The Ultimate DIY Guide: Installing a 5kW Solar System (Grid-Tied & Off-Grid) | International Power Quality Discussion Forum

Author: Denis Ruest, P.Eng/IPQDF
Skill Level: Advanced DIY (Electrical experience required)
Voltage: 120/240V Split-Phase
System Size: 5kW (kilo Watts)

1. Introduction: Understanding Your Goal

A 5kW solar system is a significant investment that can power most of a medium-sized home. Using 14 panels (rather than 13) creates balanced string configurations—two equal strings of 7 panels each—simplifying wiring, improving electrical balance, and making troubleshooting easier.

Before buying parts, you must decide: Grid-Tied or Off-Grid?

Grid-Tied: You remain connected to the utility. You can sell power back (Net Metering) but the system shuts down during a grid outage for safety (Anti-Islanding). A 5kW grid-tied system typically produces 20-25 kWh per day, enough to offset average household usage.
Off-Grid: You are completely independent from the utility. Requires a substantial battery bank (48V @ 200Ah or more). The system runs 24/7 regardless of the grid. A 5kW off-grid system can run refrigerators, lights, electronics, and even small air conditioners or well pumps in cycles.

Disclaimer: Working with electricity is dangerous. Consult a licensed electrician for final connections. Permits are required by your local jurisdiction for systems of this size. This article is for informational purposes and does not replace a licensed professional.

2. Why 14 Panels? The Even Number Advantage

Using 14 panels (two strings of 7) offers significant benefits over 13 panels:

Feature	13 Panels (7+6)	14 Panels (7+7)
String Balance	Unequal strings	Perfectly balanced
Voltage Matching	Different string voltages	Identical string voltages
Combiner Box	Requires different fusing	Identical fusing for both strings
Performance	One string produces less	Equal production from both
Expandability	Awkward configuration	Easy to add pairs later
Total Power	~5.0kW (with 385W panels)	~5.4kW (with 385W panels)

With 14 x 385W panels, you get 5,390W—a nice buffer above 5kW that helps on cloudy days without overloading most 5kW inverters (which typically accept up to 6,000W DC input).

3. Tools & Materials Checklist

Tools Required:

Drill & Impact Driver with hex bits
Socket Set & Wrenches (metric and standard)
Wire Strippers/Cutters (10 AWG to 2/0 AWG capable)
Digital Multimeter with DC voltage capability up to 600V
PV (Solar) Safety Gloves (insulated)
Torque Wrench (inch-pounds and foot-pounds)
Stud Finder (electronic)
Chalk Line
Conduit Bender (1/2″ and 3/4″)
Fish Tape
Cable Lugs Crimping Tool (hydraulic recommended for battery cables)

Materials for a 5kW System (14 Panels):

Solar Array:

Solar Panels: 14x 360W-400W panels (total 5.0-5.6kW). Choose high-efficiency monocrystalline panels to minimize roof space.
Racking System: Aluminum rails, L-feet, mid-clamps, end-clamps, flashing (IronRidge, Unirac, or SnapNrack). Ensure rated for wind/snow loads in your area.
Grounding: Grounding lugs, WEEB washers, or copper wire.

DC Electrical:

Combiner Box: Weatherproof enclosure with 2-string capability.
String Fuses: 15A fuses or breakers for each string (2 required, identical ratings).
PV Wire: 10 AWG or 8 AWG for panel interconnections, 6 AWG for home run.
DC Disconnect: 30A or 60A outdoor-rated safety switch.

Inverter:

Grid-Tied Option: 5kW String Inverter (SMA, SolarEdge, Fronius) or 5kW of Microinverters (Enphase IQ8+). Verify max DC input accommodates ~5.4kW.
Off-Grid Option: 5kW Split-Phase All-in-One Unit with built-in charge controller (Growatt SPF 5000 ES, MPP Solar LVX6048, Victron MultiPlus-II). Must accept 48V DC input.

AC Electrical:

AC Breaker Panel: Main panel or sub-panel.
Double-Pole Breaker: 30A for solar backfeed.
THHN Wire: 10 AWG copper (color-coded: black, red, white, green).
AC Disconnect: Outdoor-rated safety switch (if required by code).

