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Introduction: Essential PV Array Protection Infrastructure<\/h2>\n\n\n\n

A solar fuse panel (also called a PV combiner box) consolidates multiple solar array strings into a single output while providing individual overcurrent protection for each string. This critical component prevents reverse current damage, enables string-level isolation, and ensures NEC-compliant installation for residential and commercial photovoltaic systems.<\/p>\n\n\n\n

This comprehensive installation guide covers fuse panel selection, NEC 690 sizing requirements, busbar layout design, wire termination methods, grounding procedures, and professional mounting techniques for reliable long-term solar system performance.<\/p>\n\n\n\n

Why Dedicated Solar Fuse Panels Are Required<\/h3>\n\n\n\n

Individual residential solar panels cannot be directly paralleled without protection:<\/p>\n\n\n\n

Reverse Current Hazard:<\/strong><\/p>\n\n\n\n

Normal Operation (all panels producing):\nString 1: 10A \u2192 Combiner \u2192 40A total output\nString 2: 10A \u2197\nString 3: 10A \u2197\nString 4: 10A \u2197<\/code><\/pre>\n\n\n\n
Fault Condition (String 1 shaded\/damaged): String 1: 0A \u2190 30A REVERSE CURRENT from other strings! String 2: 10A \u2192 Combiner \u2192 30A output String 3: 10A \u2197 String 4: 10A \u2197<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Result without fuse: String 1 panels overheat and fail Result with fuse: String 1 fuse opens, isolates fault<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
NEC Requirements for Fuse Panels:<\/strong>
– NEC 690.9(A): Overcurrent protection required if 3+ strings paralleled
– NEC 690.16: Current-limiting overcurrent devices for certain systems
– NEC 690.31(C): Accessible disconnecting means
– NEC 110.26: Working space clearances
– NEC 312: Enclosure requirements<\/p>\n\n\n\n
Common Applications:<\/strong>
– Residential rooftop solar (4-12 string combiner)
– Commercial solar arrays (12-24 string combiner)
– Ground-mount solar farms (large multi-string combiners)
– Off-grid battery charging systems
– Grid-tie inverter input protection<\/p>\n\n\n\n
NEC 690 Fuse Sizing Requirements<\/h2>\n\n\n\n
String Fuse Rating Calculation (NEC 690.9)<\/h3>\n\n\n\n
Step 1: Determine String Short-Circuit Current (Isc)<\/strong><\/p>\n\n\n\n
Example Solar String:\n8\u00d7 400W panels in series\nPer panel Isc: 10.5A\nString Isc: 10.5A (series = same current)\n<\/code><\/pre>\n\n\n\n
Step 2: Apply 156% Safety Factor (NEC 690.8(B)(1))<\/strong><\/p>\n\n\n\n
Required fuse rating \u2265 String Isc \u00d7 1.56<\/code><\/pre>\n\n\n\n
Calculation: 10.5A \u00d7 1.56 = 16.38A minimum<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Select next standard fuse size: 20A gPV fuse<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Why 156% Factor:<\/strong>
– 125% for continuous current (>3 hours)
– 125% for high irradiance conditions
– Combined: 1.25 \u00d7 1.25 = 1.56 (156%)<\/p>\n\n\n\n
Step 3: Verify Wire Protection<\/strong><\/p>\n\n\n\n
String wire: 10 AWG (ampacity 40A at 75\u00b0C per NEC Table 310.16)\nFuse selected: 20A\nVerification: 20A < 40A ampacity \u2713 PASS<\/code><\/pre>\n\n\n\n
If fuse were 50A: 50A > 40A wire capacity \u2717 FAIL (fire hazard!) Solution: Upsize wire to 8 AWG (50A ampacity)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Combiner Output Fuse Sizing<\/h3>\n\n\n\n
Total Output Current Calculation:<\/strong><\/p>\n\n\n\n
System: 4 strings, 10.5A Isc each\nTotal output: 4 \u00d7 10.5A = 42A maximum<\/code><\/pre>\n\n\n\n
Output fuse sizing: 42A \u00d7 1.25 (continuous) = 52.5A minimum Select: 60A gPV fuse<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Output wire sizing: 60A fuse requires minimum 6 AWG (65A ampacity) Voltage drop check: Calculate for actual run length<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Series String Voltage Consideration:<\/strong><\/p>\n\n\n\n
String voltage: 8\u00d7 400W panels\nVoc per panel: 49.2V\nString Voc: 49.2V \u00d7 8 = 393.6V<\/code><\/pre>\n\n\n\n
Temperature correction (NEC 690.7): Cold temperature: -10\u00b0C (common winter low) Correction factor: 1.12 (from manufacturer datasheet) Maximum voltage: 393.6V \u00d7 1.12 = 440.8V<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Required fuse voltage rating: \u2265500V DC minimum Select: 600V DC rated gPV fuses (standard rating)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
\"Solar<\/figure>\n\n\n\n
Fuse Panel Component Selection<\/h2>\n\n\n\n
gPV-Rated Fuses vs. Standard DC Fuses<\/h3>\n\n\n\n
What “gPV” Rating Means:<\/strong><\/p>\n\n\n\n
g = Full-range breaking capacity (German: ganzbereichsschutz)\nPV = Photovoltaic application<\/code><\/pre>\n\n\n\n
gPV certification indicates: – Tested for DC photovoltaic reverse current interruption – Rated for high ambient temperature (70-90\u00b0C typical) – UV-resistant materials for outdoor mounting – Complies with IEC 60269-6 or UL 2579 standards – Approved for ungrounded PV systems<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Why Standard DC Fuses Are Inadequate:<\/strong><\/p>\n\n\n\n
Standard DC Fuse (Not gPV):\n- Rated for uni-directional current only\n- Designed for forward current interruption\n- Not tested for reverse current from paralleled sources\n- Lower ambient temperature rating (40\u00b0C typical)<\/code><\/pre>\n\n\n\n
