20080128_2154.pdf

DECISION MEMORANDUM
TO:COMMISSIONER REDFORD
COMMISSIONER SMITH
CO MMISSI 0 NER KEMPTON
COMMISSION SECRETARY
LEGAL
WORKING FILE
FROM:GERRY GALINATO
DATE:JANUARY 25, 2008
RE:TARIFF I.c. NO., ELECTRIC SERVICE REGULATION 5;
ROCKY MOUNTAIN TARIFF ADVICE NO. 07-11.
BACKGROUND
On December 4 2007, Rocky Mountain Power (Rocky Mountain; Company), a Division
ofPaciforp, submitted some proposed changes to its Tariff No. 1 for electric service in Idaho.
Specifically, the Company requested revisions of Sheet No.R.2 , Regulation 5, to add a
provision addressing the customers ' responsibility to control harmonic distortion from their
equipment that back feeds onto the grid. The Company is experiencing increased use of variable
frequency drives in farming, commercial and industrial applications. The Company indicated
that this equipment could create harmonics that, if not filtered by the customer, travel back onto
the electrical grid and may cause problems for other customers.
The Institute of Electrical and Electronics Engineers (IEEE) has published acceptable
limits for harmonics standard (IEEE 519) which has been referenced in the Company s proposal.
In addition, the Company also proposed a housekeeping change to Rule 5 , paragraph 3.b to make
it clear that this paragraph applies to both prospective and existing customers. If approved by the
Commission, the Company plans to send letters to all irrigation customers informing them of the
revision and the importance of installing filters on their equipment to mitigate service quality
problems.
After initial review by Commission Staff and discussions with Rocky Mountain Power
the Company resubmitted a revised filing for the proposed changes to TariffI.P.C. No.1 on
January 22, 2008.
DECISION MEMORANDUM JANUARY 25 , 2008
ST AFF REVIEW
Adjustable frequency drive (AFD) also known as variable frequency drive (VFD) or
adjustable speed drive (ASD) is normally installed by agricultural, commercial or industrial
electric customers to improve efficiency and flexibility of electric motor/pump operations.
Unfortunately, while variable frequency drives offer many advantages for critical motor
speed control and optimizing energy consumption, they are also known for producing significant
levels of harmonic distortion. Harmonic distortion is a continuous or sporadic distortions of the
60-hertz voltage sine waveform usually caused by microprocessor-based loads such as variable
speed drives. Due to the nature of the electronics creating the variable frequency, harmonic
voltage distortion can result. Literature indicates that harmonic distortion could travel back to
the utility grid and could potentially create problems with utility equipment such as relays
transformers and other control equipment. These harmonics could also potentially cause
problems with other customers. On customers ' facilities, harmonic distortion may also create
problems with their own plant electrical systems, transformers, motors and others.
To minimize harmonic distortion in the system caused by variable speed drives, a device
called a "harmonic filter" is normally installed. Staff believes that this type of a device is readily
available in the market. There are models that are used specifically for indoor applications and
others are for outdoor applications like irrigation pumps installed in the field without building
enclosures. The outdoor type harmonic filters are more expensive than the indoor type.
In order to prevent harmonic distortion, which could potentially damage utility and other
customers' electrical equipment , Staff agrees with the Company s proposal to require its
customers who have operating equipment producing harmonic distortions to install harmonic
filters to reduce these distortions to acceptable limits.
The Commission has previously approved a similar requirement for the Idaho Power
Company Tariff No. 101 , Rule K, Customer s Load and Operations, Section 2, which states:
Section 2. Practices and Requirements for Harmonic Control.Customers
are required to comply with Practices and Requirements for Harmonic Control
in Electric Power Systems as set forth in the Institute of Electrical and Electronic
Engineers ("IEEE") Standard 519-1992. The values indicated by IEEE Standard
519-1992 apply at the point where the Company s equipment interfaces with the
Customer s equipment.
DECISION MEMORANDUM JANUARY 25 2008
Rocky Mountain initially proposed to provide filtering equipment to limit the distortion
to within limits prescribed in the Company s Electric Service Requirements as measured at the
delivery point. Staff believes that the requirement is consistent with other electric utility rules in
Idaho, but should be more specifically cited as IEEE Standard 519-1992 in Section 2.of the
Tariff. Staff contacted the Company to make this change and the proposed addition was
included in the revised filing submitted on January 22, 2008.
Staff also agrees with the proposed housekeeping changes in Rule 5 , paragraph 3.5. This
change will make it clear that this paragraph applies to both prospective and existing customers.