Off-Grid Only:

Battery Bank: 48V Lithium Iron Phosphate (LiFePO4) batteries. Minimum 100Ah (5kWh), Recommended 200Ah (10kWh) for overnight loads. Examples: EG4 LL, Trophy Battery, Pylontech.
Battery Cables: 2/0 AWG or 4/0 AWG welding cable with lugs.
Class-T Fuse: 250A or 300A with holder.
Busbars: Heavy-duty copper busbars for battery connections.
Battery Rack: Server rack or shelf system.

Consumables:

Wire nuts / Wago connectors
Cable ties (UV-resistant for outdoors)
Conduit (Schedule 40 PVC or EMT)
Penetration sealant (roofing caulk)
Electrical tape
Label maker / UV-resistant labels

4. System Design & Layout (The Paperwork Phase)

[Image: A sketch on graph paper of a roof with 14 panels arranged in two neat rows of 7, south arrow, and string diagram]

Before lifting a single panel, you must complete the design on paper. This is required for permits and ensures your components work together safely.

Step 4.1: Roof Assessment

Orientation: South-facing is best in the Northern Hemisphere. Southeast or Southwest will lose 10-15% production.
Pitch: Most roofs work, but steep pitches (greater than 45°) require special safety equipment.
Condition: Ensure your roof has at least 10 years of life remaining. Re-roofing after solar installation is expensive.
Obstructions: Measure distances from chimneys, vents, and skylights. You need 18-36 inches of clearance around the array for fire access (check local codes).
Layout: With 14 panels, you can arrange them in two rows of 7 (landscape orientation) or seven rows of 2 (portrait orientation). Two rows of 7 is most common.

Step 4.2: String Sizing Calculation (Perfect Balance)

With 14 panels, you create two identical strings of 7 panels each.

Panel Voltage: Most modern 400W panels have a Voc (open circuit voltage) around 40-45V.
String A: 7 panels x 45V = 315V (operating) / 365V (max cold temp)
String B: 7 panels x 45V = 315V (operating) / 365V (max cold temp)
Total Power: Both strings combine in parallel at the combiner box, producing identical voltage and balanced current.

Critical: Use a string sizing calculator (available on inverter manufacturer websites) with your location’s record low temperature. Cold increases voltage and can destroy your inverter if not calculated correctly. With 7-panel strings, you’ll have plenty of safety margin below the typical 600V max inverter input.

Step 4.3: Production Estimate

A 5.4kW system (14 x 385W) in an area with 5 peak sun hours will generate:

Daily: 5.4kW x 5hrs x 0.8 (system losses) = 21.6 kWh/day
Monthly: 21.6 kWh x 30 = 648 kWh/month
Annually: Varies by season, typically 7,000-9,000 kWh/year

This covers 60-100% of an average home’s usage depending on efficiency.

Step 4.4: Permitting

Visit your local building department with:

Site plan showing roof dimensions
Panel layout diagram (14 panels clearly shown)
Electrical one-line diagram
Equipment spec sheets
Structural calculations (if required)

Wait for approval before purchasing equipment or starting installation.

5. Install the Racking (Mounting Hardware)

[Image: Flashing installed under lifted shingles with a lag bolt driven into a rafter, safety harness visible]

The racking system is the foundation of your solar array. A 5kW system with 14 panels weighs approximately 650-850 pounds and must withstand wind uplift forces.

Step 5.1: Locate Rafters

Use an electronic stud finder to locate rafters. Mark them with chalk lines across the roof area.
Standard rafter spacing is 24″ on center. If your spacing is wider, you need structural reinforcement.
Mark all rafter locations clearly—you’ll need this for every mounting point.
For 14 panels in two rows, you’ll need mounting points at each rafter intersection with the rails.

Step 5.2: Install Flashing

Carefully lift shingles where the mount will go. Use a flat bar to avoid cracking shingles.
Slide aluminum flashing completely under the shingle, with the top edge under the course above.
The flashing should have a built-in sealant or you should apply roofing caulk under it.

Step 5.3: Attach L-Feet

Drill a pilot hole through the flashing and into the rafter center. Use a stop on your drill bit to prevent drilling too deep.
Insert a lag bolt (typically 3/8″ x 4″ stainless steel) with a built-in washer.
Tighten firmly but do not over-torque. The goal is to compress the flashing without deforming it.
Seal the bolt head with additional roofing caulk.