Solar Array Unique Conditions: – Reverse current from other strings (backfeed) – High ambient temperature (rooftop 70\u00b0C+ common) – Outdoor UV exposure for 25+ years – Ungrounded system voltage stress<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Result: Standard DC fuse may fail catastrophically – Cannot interrupt reverse current safely – Overheats at high ambient temperature – UV degradation causes premature failure<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
gPV Fuse Specifications:<\/strong><\/p>\n\n\n\n
Rating<\/th>Voltage<\/th>Interrupt Capacity<\/th>Ambient Temp<\/th>Cost<\/th><\/tr><\/thead>
10A gPV<\/td>600V DC<\/td>20kA typical<\/td>90\u00b0C<\/td>$8-12<\/td><\/tr>
15A gPV<\/td>600V DC<\/td>20kA typical<\/td>90\u00b0C<\/td>$8-12<\/td><\/tr>
20A gPV<\/td>600V DC<\/td>20kA typical<\/td>90\u00b0C<\/td>$10-15<\/td><\/tr>
30A gPV<\/td>600V DC<\/td>20kA typical<\/td>90\u00b0C<\/td>$12-18<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
Busbar Material and Sizing<\/h3>\n\n\n\n
Copper vs. Aluminum Busbars:<\/strong><\/p>\n\n\n\n
Copper (Preferred):<\/strong><\/p>\n\n\n\n
Advantages:\n- Lower resistance (1.68 \u00d7 10\u207b\u2078 \u03a9\u00b7m)\n- Better conductivity\n- Easier to solder\/terminate\n- Corrosion-resistant with proper coating<\/code><\/pre>\n\n\n\n
Disadvantages: – Higher cost ($20-40 per busbar) – Heavier weight<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Typical sizing for 4-string combiner: – 1\/4″ thick \u00d7 2″ wide \u00d7 12″ long – Ampacity: 150-200A continuous<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Aluminum (Budget Option):<\/strong><\/p>\n\n\n\n
Advantages:\n- Lower cost ($10-20 per busbar)\n- Lighter weight (1\/3 of copper)<\/code><\/pre>\n\n\n\n
Disadvantages: – Higher resistance (2.82 \u00d7 10\u207b\u2078 \u03a9\u00b7m) – Requires larger cross-section for same ampacity – Oxidation requires anti-oxidant compound – Special crimping required (not solder-compatible)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Typical sizing for 4-string combiner: – 1\/4″ thick \u00d7 3″ wide \u00d7 12″ long (larger than copper) – Ampacity: 150-200A continuous<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Busbar Resistance Calculation:<\/strong><\/p>\n\n\n\n
Formula: R = \u03c1 \u00d7 L \/ A<\/code><\/pre>\n\n\n\n
Where: R = resistance (\u03a9) \u03c1 = resistivity (\u03a9\u00b7m) L = length (m) A = cross-sectional area (m\u00b2)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Example: Copper busbar 12″ long, 1\/4″ \u00d7 2″ L = 0.3048 m (12 inches) A = 0.00635 m \u00d7 0.0508 m = 0.000323 m\u00b2 \u03c1 = 1.68 \u00d7 10\u207b\u2078 \u03a9\u00b7m<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
R = (1.68 \u00d7 10\u207b\u2078 \u00d7 0.3048) \/ 0.000323 R = 0.0000159 \u03a9 (15.9 microohms)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
At 40A total current: Voltage drop = 40A \u00d7 0.0000159\u03a9 = 0.00064V (negligible) Power loss = 40\u00b2 \u00d7 0.0000159\u03a9 = 0.025W (minimal heat)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Enclosure Selection for Solar Environments<\/h3>\n\n\n\n
NEMA Rating Requirements:<\/strong><\/p>\n\n\n\n
Rooftop Installation:\n- Minimum: NEMA 3R (rainproof)\n- Better: NEMA 4 (waterproof, hose-directed water)\n- Best: NEMA 4X (waterproof + corrosion-resistant)<\/code><\/pre>\n\n\n\n
Ground-Mount Installation: – Minimum: NEMA 4 (splash\/spray protection) – Better: NEMA 4X stainless steel (long-term durability)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Coastal\/Marine Environments: – Required: NEMA 4X with 316 stainless steel – Reason: Salt spray causes rapid corrosion of standard enclosures<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Material Selection:<\/strong><\/p>\n\n\n\n
Powder-Coated Steel (NEMA 3R):\n- Cost: $80-150 for 12\u00d716\" combiner box\n- Lifespan: 10-15 years\n- Best for: Dry climates, protected mounting locations<\/code><\/pre>\n\n\n\n
Aluminum (NEMA 4): – Cost: $150-250 – Lifespan: 15-20 years – Best for: General outdoor use, moderate climates<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
304 Stainless Steel (NEMA 4X): – Cost: $300-500 – Lifespan: 20-30 years – Best for: Harsh environments, coastal areas (not direct saltwater)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
316 Stainless Steel (NEMA 4X): – Cost: $500-800 – Lifespan: 30-40 years – Best for: Direct saltwater exposure, tropical marine environments<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Thermal Management:<\/strong><\/p>\n\n\n\n
Solar fuse panels generate heat from:
1. Fuse internal resistance (I\u00b2R losses)
2. Busbar resistance
3. Connection resistance
4. Solar heating (black roof, 70\u00b0C ambient)<\/p>\n\n\n\n
Ventilation Requirements:\n- Passive vents: Top and bottom (25 sq in each minimum)\n- Vent design: Labyrinth-style (prevents rain entry)\n- Screen mesh: Insect\/rodent protection\n- Positioning: Fuse panel vertical (not horizontal) for convection<\/code><\/pre>\n\n\n\n
Active cooling (if needed): – 12V DC fan (10-15 CFM) – Thermostat-controlled (activates at 50\u00b0C) – Solar-powered option for off-grid installations<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Installation Procedures and Best Practices<\/h2>\n\n\n\n
Location Selection and Mounting<\/h3>\n\n\n\n
NEC 690.31(C) – Accessible Location Requirements:<\/strong><\/p>\n\n\n\n
Combiner\/fuse panel must be:\n- Readily accessible (no ladder required for operation)\n- Near array but not in direct shadow path\n- Within sight of array (visual confirmation of isolation)\n- Protected from mechanical damage\n- Minimum 3 feet from any opening (windows, vents)\n<\/code><\/pre>\n\n\n\n