Staff notes that requiring the Company s current customers, particularly the irrigation
customers, to install harmonic filters will be an additional burden to their operation costs, which
may affect the economics of operating the variable frequency drives. Similarly, the payback on
the installation of VFDs as energy conservation and cost reduction measures may be negatively
affected by installing harmonic filters. This additional cost could then reduce installation of
VFDs in the field, thereby increasing electric energy consumption. According to the Company,
there are approximately 100 adjustable speed devices installed in its service territory. The
Company indicated that the average cost of installing filters is approximately $5 000. Staffs
independent inquiry from vendors indicates that the cost of installing harmonic filters range from
$10 to $13/hp. It would be beneficial if the Company could provide some help through its
existing DSM incentive programs or refer their customers to other resources that could lower the
cost of installing filters. The Company has indicated that it intends to send a letter to all
irrigators about this matter, and based on Staffs recommendation, has agreed to include the
following information. The Idaho Office of Energy Resources ' Low Interest Loan Program
(208-334-SA VE, Boise) or the USDA Farm Bill Section 9006 Energy Efficiency and Renewable
Energy Grant Program (208-785-5840 Ext. 118 , Blackfoot) may have some financial incentives
available to help finance packaged VFD and harmonic filter systems for new installations.
RECOMMENDATIONS:
1. Staff recommends that the Commission approve the requested revisions of Rocky
Mountain Power to Rule 5 , Section 2 addressing its customers ' responsibility to control
harmonics fed onto the grid from their equipment.
DECISION MEMORANDUM JANUARY 25, 2008
2. Staff recommends that the Commission approve the housekeeping change to Rule 5
paragraph 3.b. as proposed by Rocky Mountain Power.
3. If the Commission approves the proposed changes, Rocky Mountain Power suggests and
Staff recommends that the revised Tariff pages become effective on February 1 , 2008.
COMMISSION DECISIONS
Does the Commission wish to approve the proposed revisions to Rocky Mountain Power
TariffI.P.u.c. No.Regulation 57 Ifso, should the effective date be February 20087
Does the Commission wish to address anyth~ else7
Attachments
i:udmemos/RMC Advice No. 07-
DECISION MEMORANDUM JANUARY 25 , 2008
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~OUNT AIN
201 South Main , Suite 2300
Salt Lake City, Utah 84111
January 22, 2008
VL4 ELECTRONIC FILING
Idaho Public Utilities Commission
472 West Washington
Boise, Id 83702-5983
Attention:Jean D. Jewell
Commission Secretary
Re:Advice No. 07-
Regulation 5 - Customer s Installation
Rocky Mountain Power, a division of PacifiCorp, hereby re-submits for electronic filing revised
proposed tariff pages associated with Tariff LP.C. No.1 of Rocky Mountain Power applicable
to electric service in the State of Idaho. The Company respectfully requests an effective date of
February 1 , 2008.
First Revision of Sheet No. 5.R.2
First Revision of Sheet No. 5.R.3
Regulation 5
Regulation 5
Customer s Installation
Customer s Installation
The Company originally submitted proposed changes to Regulation 5 on December 4, 2007, to
address customers' responsibility to control harmonics fed onto the grid from their equipment.
This equipment can create harmonics that, if not filtered by the customer, travel back onto the
electrical grid and may cause problems for other customers. After subsequent discussions with
the Commission staff, the Company agreed to provide a revised version of Rule 5, directly citing
in Section 2 the Institute of Electrical and Electronics Engineers (IEEE) Standard 519 to which
customers are proposed to be held.
It is respectfully requested that all formal correspondence and staff requests regarding this matter
be addressed to one or more of the following:
By E-mail (preferred):datareq uest(fYpac ificorp. com
By fax:[phone]
By regular mail:Data Request Response CenterPacifiCorp
825 NE Multnomah, Suite 2000
Portland, OR 97232
Idaho Public Utilities Commission
January 22, 2008
Page 2
Informal inquiries may be directed to Brian Dickman, Idaho regulatory affairs manager, at (801)
220-4975.
Very truly yours
,- E-' tf. '::) 'k -l C'-':S c-..
jp~
Jeffrey K. Larsen
Vice President, Regulation
Enclosures
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~OUNTAIN
C. No.
First Revision of Sheet No. 5R.2
Cancelin Original Sheet No. 5R.2
SERVICE ENTRANCES AND CONNECTIONS (continued)(c) Clearances
Whenever the initial clearances of serving facilities over Customer s premises, required by
applicable laws, ordinances, rules, or regulations of public authorities, become inadequate
due to changes made by the Customer, the Customer shall be responsible for correction of
the deficiency.
CUSTOMER'S LOAD AND OPERATION(a) Protection of Customer s Equipment
The Customer shall furnish, install , inspect and keep in good and safe condition all
electrical wires and lines on Customer s premises. The Customer shall provide devices to
protect his equipment from high and low voltage, from overload, single phasing or other
abnonnal conditions.
(b)Protection of Company s Equipment and other Customers
The Customer shall provide control equipment to eliminate excessive starting current or
undesirable voltage fluctuations on the Company s circuits. If the Customer makes
additions or changes in his electrical facilities, either in size or character, the Customer shall
give the Company prior written notice of this fact. Any such additions or changes in load
shall not be detrimental to service to other Customers.
Practices and Requirements for Harmonic Control
Customers who have equipment that produces harmonic distortion shall provide filtering
equipment to limit that distOltion to within limits prescribed in the Institute of Electrical and
Electronics Engineers (IEEE) Standard 519 as measured at the Point of Delivery.