Step 5.4: Install Rails

Attach aluminum cross rails to the L-feet using T-bolts and caps.
For 14 panels in two rows of 7, you’ll need two horizontal rails running the full width of the array.
Ensure rails are perfectly level side-to-side and front-to-back. Use a 4-foot level.
Join rail sections using internal splices if your run is longer than available rail lengths. Ensure splices are tight and straight.

Safety Tip: Wear a harness with a roof anchor at all times. Falling from a roof can be fatal.

6. Mount the Solar Panels

Step 6.1: Stage Panels Safely

Hoist panels onto the roof using panel lifters, roof hooks, or handing them up carefully.
With 14 panels, work systematically—stage panels for one row at a time.
Place panels face-down on foam pads to protect the glass while you prepare wiring.

Step 6.2: Pre-Wire (Optional but Recommended)

If accessible, attach MC4 extension cables to the panel junction boxes before mounting.
This is easier on the ground or with panels flipped over than when they’re mounted.
For 14 panels, you’ll have 14 positive and 14 negative leads to organize.

Step 6.3: Position Panels

Start at one corner of the array. Place the first panel onto the rails.
Work across the row, then start the second row.
Panels should sit on the rails with the frame resting on the clamps.

Step 6.4: Secure with Clamps

Mid-Clamps: Used between panels. They clamp the frames of two adjacent panels to the rail. You’ll need approximately 22 mid-clamps.
End-Clamps: Used at the ends of each rail to secure the last panel. You’ll need 4 end-clamps per rail (8 total).
Torque all clamps to manufacturer specifications (typically 15-20 ft-lbs). Under-torquing risks panels blowing away; over-torquing can crack the frames.

Step 6.5: Ground the Array

Use WEEB (Washer Electrical Equipment Bond) clips that pierce the anodized coating on rails and panel frames.
Alternatively, run a continuous bare copper ground wire bonded to each rail with listed grounding lugs.
Connect the array ground to the home’s grounding electrode system.

7. Electrical Wiring (DC Side)

[Image: Close-up of MC4 connectors clicking together, then a diagram showing 2 identical strings of 7 panels merging in a combiner box]

With 14 panels, you create two perfectly matched strings of 7 panels each.

Step 7.1: Configure the Strings

String A (7 panels): Connect positive (+) of panel 1 to negative (-) of panel 2, and so on through all 7 panels. The end will have one free positive and one free negative.
String B (7 panels): Repeat the process for the remaining 7 panels, following the same pattern.

Step 7.2: Voltage Check

Before connecting to the inverter, measure each string voltage with a multimeter on a sunny day.
String A should read approximately 280-320V DC (depending on panel specs and sunlight).
String B should read identical voltage to String A (within 1-2V).
Record these values for your records. Matched voltages confirm proper wiring.

Step 7.3: Run Wires to Combiner Box

Run the positive and negative wires from each string down to the combiner box location (usually near the array edge or on the wall below).
Use PV wire rated for outdoor exposure and sunlight.
Label each wire pair clearly: “String A +”, “String A -“, “String B +”, “String B -“.

Step 7.4: Install Combiner Box

Mount the weatherproof combiner box on the wall near the array or on the roof edge.
Inside the box, connect each string positive to a 15A fuse or breaker (identical for both strings).
Connect each string negative to a common negative busbar.
The combined output goes to a single positive and negative wire (the “home run”).

Step 7.5: Run Home Run to DC Disconnect

From the combiner box, run 6 AWG PV wire (positive and negative) down to the DC disconnect switch mounted outside near the inverter.
Use conduit for protection where wires are exposed.
Label this wire “PV Array Output 5.4kW” at both ends.

8. Mount the Inverter & AC Panel

Step 8.1: Select Location

Indoors (garage/basement) is ideal for inverter longevity.
Outdoors requires a NEMA 4X rated inverter.
Location must be close to the main electrical panel to minimize AC wire runs.
For off-grid, location must be close to the battery bank (battery cables must be short).

Step 8.2: Install Backboard

Mount a 4′ x 4′ sheet of 3/4″ plywood on the wall. Paint it with fire-retardant paint if required by code.
This provides a solid mounting surface and organizes equipment.

Step 8.3: Mount Inverter

Inverter weight: 5kW units weigh 50-100 pounds. Use lag bolts into studs.
Maintain manufacturer-specified clearance (typically 6-12 inches on all sides) for airflow.
Ensure the inverter is level.

