MYPV ClearSky User manual

myPV ClearSky™ User Manual 1
myPV ClearSky™ User Manual

myPV ClearSky™ User Manual 2
Welcome
This interactive manual guides new and experienced users through the myPV ClearSky
modular interconnection.
Additional support is available on our website at www.myPV.pro
You may also contact support via phone or email:
Support Line (M-F, 9am-5pm Eastern): 470-387-9011
Support Email: [email protected]
Contents
Introduction
Resources
Design Considerations
Protection Relay Settings
Receiving
Electrical Terminations
Network Integration
Pre-Energization Checks
Initial Energization
Operational Testing
Commercial Operation
Spare Parts
Torque Schedules
Troubleshooting

Introduction
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Introduction
The myPV ClearSky™ Interconnection is an innovative, efficient, and reliable product
that modularizes your interconnection, accelerates your readiness for commercial
operation, and de-risks your commissioning.
Equipment Build Standards
All myPV ClearSky equipment is built with quality and reliability as our top priority.
Built to Last
With heavy 11-gauge powder coated
steel, wide temperature industrial rated
electronics, and fully integrated in a UL
508a controls facility, the product line
conforms to the following standards:
Padmount gear conforms to
applicable ANSI, IEEE, and NEMA
standards
Constructed with UL or ETL
recognized components
Equipment Build Standards
Built to Last
Standard Features
Standard Features Included
Standard Options
Standard Options Include
2021 Product Line Modifications
myPV ClearSky - 2021 Version

Introduction
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Circuit breaker ETL listed per file
4000068
Bushings & fuses rated in padmount
gear per UL file E328700
Equipment is suitable for use in
NFPA 70, NEC compliant installation
Metering and relay control panels are
UL 508a certified and labeled
Standard Features
The myPV ClearSky Interconnection product line is designed to provide a self-contained
and modularized solution for both distribution and transmission interconnected
generation facilities operating up to 35kV with a maximum continuous current of 600A
(per MV feeder).
Standard Features Included
Revenue Grade Metering Default configurations include SEL-735 metering with
revenue grade CT and PT instrumentation. Metering make/model and brand may be
modified to alternative hardware to satisfy individual customer requirements.
(Additional standard options available below)
Protection Relaying & Reclosing All configurations of the myPV ClearSky use an
SEL-751 with specific I/O and software features to support the three (3) integrated
VFI breakers. The SEL-751 shares PTs with the meter, but has dedicated protection
class CTs for appropriate fault condition monitoring. The SEL-751 may not be
modified, however a reduct relay may be added to satisfy individual customer
requirements. (Additional standard options available below)
myPV IQ™ - Remote Operator Interface All configurations of the myPV ClearSky
products arrive with a cellular modem and browser-based HMI pre-installed. The
cellular modem is enabled with a temporary data plan to support remote access to
the metering and relay devices during initial startup and commissioning activities.
The cellular service can be disabled or re-enabled to suit both security requirements
and warranty support during the warranty period. Additionally, the myPV IQ™ -

Introduction
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Remote Operator Interface provides a browser-based dashboard for commissioning
agents and engineers to access metering and relay telemetry, as well as relay event
information quickly and early without the need for any special software or skillset.
This feature does not interfere with any third-party monitoring or SCADA and may
be disabled (or upgraded) by the customer at any time.
Networking Communications All configurations of the myPV ClearSky are
equipped with an unmanaged 8-Port 10/100BaseT(X) Fast Ethernet switch. All
equipment mentioned above is connected to and IP addressed for networking
communication through this switch by default. (Additional standard options available
below)
Self-Powered & Battery Backed-Up All controls, networking, metering, and
relaying equipment run on a self-contained 24V, 20A power supply that includes
battery backup. In the event of loss-of-grid, the system remains fully operational to
provide telemetry, trip event information and alarming.
IEEE 386 MV Interfaces All configurations of the myPV ClearSky use industry
standard bushing well and inserts MV interfaces. 200A load-break or 600A dead-
break interfaces may be specified at the time of ordering based on facility amperage
requirements. (Additional standard options available below)
Standard Options
The myPV ClearSky Interconnection product line provides standard options to upgrade
and add components in a manner that supports the most frequently requested customer
requests.
Standard Options Include
Revenue Grade Metering Upgrades
[DEFAULT] Basic PQ waveform recording (15th harmonic, 16 samples/cycle, 15 cycle
duration)
[UPGRADE] Advanced PQ waveform recording (63rd harmonic, 16/128/256
sample/cycle, 15-600 cycle duration)
Protection Relay Upgrades