Optimal Mounting Locations:<\/strong><\/p>\n\n\n\n
Rooftop Installations:<\/strong><\/p>\n\n\n\n
Preferred:\n- North side of roof peak (shaded, cooler)\n- Under eave overhang (rain protection)\n- Near main service panel (shorter wire runs)<\/code><\/pre>\n\n\n\n
Avoid: – Direct south-facing (excessive heat) – Low roof areas (flooding, debris accumulation) – Under trees (falling branches, debris)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Ground-Mount Installations:<\/strong><\/p>\n\n\n\n
Preferred:\n- Elevated pedestal (18-24\" above grade)\n- Concrete pad foundation (prevents settling)\n- Near array edge (shorter string wiring)<\/code><\/pre>\n\n\n\n
Avoid: – Low-lying areas (flooding risk) – Direct soil contact (moisture, corrosion) – Under array panels (difficult access)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Mounting Hardware:<\/strong><\/p>\n\n\n\n
Rooftop Mounting (on structural surface):\n- Use 1\/4\" \u00d7 3\" lag bolts\n- Pre-drill pilot holes (3\/16\" for 1\/4\" bolt)\n- Penetrate through roof membrane using proper flashing\n- Seal all penetrations with butyl tape + sealant\n- Use backing plate if mounting to single rafter<\/code><\/pre>\n\n\n\n
Ground Pedestal Mounting: – Pour 12″ \u00d7 12″ \u00d7 12″ concrete footing – Embed 1\/2″ J-bolts in wet concrete (4 bolts) – Allow 7 days curing before loading – Use stainless steel hardware (corrosion resistance)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
String Wire Termination Methods<\/h3>\n\n\n\n
Proper Lug Selection:<\/strong><\/p>\n\n\n\n
Wire Size: 10 AWG (typical for 10-15A strings)\nRequired Lug: Copper compression lug, ring terminal\nSizing: 10 AWG wire \u2192 Yellow compression lug\nBolt hole: 1\/4\" or 5\/16\" (match busbar stud)<\/code><\/pre>\n\n\n\n
Incorrect lugs to avoid: – Crimp-on spade terminals (vibration-prone) – Solder terminals (heat failure in sun) – Barrel lugs (poor contact area)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Crimping Procedure:<\/strong><\/p>\n\n\n\n
Step 1: Strip wire insulation\n- Length: 3\/8\" to 1\/2\" (match lug barrel length)\n- Use wire stripper (not knife - prevents nicking)\n- Inspect strands for damage<\/code><\/pre>\n\n\n\n
Step 2: Insert wire into lug – Strands fully inserted (no exposed copper outside barrel) – Wire insulation butts against lug shoulder<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 3: Crimp lug – Use hydraulic compression crimper (not pliers!) – Crimp in center of barrel (not ends) – Apply full pressure (ratcheting crimper ensures complete crimp)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 4: Tug test – Pull wire with 30-40 lbs force – Wire should not pull out of lug – If fails: Discard and re-crimp with new lug<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 5: Heat shrink – Slide heat shrink over crimped lug – Heat with heat gun (not lighter – uneven heating) – Shrink fully to create weather seal<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Busbar Connection:<\/strong><\/p>\n\n\n\n
Torque Specifications:\n- 1\/4\" busbar stud: 80-100 in-lbs\n- 5\/16\" busbar stud: 120-150 in-lbs\n- 3\/8\" busbar stud: 180-220 in-lbs<\/code><\/pre>\n\n\n\n
Connection sequence: 1. Place lug on busbar stud 2. Install split-lock washer (prevents loosening) 3. Install flat washer (distributes load) 4. Thread nut onto stud 5. Torque in stages: 50% \u2192 75% \u2192 100% 6. Verify no movement after torquing 7. Mark with torque seal paint (visual inspection indicator)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Polarity Management:<\/strong><\/p>\n\n\n\n
Critical: Positive and negative must not be reversed!<\/p>\n\n\n\n
Labeling System:\n- RED heat shrink: Positive (+) conductors\n- BLACK heat shrink: Negative (-) conductors\n- Wire labels: \"String 1+\", \"String 1-\", etc.\n- Busbar labels: \"POSITIVE BUS\", \"NEGATIVE BUS\"<\/code><\/pre>\n\n\n\n
Physical separation: – Minimum 1.5″ spacing between positive and negative busbars – Use insulating barrier if closer spacing required – Color-code busbars: Red positive, Black negative<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Verification before energizing: – Use multimeter to verify polarity at each connection – Measure string Voc with meter (verify expected voltage) – Check polarity at output terminals before connecting inverter<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Grounding and Bonding Procedures<\/h3>\n\n\n\n
Equipment Grounding (NEC 690.43):<\/strong><\/p>\n\n\n\n
All metal enclosures and frames must be grounded:<\/p>\n\n\n\n
Grounding Electrode Conductor Sizing (NEC Table 250.122):<\/code><\/pre>\n\n\n\n
System Maximum Overcurrent Device \u2192 Minimum Ground Wire 15A fuses \u2192 14 AWG 20A fuses \u2192 12 AWG 30A fuses \u2192 10 AWG 60A fuses \u2192 10 AWG 100A fuses \u2192 8 AWG 200A fuses \u2192 6 AWG<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Installation Procedure:<\/strong><\/p>\n\n\n\n
Step 1: Ground busbar installation\n- Mount copper ground busbar inside enclosure\n- Use 6 AWG minimum conductor\n- Minimum 4 connection points for string grounds<\/code><\/pre>\n\n\n\n