Step 8.4: Mount AC Panel

If using a sub-panel for critical loads (off-grid), mount it next to the inverter.
If backfeeding the main panel (grid-tied), ensure the main panel has an open double-pole breaker slot.

Step 8.5: Install Disconnects

Mount the DC disconnect (between combiner box and inverter) within sight of the inverter.
Mount the AC disconnect (between inverter and main panel) if required by local code.

9. Battery Bank Wiring (Off-Grid Only)

[Image: A rack of blue lithium batteries wired in series-parallel to create 48V, with heavy cables and a Class-T fuse]

A 5kW inverter at 48V draws 104 Amps at full load. This requires serious cabling and safety protection.

Step 9.1: Select Battery Configuration

48V System: Most 5kW off-grid inverters require a 48V battery bank.
Capacity: For a 5kW load to run overnight (say 10 hours at partial load), you need at least 10kWh of storage.
Typical Setup with 14 Panels: With 5.4kW of solar, you can charge a substantial battery bank. Recommended: 48V @ 200Ah (10kWh) minimum, 48V @ 300Ah (15kWh) ideal.
Configuration Options:
- 4x 12V 200Ah batteries in series = 48V @ 200Ah (10kWh)
- 8x 12V 200Ah in series-parallel = 48V @ 400Ah (20kWh)
- 3x 48V server rack batteries in parallel = 48V @ 300Ah (15kWh)

Step 9.2: Position Batteries

Place batteries on a rack or shelf. Never place directly on concrete floor (cold can damage them).
Ensure adequate ventilation—batteries can off-gas (even lithium in fault conditions) and generate heat.

Step 9.3: Wire Batteries

Use 2/0 AWG or 4/0 AWG welding cable for all battery interconnections.
Crimp heavy-duty lugs onto cables using a hydraulic crimper.
For series connections: Connect positive of battery 1 to negative of battery 2, etc.
For parallel strings: Connect all positives together on a busbar, all negatives together on a busbar.

Step 9.4: Install Class-T Fuse

CRITICAL: Install a Class-T fuse within 12 inches of the battery positive terminal.
Fuse sizing: Inverter max continuous current x 1.25 = fuse size. For 104A x 1.25 = 130A minimum. Most 5kW inverters use 200A-250A fuses to handle surge loads.
The Class-T fuse protects against short circuits—batteries can deliver thousands of amps in a fault, causing fire or explosion.

Step 9.5: Connect to Inverter

Run the positive cable from the fuse to the inverter battery positive terminal.
Run the negative cable directly from the battery negative busbar to the inverter battery negative terminal.
Torque all connections to manufacturer specifications.

Step 9.6: Install Battery Monitor (Optional)

Install a shunt-based battery monitor (Victron BMV-712 or similar) to track state of charge accurately.
This is essential for off-grid living to know how much capacity remains.

10. AC Wiring (Grid-Tied & Off-Grid)

[Image: An electrician wiring a 30A double-pole breaker in a main electrical panel, labeled “Solar”]

Step 10.1: Understand the Math
5,400 Watts at 240 Volts = 22.5 Amps continuous (at full 5.4kW output).
National Electrical Code requires circuits to be sized at 125% of continuous load:

22.5A x 1.25 = 28.1A
Therefore, you need a 30A double-pole breaker (next standard size above 28.1A).

Step 10.2: Wire Gauge Selection

For a 30A breaker, use 10 AWG copper wire (minimum).
If the run from inverter to main panel exceeds 100 feet, upgrade to 8 AWG to prevent voltage drop.
Use color-coded THHN wire: Black (L1), Red (L2), White (Neutral), Green (Ground).

Step 10.3: Off-Grid Connection

Run L1, L2, Neutral, and Ground from the inverter output to a dedicated “Critical Loads” sub-panel.
In the sub-panel, install standard 15A and 20A breakers for circuits you want backed up (refrigerator, lights, internet, etc.).
Transfer those circuits from the main panel to the sub-panel.

Step 10.4: Grid-Tied Connection (Backfeeding)

Run L1, L2, Neutral, and Ground from the inverter output to the main service panel.
Install the 30A double-pole breaker in an open slot at the opposite end of the panel from the main breaker (this helps with the 120% rule).
Connect L1 to one terminal of the breaker, L2 to the other terminal. Connect Neutral to the neutral busbar, Ground to the ground busbar.
Label the breaker “SOLAR 5.4kW” clearly so future electricians know it’s backfed.