Introduction
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[DEFAULT] Directional Current Sensing, Reclosing, and DNP3 Communications are all
standard features
[UPGRADE] Arc Flash Sensing w/ highspeed I/O for fast tripping & Integrated fiber optic
arc flash detection
[UPGRADE] Generator-side voltage sensing for MicroGrid Vsync capabilities (Arc Flash
Sensing included)
MV Interface Dual Bushings
[DEFAULT] Three (3) MV Interfaces on the Utility side dead front, and three (3) MV
Interfaces on the Solar side dead front
[OPTION] A total of six (6) MV Interfaces on the Utility side dead front, to allow for loop-
feed or passthrough connections
[OPTION] A total of six (6) MV Interfaces on the Solar side dead front, to allow for loop-
feed or passthrough connections
Equipment Riser
[DEFAULT] Standard integrated 7” riser
[OPTION] *Taller 12” riser (Adds an additional 5” of height for MV cable management)
Solar-Side 3-Pole Ganged Load-Break Disconnect
[DEFAULT] Not included[OPTION] **Manually operated. 600A load-break, 3-pole
ganged disconnect (to isolate the myPV ClearSky™ fro the facility)
Control Cabinet
[DEFAULT] Technician visible wire-glass control cabinet door with external LOTO
handle
[OPTION] Privacy solid metal door control cabinet with external LOTO handle
[OPTION] Additional Customer equipment control cabinet with external LOTO handle
(wire-glass or solid door)
Padmount Powder Coat
[DEFAULT] Solar Industry White[OPTION] Any color you want ... as long as its white ;-)
Network Communications

Introduction
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[DEFAULT] Unmanaged 8-Port 10/100BaseT(X) Fast Ethernet switch
[MULTIPLE OPTIONS] Managed switched, MM and SM Fiber, Serial to Fiber options
are all available. Contact Us for specifics
myPV IQ™ - Remote Interface
[DEFAULT] Installed and licensed for monitoring and control of the myPV ClearSky’s
integrated metering and relaying devices
[OPTION] Upgrade the myPV IQ license to support full facility device (inverters,
trackers, weather stations, other) monitoring and control as the primary SCADA system.
Utility DER Interface
[DEFAULT] Not included
[OPTION] Additional SEL RTAC 3505 installed inside myPV ClearSky control cabinet to
support facility-to-offtaker RTU communications for generator monitoring and controls
integration
*The standard myPV ClearSky drawing packages for 15kV, 25kV, and 35kV products
note the height changes to the overall padmount equipment dimensions based on these
options.
**The addition of this component alters the overall pad mounting requirements, conduit
spacing, length, and weight of the padmount gear. These changes are not represented
by the standard specifications, and require a the Customer to reference a dedicated
drawing package.
2021 Product Line Modifications
We make every effort to understand, anticipate, and listen to our customers’ needs. The
2021 myPV ClearSky product line introduces the following modifications when
compared to the prior model year:
External voltage compartment doors are now clearly labeled as “Utility Side” or
“Solar Side”
Both Utility side and Solar Side MV Terminations are now dead-front style, MV
separable connections (IEEE 386 Interfaces)

Introduction
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The MV separable connections have been moved vertically to provide a minimum
additional 5” of space for cable management
The MV Termination compartments are nominally 6” deeper (front to back) to allow
for MV elbow stacking and accessories
The internal VFI 3-phase Ganged breaker has been upgraded to three (3)
independent VFI 1-phase breakers, supporting both local push-button single-phase
testing operations as well as remote SCADA 1-phase trip operations as well
A second wire-glass viewing window has been added (opposite the first) to allow for
improved cabinet internal component inspections from the outside
The control cabinet now has a dedicated chase to allow for network cable routing
via the MV cabinet (no external conduit runs are required)
Metering and Relaying CTs are now clearly labeled for both phase and orientation in
the event they are unmounted during MV cable management
The myPV IQ™ - Remote Interface and integrated cellular modem have been
added to the standard product offering to support remote commissioning and
troubleshooting by Customers, Customer assign Engineering resources, and Solar-
Ops support staff.

Resources
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Resources
The myPV ClearSky™ Interconnection is a standardized product, supported by
documentation and resources to ensure your success.
Technical Documents
For the most up to date product drawings, CAD blocks, and application guides visit our
Technical Documents page by registering on our Support Resources page.
MV Separable Connectors
Also referred to as “Elbows”, separable connectors are medium voltage (MV)
components that provide a watertight, fully electrically insulated, electrical termination
for MV conductors on both the Utility and Solar sides of the myPV ClearSky. All MV
separable connectors support IEEE 386 compliant interfaces.
Technical Documents
MV Separable Connectors
Product Line Specifications
Product Photos
Frame Size by Voltage Class
Continuous Current Sizing
Instrument Transformers