Step 2: Enclosure bonding – Green bonding screw threads into enclosure back – Connects ground busbar to enclosure metal – Ensures enclosure at ground potential<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 3: Array frame grounding – Run grounding electrode conductor from ground busbar to array frame – Use listed grounding clamps (not self-tapping screws) – Bond each solar panel frame to grounding system<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 4: System grounding electrode – Connect to existing building ground (preferred) – Or install dedicated ground rod (8 ft \u00d7 5\/8″ copper-clad minimum) – Drive rod to full depth (only 1-2″ exposed) – Use approved ground rod clamp<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 5: Grounding verification – Measure resistance from enclosure to ground: Should be <1\u03a9 – Measure resistance from array frame to ground: Should be <1\u03a9 – If >1\u03a9: Check connections, clean bonding surfaces, verify ground rod integrity<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Ground Fault Protection:<\/strong><\/p>\n\n\n\n
For ungrounded PV systems (most residential):\n- Ground fault protection device (GFPD) required per NEC 690.41(B)\n- Typically integrated in inverter\n- Fuse panel grounding ensures chassis protection only\n- GFPD detects current leakage to ground (30-300mA threshold)\n<\/code><\/pre>\n\n\n\n
\"Solar<\/figure>\n\n\n\n
Testing and Commissioning Procedures<\/h2>\n\n\n\n
Pre-Energization Testing<\/h3>\n\n\n\n
Visual Inspection Checklist:<\/strong><\/p>\n\n\n\n
Enclosure:\n\u2610 Securely mounted (no movement when pushed)\n\u2610 Gaskets intact (no gaps in seal)\n\u2610 Drainage holes at bottom (outdoor installations)\n\u2610 No visible damage or corrosion\n\u2610 Door opens\/closes smoothly with proper latch<\/code><\/pre>\n\n\n\n
Internal Components: \u2610 All fuses proper rating and type (gPV-rated) \u2610 Fuses seated fully in holders \u2610 Busbars straight, no bends or cracks \u2610 All connections tight (visual verification of torque seals) \u2610 No exposed conductors (heat shrink intact) \u2610 Labels present and legible on all circuits<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Wiring: \u2610 Correct wire gauge for ampacity \u2610 Proper polarity (red\/black color coding) \u2610 No damaged insulation \u2610 Wire support every 18″ (prevents sagging) \u2610 Proper bend radius maintained (10\u00d7 wire diameter minimum)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Continuity and Insulation Testing:<\/strong><\/p>\n\n\n\n
Test 1: Continuity (All Fuses Installed)\nEquipment: Digital multimeter (resistance mode)<\/code><\/pre>\n\n\n\n
Procedure: 1. Disconnect array and inverter (de-energize completely) 2. Set meter to 200\u03a9 range 3. Measure string positive to output positive: Should be <0.1\u03a9 per string 4. Measure string negative to output negative: Should be <0.1\u03a9 5. If >1\u03a9: Check fuse installation, tighten connections<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Test 2: Insulation Resistance (Megger Test) Equipment: 500V DC megohmmeter<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Procedure: 1. Remove all fuses temporarily 2. Separate positive and negative busbars (disconnect jumpers if present) 3. Connect megger between positive busbar and ground 4. Apply 500V DC for 60 seconds 5. Reading should be >1M\u03a9 (preferably >10M\u03a9) 6. Repeat test: negative busbar to ground 7. If <1M\u03a9: Moisture in enclosure or insulation damage<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Test 3: Polarity Verification Equipment: Digital multimeter (voltage mode)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Procedure: 1. Reinstall all fuses 2. Disconnect inverter (output open) 3. Measure each string voltage at fuse holder: – Positive to negative: Should equal string Voc (390-440V typical) – Positive to ground: Should be half of Voc (ungrounded system) or full Voc (negative grounded) – Negative to ground: Should be half of Voc (ungrounded) or 0V (negative grounded) 4. Verify polarity correct before proceeding<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Energization and Load Testing<\/h3>\n\n\n\n
Initial Energization Sequence:<\/strong><\/p>\n\n\n\n
Step 1: String-by-String Energization\n1. Ensure inverter still disconnected\n2. Install String 1 fuse only\n3. Measure voltage at output busbar (should equal String 1 Voc)\n4. Remove String 1 fuse\n5. Install String 2 fuse only\n6. Measure voltage (should equal String 2 Voc, within 5% of String 1)\n7. Repeat for all strings individually\n8. Verify all strings produce similar voltage (within 10% variance)<\/code><\/pre>\n\n\n\n
Purpose: Detect miswired strings before parallel operation<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 2: All Strings Paralleled 1. Install all string fuses 2. Measure output voltage (should equal individual string Voc) 3. Measure current with DC clamp meter (should be sum of all string Isc) 4. Example: 4 strings \u00d7 10.5A = 42A maximum 5. Verify current within expected range (sunlight intensity dependent)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 3: Connect Inverter 1. Install output fuse 2. Connect output cables to inverter DC input terminals 3. Verify inverter polarity indicator (green LED or display) 4. If polarity error indicated: STOP, reverse connections 5. Energize inverter per manufacturer instructions 6. Verify inverter operation (converts DC to AC, feeds grid)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Performance Verification:<\/strong><\/p>\n\n\n\n
Test Under Full Sun Conditions:\n1. Check time of day: 10 AM - 2 PM optimal (sun angle)\n2. Clear weather required (no clouds)\n3. Measure irradiance with pyranometer: Should be >800 W\/m\u00b2<\/code><\/pre>\n\n\n\n