Step 10.5: The 120% Rule (Critical for Grid-Tied)

Your main panel busbar has a rating (usually 100A, 125A, or 200A).
The sum of the main breaker and the solar backfeed breaker cannot exceed 120% of the busbar rating.
Example: 125A busbar x 1.2 = 150A maximum. 100A main + 30A solar = 130A, which is acceptable.
If your panel can’t accommodate this, you need a “Supply Side Tap” (connection before the main breaker), which requires an electrician.

11. Final Connections & Power-On Sequence

[Image: A person using a multimeter to check voltage at the DC disconnect before turning it on]

Step 11.1: Pre-Power Checks

Visual Inspection: Check every wire connection. Look for loose strands, nicked insulation, or incorrect routing.
Polarity Check: Verify positive goes to positive, negative to negative everywhere. Reversed polarity on a charge controller or inverter will destroy it instantly.
Torque Check: Ensure all terminal screws are torqued to spec. Loose connections cause arcing and fires.
Voltage Check (DC): Measure voltage at the DC disconnect. Both strings should show identical voltage (within 2V).
Voltage Check (AC): Ensure main panel is energized and voltage is 120/240V ±5%.

Step 11.2: Turn-On Sequence (Grid-Tied)

Turn on the AC breaker from the main panel to the inverter (grid power).
Wait for inverter display to power up and show grid parameters.
Turn on the DC disconnect from the solar array.
The inverter should detect solar power, synchronize with the grid (takes 2-5 minutes), and begin exporting.
Verify display shows “Producing” or “Grid-Tied” mode with positive wattage. With 14 panels, you should see 4.5-5.4kW near solar noon.

Step 11.3: Turn-On Sequence (Off-Grid)

Ensure all AC loads are turned off.
Turn on the DC battery breaker or disconnect first.
Inverter screen should light up. Verify battery voltage reads correctly.
Turn on the solar DC disconnect.
The charge controller should activate and begin charging batteries (Bulk mode). Voltage should rise.
Turn on the inverter AC output breaker.
Test by turning on a small load (like a light). The inverter should power it.
Gradually add larger loads to test system response.

Step 11.4: Observe Initial Operation

Let the system run for 30 minutes. Watch for:
- Unusual noises (buzzing, arcing)
- Overheating components
- Error codes on the display
- Inverter fans cycling properly
With balanced strings, both should contribute equally—check inverter display for per-string data if available.

12. Monitoring & Performance Testing

[Image: A smartphone screenshot showing a solar monitoring app with 5.4kW production and 26.5 kWh daily total]

Step 12.1: Connect Monitoring

Most modern inverters have Wi-Fi or Ethernet connectivity.
Download the manufacturer’s app and create an account.
Register the inverter using its serial number.
Connect to your home network and verify data transmission.

Step 12.2: Verify Production

On a clear day near solar noon, your 5.4kW system should produce 4.6kW – 5.2kW depending on:
- Panel temperature (hot panels produce less)
- Angle relative to sun
- Atmospheric conditions
If production is significantly lower, check for shading issues or wiring problems.
Compare the two strings—they should show nearly identical output.

Step 12.3: Daily/Annual Expectations

Daily: 22-32 kWh depending on season
Monthly: 660-960 kWh
Annual: 8,000-11,000 kWh (varies by location)

Step 12.4: Off-Grid Specific Monitoring

Track battery state of charge daily.
Note what time batteries reach full charge (indicates array sizing adequacy).
Note what time batteries reach low charge (indicates if more capacity needed).
Adjust usage habits if needed to stretch through the night.

13. Labeling & Documentation

[Image: A clean electrical panel with professionally printed labels on every breaker and wire]

Code requires specific labeling for safety:

Required Labels:

DC Disconnect: “PHOTOVOLTAIC SYSTEM DISCONNECT – 5.4kW DC”
AC Disconnect: “SOLAR AC DISCONNECT – 5.4kW”
Backfed Breaker: “SOLAR 5.4kW” (on the breaker itself)
Main Panel: Warning label stating “THIS EQUIPMENT SUPPLIED BY MULTIPLE SOURCES – SOLAR 5.4kW” (if backfeeding)
Inverter: Manufacturer label with ratings visible
Combiner Box: “STRING A (7 PANELS)” and “STRING B (7 PANELS)” on each fuse
All Conductors: Identify at each termination point with voltage and source

