20191018Decision Memo.pdf

DECISION MEMORANDUM
TO:COMMISSIONER KIELLANDER
COMMISSIONER RAPER
COMMISSIONER ANDERSON
COMMISSION SECRETARY
COMMISSION STAFF
LEGAL
FROM:DAYN HARDIE
DEPUTY ATTORNEY GENERAL
DATE: OCTOBER 18,2019
SUBJECT:APPLICATION OF ROCKY MOUNTAIN POWER FOR AUTHORITY TO
REVISE ELECTRIC SERVICE REGULATION NO. 6 - COMPANY'S
INSTALLATION; CASE NO. PAC-E.-19-12.
On September 13, 2019, Rocky Mountain Power ("Company") filed an Application
requesting authority to revise paragraph I of Electric Service Regulation No. 6 - Company's
Installation to include a new option for customers to receive single phase 24Ol48O volt secondary
service. The Company requests its Application be processed by Modified Procedure.
THE APPLICATION
The Company's Application is in response to limited three phase service distribution
in its service territory.I The Company states that the proposed changes in Electric Service
Regulation No. 6 will provide significant advantages to customers who are currently limited by
their single phase, 1201240 volt service. According to the Company's Application, in the absence
of three phase supply, inigation pumps, and other industries employing large motors, have
restricted commercial availability,2 However, where capacity is available on existing single phase
lines, a three phase supply can be derived from a variable frequency drive or rotary phase converter
to provide 240/480 volt service to customers. The Company states that on average 480 volt class
phase converters and motors are lOVo to 25Vo less expensive to operate than 24O volt converters.
Accommodating single phase 2401480 volt service will have very little impact on the Company's
current construction standards, practices, and inventory requirements according to the Application.
I The Company esrimates that 40 percent of its distribution lines are single phase 120/240 volt.
2 The cost to extend three phase service to these customers is prohibitive. The Company estimates that to extended three phase
primary lines would cost between $60,000 and $150,000 per mile.
Providing single phase 24Ol48O volt service, where available, will benefit customers using large
motors, transportation agencies tasked with lighting roadways, and fast charging stations for
electric vehicles while having minimal impact to the Company's operations or costs.
STAFF RECOMMENDATION
Staff recommends the Commission issue a Notice of Application and a Notice of
Modified Procedure setting a December lO,2Ol9 public comment deadline, and a December 17,
2019 Company reply deadline.
COMMISSION DECISION
Does the Commission wish to issue a Notice of Application and Notice of Modified
Procedure with a December IO,2019 public comment deadline and a December 17,2019 reply
deadline?
Dayn
Deputy Attorney General
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