String Current Testing: 1. Use DC clamp meter on each string positive conductor (before fuse) 2. Current should be within 90-110% of rated Isc 3. Example: Rated Isc 10.5A \u2192 Expect 9.5-11.5A 4. If <90%: Shading, soiling, or panel degradation 5. If >110%: Measurement error or irradiance >1000 W\/m\u00b2<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
String Voltage Testing: 1. Measure each string voltage at fuse terminals 2. Should be lower than Voc (inverter loading) 3. Typical: 350-400V under load (vs 400-440V Voc) 4. All strings should be within 5% of each other 5. If one string significantly lower: Check connections or panel issues<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Thermal Testing: 1. Operate at full power for 1 hour 2. Use infrared thermometer or thermal camera 3. Measure temperature of: – Fuse bodies: Should be <50\u00b0C above ambient – Busbar connections: Should be <30\u00b0C above ambient – Wire terminations: Should be <40\u00b0C above ambient 4. If any component >70\u00b0C above ambient: Investigate high resistance connection<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
\"Solar<\/figure>\n\n\n\n
Maintenance and Troubleshooting<\/h2>\n\n\n\n
Preventive Maintenance Schedule<\/h3>\n\n\n\n
Quarterly Inspection (Every 3 Months):<\/strong><\/p>\n\n\n\n
Visual Inspection:\n- Check enclosure for water infiltration (staining, rust)\n- Verify gasket seal intact (no gaps, cracks, or hardening)\n- Inspect fuse holders for discoloration (overheating indicator)\n- Check wire insulation for UV damage (cracking, brittleness)\n- Verify no insect\/rodent nests inside enclosure<\/code><\/pre>\n\n\n\n
Thermal Scan: – Use infrared thermometer on sunny day at solar noon – Measure each fuse body temperature – Should be <40\u00b0C above ambient under full load – If >50\u00b0C: Check connection integrity<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Performance Check: – Measure each string current with clamp meter – Compare to baseline (commissioning data) – Variation >10% indicates potential issue<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Annual Comprehensive Service:<\/strong><\/p>\n\n\n\n
Electrical Testing:\n- Insulation resistance test (megger): Should remain >1M\u03a9\n- Ground continuity test: Should remain <1\u03a9\n- String voltage balance check: Within 5% across all strings\n- Torque verification: Re-torque all connections to specification<\/code><\/pre>\n\n\n\n
Physical Inspection: – Check busbar integrity (no corrosion or oxidation) – Inspect fuse contacts for pitting or wear – Clean ventilation screens (remove dust, debris) – Verify drainage holes clear (outdoor panels) – Test door latch and hinge operation<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Documentation: – Record all measurements in maintenance log – Compare to baseline and previous inspections – Photograph any anomalies for trending – Update system one-line diagram if changes made<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Common Problems and Solutions<\/h3>\n\n\n\n
Problem 1: Individual String Fuse Blowing Repeatedly<\/strong><\/p>\n\n\n\n
Symptoms:<\/strong>
– One specific string fuse blows within hours\/days
– Other strings operate normally
– Fuse replacement solves temporarily but re-occurs<\/p>\n\n\n\n
Diagnostic Steps:<\/strong><\/p>\n\n\n\n
Step 1: Measure String Voltage (Fuse Removed)\n- Disconnect string at fuse panel\n- Measure string Voc with multimeter\n- Should be 390-440V typical (8-panel string)\n- If significantly low or zero: Internal string problem<\/code><\/pre>\n\n\n\n
Step 2: Measure String Resistance – Disconnect both positive and negative – Measure resistance positive to negative – Should be >100k\u03a9 (essentially infinite when not in sun) – If <1k\u03a9: Short circuit in string (damaged panel or wire)<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 3: Inspect String Wiring – Visual inspection of all string cables – Look for damaged insulation, animal chewing, pinch points – Check wire routing (excessive heat exposure, UV damage) – Verify no wires touching sharp edges or moving parts<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 4: Test Individual Panels – Disconnect string at first panel – Measure Voc of first panel only: Should be 45-50V – If good, reconnect and test next panel – Continue until faulty panel identified – Replace panel if shorted internally<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Common Causes:<\/strong>
1. Panel internal short circuit (cell or junction box failure)
2. Damaged wire insulation (chewing by squirrels\/rats common)
3. Water infiltration into junction box
4. Physical damage during roof work or cleaning
5. Manufacturing defect in panel<\/p>\n\n\n\n
Solution:<\/strong>
– Isolate and bypass faulty panel (temporary)
– Replace damaged panel (permanent)
– Repair\/replace damaged wiring
– Add rodent guards if animal damage detected<\/p>\n\n\n\n
Problem 2: Low Output Current on All Strings<\/strong><\/p>\n\n\n\n
Symptoms:<\/strong>
– All strings producing <90% expected current – System power output reduced proportionally – Problem affects entire array uniformly Diagnostic Steps:<\/strong><\/p>\n\n\n\n
Step 1: Check Irradiance\n- Measure solar irradiance with pyranometer\n- If <800 W\/m\u00b2: Low sun angle, clouds, or haze (normal)\n- Only diagnose issues when irradiance >900 W\/m\u00b2<\/code><\/pre>\n\n\n\n
