and working around the clock with four electricians and two helpers, for a Monday morning testing.

We spent about 2 1/2 days going over everything in the field and the program with the engineer to get the plant to start up again in mid-week. We tried to keep the downtime to a minimum by working around the clock on the weekend to do the change over.

The following eight pictures are of the main PLC upgrade which consisted of two racks with one processor and two communication cards for the two rack to communicate together.

The balance of the cards are for input, output and analog cards. These broke down to various types of those cards also.

There is also a sixnet ethernet switch in this cabinet and in the new RIO cabinet in the field for communications.

The lower Rack also has a modbus plus card there that is tied to two additional PLC’s within the plant.

We changed the two output cards so that they would fire isolating relays which in turn would turn on the field device. An extra measure of precaution.


In the next group of photos, we show a power cabinet by the RIO(remote inputs / outputs ) cabinet. This small cabinet houses a surge protection relay as well as a UPS for power to the RIO PLC panel.

For this RIO cabinet we had a 1/4 inch steel plate wall built with a roof. We then had a cut out into the building above the RIO panel and mounted cable tray above and beside the new panels.

The RIO panel was built so we could enter the cables from the bottom of the cabinet or the top if needed but with preference to the bottom entry on this outside panel.

This New RIO rack now offers the availability of wiring the field devices from the tank farm and pump house to this new rack without going all the way back to the main building.

We have allowed for a 2nd plc to be installed at this RIO location if needed in the future. So expansion is relatively easy for any thing in the future.

We have wired in two input cards and two analog cards to begin with on this cabinet with more to follow in the future.