Documentation to Keep:

Permit approval documents
Equipment manuals
One-line diagram with actual wire lengths noted
Warranty information
Monitoring login credentials
Emergency shutdown procedure (post near main panel)
Panel layout diagram showing which panels belong to which string

14. Common Mistakes to Avoid

Mistake #1: Undersizing Wire

A 5.4kW system pulls serious current. Using 14 AWG wire for battery connections or long DC runs causes voltage drop and fire risk.
Solution: Always use voltage drop calculators and follow NEC ampacity tables. With 14 panels, your home run current is higher—use 6 AWG minimum.

Mistake #2: Ignoring Temperature Effects on Voltage

Cold temperatures increase panel voltage. Panels rated 40V at 25°C can reach 48V at -10°C.
Solution: Calculate string voltage using the record low temperature for your area. With 7-panel strings, you have good safety margin.

Mistake #3: Mixing Panel Types in Strings

Panels in series must have the same amperage. Panels in parallel must have the same voltage.
Solution: Buy identical panels for the entire 14-panel array. Don’t mix old and new.

Mistake #4: Skipping the Battery Fuse (Off-Grid)

Batteries can deliver thousands of amps in a short circuit. Without a fuse, wires will melt and cause fire.
Solution: Always install a Class-T fuse within 12 inches of the battery positive terminal.

Mistake #5: Not Torquing Connections

“Hand tight” is not acceptable for electrical connections. Loose connections arc, overheat, and fail.
Solution: Use a torque wrench on every lug and terminal. Record torque values.

Mistake #6: Improper Grounding

Solar arrays can build up static charge and are vulnerable to lightning.
Solution: Bond all metal parts (rails, panel frames) and connect to the home’s grounding electrode system.

Mistake #7: Forgetting the 120% Rule (Grid-Tied)

Overloading the main panel busbar is a fire hazard.
Solution: Calculate busbar rating, main breaker size, and solar breaker size before installing.

Mistake #8: Unbalanced Strings

With 14 panels, you have the opportunity for perfect balance. Don’t create uneven strings.
Solution: Keep both strings at 7 panels each for identical voltage and current.

15. When to Call a Professional

While this guide is for DIY enthusiasts, certain tasks require licensed electricians:

Main Panel Modifications: If you need to replace the main panel or move the main breaker.
Supply Side Taps: If your panel can’t accommodate the 120% rule, a supply-side connection requires utility involvement and professional installation.
Service Upgrade: If your main service is too small (e.g., 60A service) to handle solar plus existing loads.
Utility Meter Socket Work: Anything that requires pulling the meter or modifying the meter socket.
Final Inspection: Many jurisdictions require a licensed electrician to pull the permit and perform final connections.

16. System Specifications Summary

Component	Specification
System Size	5.4 kW DC (with 385W panels)
Panels	14x 360W-400W monocrystalline
Roof Space Required	~250-280 sq ft
String Configuration	2 strings of 7 panels (perfectly balanced)
String Voltage	Each string: ~315V operating / ~365V max
DC Wire (Home Run)	6 AWG PV wire
Inverter Output	5,000W continuous @ 240V (accepts 5.4kW DC)
AC Breaker Size	30A double-pole
AC Wire	10 AWG (8 AWG for long runs)
Battery (Off-Grid)	48V @ 200Ah minimum (10kWh)
Battery Cable (Off-Grid)	2/0 AWG or 4/0 AWG
Battery Fuse (Off-Grid)	Class-T, 200A-250A
Daily Production	22-32 kWh (varies by location)

17. Conclusion

A 5kW solar system using 14 panels offers the perfect balance of power output and electrical symmetry. With two identical strings of 7 panels each, you get:

Simpler wiring with identical components
Better performance with balanced power production
Easier troubleshooting when both strings behave identically
More power (5.4kW vs 5.0kW) for minimal additional cost
Future expansion potential by adding pairs of panels

When properly installed, this system will provide clean energy for 25+ years, reduce or eliminate electric bills, and increase your energy independence.

Final Safety Reminder:

Obtain all required permits before starting
Work with a partner—never alone on a roof or with high voltage
Use lockout/tagout procedures when working on electrical panels
When in doubt, consult a licensed electricien.