Step 2: Inspect Array for Soiling – Visual inspection of panel surfaces – Dust, pollen, bird droppings, leaves – Even thin film reduces output 5-20% – Clean panels with water and soft brush<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 3: Check for Partial Shading – Walk array during problem time of day – Look for shadows from trees, buildings, equipment – Even small shadow on one panel affects entire string – Trim trees or relocate shading objects<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 4: Verify Inverter Operation – Check inverter for derating due to high temperature – Inverters reduce power output above 40\u00b0C ambient – Improve ventilation or add cooling if needed<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Step 5: Measure String Voltage Under Load – Should be 320-380V when inverter operating – If lower: Check for high resistance connections – Voltage drop indicates power loss<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Common Causes:<\/strong>
1. Soiling (dust, pollen, bird droppings) – Most common
2. Partial shading from vegetation growth
3. Panel degradation (normal 0.5-1% per year)
4. Inverter thermal derating
5. Loose connections (high resistance losses)<\/p>\n\n\n\n
Solution:<\/strong>
– Implement cleaning schedule (semi-annual minimum)
– Trim vegetation to eliminate shading
– Accept normal degradation (<1% per year) – Improve inverter cooling – Re-torque all connections Problem 3: Corrosion in Fuse Panel Enclosure<\/strong><\/p>\n\n\n\n
Symptoms:<\/strong>
– White or green powder on busbars
– Rust on mounting hardware
– Loose connections due to terminal corrosion
– Water staining inside enclosure<\/p>\n\n\n\n
Causes:<\/strong>
– Damaged gasket allowing moisture entry
– Condensation from temperature cycling
– Coastal\/marine salt spray
– Missing or blocked drainage holes<\/p>\n\n\n\n
Preventive Measures:<\/strong><\/p>\n\n\n\n
For New Installations:\n- Use NEMA 4X stainless steel in coastal areas\n- Apply corrosion-inhibiting compound on all copper connections:\n  - Noalox (aluminum)\n  - DeoxIT Gold (copper\/brass)\n  - Boeshield T-9 (general protection)\n- Install desiccant packs inside enclosure (replace annually)\n- Use stainless steel hardware throughout<\/code><\/pre>\n\n\n\n
For Existing Installations Showing Corrosion: 1. Power down completely 2. Remove all fuses and disconnect wiring 3. Clean affected areas: – Wire brush for heavy corrosion – Scotch-Brite pad for light oxidation – Contact cleaner spray 4. Apply protective coatings 5. Replace damaged gaskets 6. Verify drainage holes clear and positioned correctly 7. Consider upgrading to higher-rated enclosure<\/p>\n\n\n\n
<\/code><\/pre>\n\n\n\n
Manufacturer Recommendations and Product Selection<\/h2>\n\n\n\n
Combiner Box Manufacturers (Complete Systems)<\/h3>\n\n\n\n
Midnite Solar MNPV Combiner Series<\/strong>
– Price<\/strong>: $200-600 (depending on string count)
– Features<\/strong>: Pre-wired busbars, DIN-rail fuse holders, NEMA 3R
– Configurations<\/strong>: 2-16 string options
– Best For<\/strong>: Residential and small commercial (<10kW) Solectria PV Combiners<\/strong>
– Price<\/strong>: $400-1200
– Features<\/strong>: Surge protection integrated, monitoring capabilities
– Configurations<\/strong>: 6-18 string capacity
– Best For<\/strong>: Commercial solar (10-50kW)<\/p>\n\n\n\n
SolarBOS Combiners<\/strong>
– Price<\/strong>: $300-800
– Features<\/strong>: Rapid shutdown integration, arc-fault detection
– Configurations<\/strong>: 4-12 string
– Best For<\/strong>: Residential with rapid shutdown requirements<\/p>\n\n\n\n
Individual Component Suppliers<\/h3>\n\n\n\n
gPV Fuses:<\/strong>
– Mersen (formerly Ferraz Shawmut)<\/strong>: $10-20 per fuse, gold standard
– Littelfuse<\/strong>: $8-15 per fuse, excellent reliability
– Eaton Bussmann<\/strong>: $10-18 per fuse, widely available<\/p>\n\n\n\n
Busbars:<\/strong>
– Ilsco<\/strong>: Copper busbars with pre-drilled holes, $30-60
– Panduit<\/strong>: Tin-plated copper, corrosion-resistant, $40-80
– TE Connectivity<\/strong>: High-ampacity busbars, $50-100<\/p>\n\n\n\n
Enclosures:<\/strong>
– Hoffman<\/strong>: NEMA 4X stainless, premium quality, $400-1000
– Hammond<\/strong>: NEMA 3R\/4 powder-coated, mid-range, $150-400
– BUD Industries<\/strong>: NEMA 3R budget, basic protection, $80-200<\/p>\n\n\n\n
Frequently Asked Questions<\/h2>\n\n\n\n
1. Can I install a solar fuse panel myself or do I need a licensed electrician?<\/strong><\/p>\n\n\n\n
Regulations vary by jurisdiction. In most US states, a licensed electrician or solar installer certification is required for grid-tied systems due to NEC 690 complexity and utility interconnection requirements. DIY installation may be permitted for off-grid systems in some areas. However, improper installation creates fire and electrocution hazards\u2014professional installation strongly recommended. Permitting and inspection also typically required, which assumes licensed contractor involvement. Check local building department requirements before proceeding.<\/p>\n\n\n\n
2. What’s the difference between a combiner box and a solar fuse panel?<\/strong><\/p>\n\n\n\n
These terms are synonymous in residential solar\u2014both refer to the enclosure that combines multiple PV strings with individual overcurrent protection. “Combiner box” emphasizes the combining function (parallel strings), while “fuse panel” emphasizes the protection function (fuses for each string). Some define combiner as fuse-only (no disconnect) and fuse panel as including disconnect capability, but this distinction isn’t standardized. Functionally identical for residential installations.<\/p>\n\n\n\n
