- July 16, 2012
- Posted by: designer
- Categories: Articles, Hot topics, Industrial News, portfolio
Our client had a new 138kV transmission line and autotransformer being added to an existing
station arranged in a breaker & ½ scheme. They needed line relaying (SEL 311L/421 protection
with 451 reclosing and breaker control) to replace an existing line panel. Another two panels were
added with 311L/311L & 451 relays for redundant hot-standby 87L/DCB protection of the new
138kV line and autotransformer. All three of the new and existing panels were wired into the
existing high-Z bus differential scheme.
The panels were bid out to Panel Vendors (PV), including the Engineering (relay specification,
panel layout, schematics, wiring diagrams), Relay Settings and Final Commissioning. Upon receipt
of the specifications Keystone Electrical Manufacturing, Co, (2511 Bell Avenue Des Moines, IA
50321) requested assistance by A2V Partners LLC (A2V) for the engineering required. A2V
worked as a subcontractor to Keystone.
As we do with all of our projects, we consulted with the owner to be sure we understood the needs
and the specific installation situation. The owner had a panel layout included in the specification so
we did not need to provide it (we easily could have if needed). A2V then specified the exact relay
models to be used and these where ordered by Keystone for installation in the panels to be
A2V then developed schematics, including discussion/review by owner for specific preferences.
Next A2V developed wiring diagrams per the schematics and emailed to Keystone for fabrication
and point to point checkout.
A2V received the client’s ASPEN System model and using the model we developed the protection
set points needed.
A2V incorporated schematics, operation preferences and needed relay logic into individual final
relay settings. We then developed the relay logic drawing. These diagram all relay I/O and
operation functions on one drawing for clear operation checkout and final record.
A2V attended the pre-construction meeting on site, and made two trips back for final relay
connections and commissioning of the two lines.
This was a very successful project for A2V, for the PV and for the client. Tidal Power Services was
the testing company our client used. They were top notch in our opinion. The commissioning and
relay testing went very smoothly and we look forward to working with them in the future! Oh and
did I mention that all of the schedules were met and the client was very complimentary.
We are a small, but growing company. We strive to always add a high level of value for our clients
and if we make a commitment we intend to keep it! We would be glad to give you more specific
information and specific references. If you have a project that you would like to have turn out as
well as this one did, you should give us a call.
E. Matt Bedinghaus, PE
CEO & Chief Engineer