( e!!)Customer s Generation
Customer shall sign a written agreement with the Company prior to connecting to and using
another source of power in conjunction with receiving service from Company. The
Customer shall supply all equipment, including but not limited to, transfer switches
disconnects, overload protection, and any other protective devices necessary to safely
connect to and operate from another power source. Emergency generators must be
equipped and operated to prevent connection with Company s system. The Customer shall
be liable for any damage or injury resulting from using another power source.
(4!i)Maintenance of Customer s Facilities
Installation and maintenance of all facilities beyond the point of delivery, except Company
owned metering equipment, shall be at the expense and responsibility of the Customer
except under conditions specified by the Company in writing.
(Continued)
I Submitted Under Advice Letter No. %07 %11
I ISSUED: August 11 , 2006January 22.2008 EFFECTIVE: September 15February 1. 2008
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~OUNT AIN
LP.C. No.
First Revision of Sheet No. 5R.3
Cancelin Original Sheet No. 5R.3
CUSTOMER'S LOAD AND OPERATION (continued)(e!) Highly Fluctuating Loads
If a Customer uses welding machines, X-ray apparatus, elevators or other equipment with
highly fluctuating load characteristics, or having an abnormal effect on voltage, and whose
operation requires the Company to install transformer capacity or other equipment in order
to protect the quaIity of service to other Customers or to provide for short period use
power by such equipment, the Company will provide service as described in Regulation 12.
The Company reserves the right to refuse to supply service to loads of a character which
may seriously impair service to any Customer and shall have the right to discontinue service
to the Customer who shall continue to use appliances or apparatus detrimental to the service
to any customer after being notified thereof in writing by the Company.
REFUSAL OF SERVICE
The Company may disconnect service or refuse to connect or supply service:
(a)when the Customer s wiring or facilities are in Company s judgment unsafe or hazardous to
the Customer or others or found to be in violation of applicable laws, ordinances, rules or
regulations.
(b)where such connection or service will adversely affect or impair or is adversely affecting or
impairing the service to its other Customers.
(c)where the Applicant or Customer has not compIied with federal, state, municipal or
Company regulations.
(d)until the Customer is advised by proper authority that the wiring and utilization equipment
to be served have been inspected and passed by the controlling public inspection authority, ,
where inspection is required by 10caI ordinance or other authorized procedures. Any
affidavits or certificates of inspection required by law must be furnished before service is
connected.
COMP ANY LIABILITY
The Company s liability shall cease at the ft30int of Q.aelivery. The use of electric service beyond
said point is at the risk and responsibility of the Customer.
(Continued)
I Submitted Under Advice Letter No. G6-%O7-
I ISSUED: i\ugust 11, 2006January 22,2008 EFFECTIVE: September IS, 2006February I, 2008
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aUNT AIN
c. No.
First Revision of Sheet No. SR.2
Canceling Original Sheet No. SR.2
SERVICE ENTRANCES AND CONNECTIONS (continued)(c) Clearances
Whenever the initial clearances of serving facilities over Customer s premises, required by
applicable laws, ordinances, rules, or regulations of public authorities, become inadequate
due to changes made by the Customer, the Customer shall be responsible for correction of
the deficiency.
CUSTOMER'S LOAD AND OPERATION(a) Protection of Customer s Equipment
The Customer shall furnish, install, inspect and keep in good and safe condition all
electrical wires and lines on Customer s premises. The Customer shall provide devices to
protect his equipment from high and low voltage, from overload, single phasing or other
abnonnal conditions.
(b)Protection of Company s Equipment and other Customers
The Customer shall provide control equipment to eliminate excessive starting current or
undesirable voltage fluctuations on the Company s Circuits. If the Customer makes
additions or changes in his electrical facilities, either in size or character, the Customer shall
give the Company prior written notice of this fact. Any such additions or changes in load
shall not be detrimental to service to other Customers.
(c)Practices and Requirements for Harmonic Control
Customers who have equipment that produces hannonic distortion shall provide filtering
equipment to limit that distortion to within limits prescribed in the Institute of Electrical and
Electronics Engineers (IEEE) Standard 519 as measured at the Point of Delivery.
(d)Customer s Generation
Customer shall sign a written agreement with the Company prior to connecting to and using
another source of power in conjunction with receiving service from Company, The
Customer shall supply all equipment, including but not limited to, transfer switches
disconnects, overload protection, and any other protective devices necessary to safely
connect to and operate from another power source. Emergency generators must be
equipped and operated to prevent connection with Company s system. The Customer shall
be Iiable for any damage or injury resulting from using another power source.
(e)Maintenance of Customer s Facilities
Installation and maintenance of all facilities beyond the point of delivery, except Company
owned metering equipment, shall be at the expense and responsibility of the Customer
except under conditions specified by the Company in writing.
(Continued)
Submitted Under Advice Letter No. 07-
EFFECTIVE: February 1 2008ISSUED: January 22, 2008