3. Why do solar fuses need to be gPV-rated instead of standard DC fuses?<\/strong><\/p>\n\n\n\n
gPV-rated fuses are specifically tested for photovoltaic reverse current interruption and high-temperature operation. Solar arrays present unique challenges: reverse current from other strings during faults, rooftop temperatures exceeding 70\u00b0C, and 25-year outdoor UV exposure. Standard DC fuses aren’t tested for reverse current (may fail catastrophically), have lower temperature ratings (nuisance blowing), and lack UV-resistant construction. NEC 690 and UL standards require gPV rating for code compliance. Using non-gPV fuses voids insurance and creates fire hazards.<\/p>\n\n\n\n
4. How do I size the output fuse for the combined strings?<\/strong><\/p>\n\n\n\n
Calculate total short-circuit current (sum all string Isc values), then apply 125% continuous load factor per NEC 690.8(B). Example: 4 strings \u00d7 10.5A Isc = 42A total, \u00d7 1.25 = 52.5A minimum. Select next standard fuse size: 60A. Wire must be sized for fuse rating (60A requires 6 AWG minimum). Some systems omit output fuse if inverter has adequate internal protection and wire sizing allows\u2014verify with inverter manufacturer and AHJ (authority having jurisdiction).<\/p>\n\n\n\n
5. Can I install the fuse panel horizontally or does it need to be vertical?<\/strong><\/p>\n\n\n\n
Vertical orientation strongly preferred for thermal management\u2014heat rises naturally, creating convection cooling through top vents. Horizontal mounting traps heat and reduces fuse life. If horizontal mounting unavoidable, use forced-air cooling (fan) and derate fuse capacity 10-15%. Some fuse holders are orientation-specific (gravity-retained fuses must be vertical). Check manufacturer specifications. For NEMA 3R\/4 enclosures, vertical orientation also improves water drainage and prevents pooling.<\/p>\n\n\n\n
6. How often should I replace fuses in a solar fuse panel?<\/strong><\/p>\n\n\n\n
Fuses don’t require routine replacement if properly sized\u2014they should last system lifetime (20-25 years) without operating. Replace immediately after any blow event. Preventive replacement not needed unless: thermal imaging shows sustained overheating (>60\u00b0C above ambient), visible discoloration\/corrosion, or fuse holder damage. Annual inspection recommended but replacement only if defects found. Carrying spare fuses (2\u00d7 each rating) recommended for rapid replacement after fault events to minimize downtime.<\/p>\n\n\n\n
7. What causes condensation inside a solar fuse panel and how do I prevent it?<\/strong><\/p>\n\n\n\n
Temperature cycling (hot day, cool night) causes air inside sealed enclosure to contract, drawing in humid air through micro-gaps. When interior cools below dew point, moisture condenses on metal surfaces. Prevention: (1) Use breather vents with desiccant in sealed enclosures, (2) Apply conformal coating to busbars, (3) Install desiccant packs (replace annually), (4) Ensure drainage holes at bottom, (5) Locate enclosure in temperature-stable area (avoid direct sun). Coastal installations especially prone\u2014consider NEMA 4X with better sealing.<\/p>\n\n\n\n
Conclusion: Professional Solar Fuse<\/a> Panel Installation<\/h2>\n\n\n\n
A properly installed solar fuse panel provides reliable string-level overcurrent protection and isolation for decades of photovoltaic system operation. Following NEC 690 sizing requirements, using gPV-rated components, and implementing professional wiring techniques ensures code-compliant, safe, and efficient solar array protection.<\/p>\n\n\n\n
Installation Summary Checklist:<\/strong><\/p>\n\n\n\n
Pre-Installation:<\/strong>
– [ ] Calculate fuse sizes per NEC<\/a> 690.9 (String Isc \u00d7 1.56)
– [ ] Select gPV-rated fuses with 600V DC minimum rating
– [ ] Determine enclosure NEMA rating for environment
– [ ] Plan location meeting NEC 690.31 accessibility requirements
– [ ] Obtain proper permits and schedule inspections<\/p>\n\n\n\n
Mechanical Installation:<\/strong>
– [ ] Mount enclosure securely to structural surface
– [ ] Verify level and plumb orientation (vertical preferred)
– [ ] Install copper busbars with proper standoffs
– [ ] Mount fuse holders with correct spacing (1.5″ minimum)
– [ ] Ensure ventilation adequate for thermal management<\/p>\n\n\n\n
Electrical Installation:<\/strong>
– [ ] Terminate all conductors with compression lugs (not crimp-on)
– [ ] Torque all connections to specification (mark with paint)
– [ ] Maintain correct polarity (red positive, black negative)
– [ ] Install complete grounding system (<1\u03a9 resistance verified) – [ ] Label all circuits clearly (string ID, voltage, current) Testing and Commissioning:<\/strong>
– [ ] Perform continuity test (all paths <0.1\u03a9) – [ ] Insulation resistance test (>1M\u03a9 to ground)
– [ ] Verify polarity before energizing
– [ ] Test strings individually before parallel operation
– [ ] Thermal scan after 1 hour full-sun operation (<70\u00b0C rise) Maintenance Schedule:<\/strong>
– [ ] Quarterly visual inspection and thermal scan
– [ ] Annual comprehensive testing and torque check
– [ ] Clean panels semi-annually (affects fuse panel loading)
– [ ] Replace gaskets every 5 years (prevent moisture)
– [ ] Keep spare fuses on-site (2\u00d7 each rating)<\/p>\n\n\n\n
Critical Safety Reminders:<\/strong>
– Always use gPV-rated fuses (standard DC fuses unsafe)
– Verify wire ampacity exceeds fuse rating (fire prevention)
– Maintain proper polarity (reversed connections damage equipment)
