Page 12 - Q2_2020_Newsletter

One crucial factor to remember when working on Mission critical
Substation with Utility Transfer Switchgear that was supplying the site. It is' common for most of Rosendin's Mission Critical
campuses to have multiple utility feeds from more than one utility source, so in the event one goes out, there is a backup
through the Utility Transfer Switchgear (see picture above).
The Utility Transfer Switchgear has automatic switching executed through a sophisticated series of controls and relays to
activate all alternate sources of power during a utility outage, and back to utility sources when the power is restored.
Another factor in this type of design is the importance of phase sequence and phase rotation that matches, from all
potential sources, to keep the end equipment critical load in operation. If sources are not in phase, certain equipment will
not function, or operations of some equipment would make the unit run backwards which could be catastrophic to some
operations. As electricians, we must conduct these verifications. Rosendin also has a training program for test tools that
goes deep into utilization and safety factors.
The images below are of a utility site distribution one-lines. Training attendees will acquire useful knowledge about the
types of utility switching equipment while utilizing the legend page "Identify Specific Equipment." This will also introduce
attendees to back feeds with this simple one-line as they follow the electrical flow.
There is a safety factor and a communication importance factor when dealing
with similar nomenclature. After the utility one-line, I work the attendees
through the next set of plans.
12 The Feeder | Issue 2, 2020
sites is how closely electrical equipment is labeled (see example
on right). The figure illustrates that the last letter is the only
difference from the "A-Side" and the "B-Side"." There are safety
and communication importance factors when dealing with similar
nomenclature. After the utility one-line, the attendees work through
the next set of plans.
The images below are of several Main Switch Boards on a one-line
drawing that has the possibility of being backfed from multiple
alternative energy sources (up to 11 back feeds). The first question
attendees are asked is, "What is the primary source of power to this
MSB?" The utility one-line drawings shown previously identifies which MSB's they are feeding. Attendees then make their
way through the equipment identifying the primary second source of power (generator). From there we talk about the
equipment itself: voltage, amperage rating, KAIC rating, and its impact, if not followed correctly with smaller KAIC sized
breakers being installed. Discussion then flows into OCPD's and what AT and A.F. mean around the OCPD's symbol. I ask a
couple of questions about feeder "call-outs" which makes attendees refer to the feeder schedule and its information and is
also an opportunity to talk about drawing revisions and how engineers and architects identify them. Given the complexity
of the electrical system, we review the entire one-line, identifying the possible sources for every piece of equipment by
giving attendees a series of questions. One of the first is about the 4000amp breakers and how they have an "N.O." or
"N.C." and how they are fed from multiple sources.
The image above shows the utility site and the medium voltage path to the site's Main Switch Boards. There are multiple
feeds, and the site utilizes a "Tie-Breaker" for redundancy which is the first exposure in the training that shows redundant
feeds. This has a huge impact moving forward because all the MSB's have redundant power present in the Main Switch
Board(s) once the "swing" Main Switch Board is energized.
The training also covers how construction schedules have changed and are now more compressed than ever before. Being
a company built on continuous improvement, attendees are introduced to the "Plan-Do-Check-Act," a Lean Construction
concept.
During the training associated with the image above, the following topics and questions are asked.
• What is this? Outdoor Generator Enclosure
• What voltage is the generator producing to serve the system? 480vac
• What size is the generator? 3000KW
• Where is the LOTO location(s) for EG8H? Multiply feeds would need to be locked out.
• Where is the power source to EB8H? What size raceway and conductors are necessary for this Generator Enclosure
power? What is that power sources used for in most cases?
In summary, the training conducted on the one-line drawings has helped job site professionals become aware of the
potential hazards involved with electrical work. It has ensured that affected employees on job sites have a greater
understanding of the control of hazardous energy and how to eliminate those hazards through an established LOTO
program.
Issue 2, 2020 | The Feeder 13