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Although we do not have any preference for brand of manufacture, Eaton and ABB both
have excellent product catalogs that illustrate the breadth of available products, how
they may be used, and available part numbers.
Major Manufacturers Include:
ABB - Elastimold [PDF]
Eaton - Cooper Power Systems [PDF]
3M - Separable Connectors [PDF]
Product Line Specifications
The myPV ClearSky product line is available in three (3) frame sizes that are
determined by maximum voltage rating. A standard set of options may be added to any
of the frame sizes to configure the standard product to meet individual customer
requirements. The standard product specifications are listed below:

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myPV ClearSky™ 2021 - Product Line Representative Cross Section
For myPV ClearSky™ products that have selected to add the option of a Solar-Side 3-
Pole Ganged Load-Break Disconnect the following specifications should be used
instead:

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Product Photos
While myPV ClearSky products do vary in size, all product frame sizes are arrange in
the same manner. The following orthographic photos provide a visual reference for
common locations of common features.

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Frame Size by Voltage Class
myPV ClearSky is available in three (3) frame sizes that are determined by the facility’s
line-to-line voltage rating.
Applications that have interconnection voltages equal to or below 35kV (line-to-line) are
supported.
Determine Your Facility’s Voltage Class:

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Continuous Current Sizing
All myPV ClearSky frame sizes support a maximum continuous current rating of 600A.
Determine Your Facility’s Continuous Current Sizing:
Instrument Transformers
Potential Transformers (PTs) and Current Transformers (CTs) are devices used to
measure voltage and current respectively.
The myPV ClearSky has a single set of three (3) revenue grade PTs that are shared for
metering and protection relaying functions. A fourth control power PT is used for control
power (discussed inDesign Considerations).
The myPV ClearSky has two sets of three (3) CTs however. The first set is dedicated to
review grade metering, while the second set is dedicated to protective relaying. The
revenue grade CTs are specified to provide high accuracy measurements throughout
the high, mid, and low range of expected current flow to ensure proper power readings.

Resources
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The protection CTs are specified to provide operation on the higher end of expected
current flow to accurately capture (over current) fault events.
NOTE: A fourth CT can be used to directly measure neutral current, however most
meters and relays are capable of accurately calculating neutral current without a
physical CT being installed.
PTs step down the interconnection voltage to a range that the meter’s inputs can accept
… typically a nominal 120V. As an example, the ratio of a PT (e.g. 60:1) will result in a
voltage at the meter of 119.993V for a 12.47kV interconnection.
The Math:
The Interconnection Voltage: 12.47 kV * 1000 = 12,470V L-L
The Line Voltage: 12,470V L-L / sqrt(3) = 7,199.558V L-N
The PT’s Output Voltage: 7,199.558V L-N / 60 = 119.993V
Most meters will accept PT voltages up to 300V or even 600V, so sizing a PT to achieve
120V is more of a rule of thumb that a requirement … ensuring the PT has appropriate
accuracy throughout the range of expected current flow (0 to the Export Limit or your
Facility) is more important.
CTs similarly step down the interconnection current flow to a range that the meter’s
inputs can also accept … typically a nominal 5A. As an example, the ratio of a CT (e.g.
300:5) will result in current at the meter of 5A for 300A of current flow.
The Math (Expected Current Flow for a 12.47kV Interconnected, 5,000kW Facility):
The Interconnection Voltage: 12.47 kV * 1000 = 12,470V L-L
The Line Voltage: 12,470V L-L / sqrt(3) = 7,199.558V L-N
Facility Wattage: (5,000kW * 1000) = 5,000,000W
Facility Total Amperage: 5,000,000W / 7,199.558V L-N = 694.487A
Line Amperage (3-Phase System): 694.487A / 3 = 231.496A
Now that we know are maximum expected current flow is 232A, we can choose an
appropriate CT ratio.
For metering, we may choose a 300:5. The 232A falls into the mid-range of the 300A
rating, however we could also safely choose a 200:5 so long as the CT has an
appropriate “rating factor” which will typically allow a CT to operate at 1.5 or 2.0 of its

Resources
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nameplate while still maintaining proper accuracy. To make this determination, the CTs
rating curves should be consulted to ensure the CT rating is appropriate for your
application.
For relaying however, we may choose a higher ratio CT, possibly a 400:5. This higher
ratio will provide better measurements of fault current conditions that are typically much
larger than the system’s normal operating conditions. A 400:5 CT with a rating factor of
2.0 will provide measurements of up to 800A before saturating.
Regardless of what PT or CT ratio is ultimately selected, the meter and protection relay
devices are configured to understand what instruments are connected via the PTR
(Potential Transformer Ratio, 60: 1 = 60) and CTR (Current Transformer Ratio, 300:5 =
60) settings variables.
The selection of instrument transformers is specific to the application, the
interconnection and facility electrical characteristics, and also an Engineer’s preference.
For the myPV ClearSky™, we have assembled the following table of standard part
numbers for PTs and CTs to use, unless otherwise specified buy the Customer:

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