– Ground all metal enclosures per NEC 690.43
– Work during daylight only (array cannot be de-energized)
– Use insulated tools rated for voltage (600V+)<\/p>\n\n\n\n
Investment Perspective:<\/strong><\/p>\n\n\n\n
A quality solar fuse panel installation ($500-1500 installed) protects $10,000-50,000 of solar array investment. Cutting corners on components (non-gPV fuses, undersized wire, improper enclosure) or installation quality creates fire hazards, insurance voids, and premature system failure. Professional installation with code-compliant materials ensures 25+ years of reliable protection and full warranty coverage.<\/p>\n\n\n\n
The fuse panel is a critical safety component\u2014visible evidence of installation quality and engineering competence. A well-designed, properly installed combiner demonstrates professional solar installation and provides peace of mind for decades of clean energy production.<\/p>\n\n\n\n
\n
Frequently Asked Questions<\/h2>\n
\n
Can I install a solar fuse panel myself or do I need a licensed electrician?<\/h3>\n
\n
Regulations vary by jurisdiction. In most US states, a licensed electrician or solar installer certification is required for grid-tied systems due to NEC 690 complexity. DIY may be permitted for off-grid in some areas. Professional installation strongly recommended due to fire and electrocution hazards. Check local building department requirements.<\/p>\n<\/div>\n<\/div>\n
\n
What’s the difference between a combiner box and a solar fuse panel?<\/h3>\n
\n
These terms are synonymous in residential solar\u2014both refer to the enclosure that combines multiple PV strings with individual overcurrent protection. ‘Combiner box’ emphasizes combining function (parallel strings), while ‘fuse panel’ emphasizes protection function. Functionally identical for residential installations.<\/p>\n<\/div>\n<\/div>\n
\n
Why do solar fuses need to be gPV-rated instead of standard DC fuses?<\/h3>\n
\n
gPV-rated fuses are specifically tested for photovoltaic reverse current interruption and high-temperature operation. Solar arrays present unique challenges: reverse current from other strings, rooftop temperatures exceeding 70\u00b0C, and 25-year outdoor UV exposure. Standard DC fuses aren’t tested for reverse current and may fail catastrophically. NEC 690 requires gPV rating.<\/p>\n<\/div>\n<\/div>\n
\n
How do I size the output fuse for the combined strings?<\/h3>\n
\n
Calculate total short-circuit current (sum all string Isc values), then apply 125% continuous load factor per NEC 690.8(B). Example: 4 strings \u00d7 10.5A Isc = 42A total, \u00d7 1.25 = 52.5A minimum. Select next standard fuse size: 60A. Wire must be sized for fuse rating (60A requires 6 AWG minimum).<\/p>\n<\/div>\n<\/div>\n
\n
Can I install the fuse panel horizontally or does it need to be vertical?<\/h3>\n
\n
Vertical orientation strongly preferred for thermal management\u2014heat rises naturally, creating convection cooling. Horizontal mounting traps heat and reduces fuse life. If horizontal mounting unavoidable, use forced-air cooling and derate fuse capacity 10-15%. Vertical orientation also improves water drainage in outdoor enclosures.<\/p>\n<\/div>\n<\/div>\n
\n
How often should I replace fuses in a solar fuse panel?<\/h3>\n
\n
Fuses don’t require routine replacement if properly sized\u2014they should last system lifetime (20-25 years) without operating. Replace immediately after any blow event. Annual inspection recommended but replacement only if defects found. Carry spare fuses (2\u00d7 each rating) for rapid replacement after fault events.<\/p>\n<\/div>\n<\/div>\n
\n
What causes condensation inside a solar fuse panel and how do I prevent it?<\/h3>\n
\n
Temperature cycling (hot day, cool night) causes air contraction, drawing in humid air. Prevention: use breather vents with desiccant, apply conformal coating to busbars, install desiccant packs (replace annually), ensure drainage holes, locate in temperature-stable area. Coastal installations especially prone\u2014consider NEMA 4X.<\/p>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
Introduction: Essential PV Array Protection Infrastructure A solar fuse panel (also called a PV combiner box) consolidates multiple solar array strings into a single output while providing individual overcurrent protection for each string. This critical component prevents reverse current damage, enables string-level isolation, and ensures NEC-compliant installation for residential and commercial photovoltaic systems. This comprehensive […]<\/p>\n","protected":false},"author":1,"featured_media":2117,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36],"tags":[],"class_list":["post-2121","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dc-circuit-breaker-blog"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/posts\/2121","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/comments?post=2121"}],"version-history":[{"count":1,"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/posts\/2121\/revisions"}],"predecessor-version":[{"id":2187,"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/posts\/2121\/revisions\/2187"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/media\/2117"}],"wp:attachment":[{"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/media?parent=2121"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/categories?post=2121"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sinobreaker.com\/ko\/wp-json\/wp\/v2\/tags?post=2121"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}