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Configure solarSolar Panel Not Working? Malaysia Troubleshooting Guide 2026
Your solar system should silently save you about RM140–960 a month, depending on system size. If it isn't — whether you're seeing low output, error codes, or unexpected bills — this guide covers every common failure mode in Malaysia's climate. Most issues can be narrowed down in minutes.
Varies by site
Output lost from dirty panels
DC + AC
Surge protection (SPD) on both sides
20-40%
Normal monsoon output drop
Diagnose Your Problem
Answer 2-3 questions to get Malaysia-specific troubleshooting steps.
Interactive Solar Diagnostic
Answer 2-3 questions to get your fix
What symptom is your system showing?
Monsoon Season: Normal vs Abnormal Output
Malaysia has two distinct monsoon seasons. Knowing what is normal prevents unnecessary service calls.
Normal — Do Not Panic
- •Output can drop by an estimated 20-40% during heavy rain ✓
- •Overcast sky can cut generation by an estimated 40-60% ✓
- •Short rainy bursts: output bounces back within minutes ✓
- •East coast monsoon: Oct-Mar, expect lower months ✓
- •West coast monsoon: May-Sep, prepare for dips ✓
- •Panels still generate power on cloudy days ✓
Abnormal — Investigate
- •Output drops more than 50% on a sunny day ✗
- •System shows zero output on a partly sunny day ✗
- •Performance worse than same month last year by 10%+ ✗
- •Inverter showing error codes during rain ✗
- •One string producing half of what other strings produce ✗
- •Output does not recover after rain ends ✗
Average Monthly Irradiance — Kuala Lumpur
Source: NASA POWER / Solargis. Daily average peak sun hours.
Heat Derating: Malaysia's Hidden Output Killer
Every 1°C above 25°C cuts panel output by the temperature coefficient (a fraction of a percent per °C; see the datasheet). Malaysian rooftops reach 60-70°C on sunny days.
Temperature Coefficient Comparison
LONGi Hi-MO X6 (market reference)
See LONGi datasheet
Jinko Tiger Neo
-0.30%/°C
Trina Vertex S+
-0.30%/°C
Budget PERC panels
-0.40-0.47%/°C
Malaysia Rooftop Reality
Rooftop surface temperature: 55-70°C on a sunny afternoon
A panel rated 400W at 25°C produces only 340-370W at 60°C rooftop temp
Good roof ventilation gap (10-15cm) reduces panel temp by 5-8°C
N-type TOPCon panels (Jinko, Trina) can outperform PERC by an estimated 3-5% in Malaysian heat (check datasheet temperature coefficients)
Shading: The Silent Performance Killer
Malaysia's fast-growing tropical vegetation means shading problems can develop within one rainy season.
How to Check
Take a photo of your roof from the same angle at 10am, 12pm, and 2pm. Compare to a photo from 1 year ago. Any new shadows?
The String Problem
In a string inverter, one shaded panel drags down the entire string. Shading even one panel can cut a string's output noticeably.
Solutions
Panel-level optimizers (RM500-2,000 retrofit) or micro-inverters (Enphase IQ8) eliminate string losses. Prune trees if possible.
Malaysia-specific: Angsana, Raintree, and Tembusu trees are common culprits. Growth rate of 1-2m/year means a system installed with clear sky in 2022 may have significant shading by 2026.
Inverter Error Code Reference
Common error codes across top brands installed in Malaysia, with Malaysia-specific context.
| Brand | Error | Meaning | Action | Level |
|---|---|---|---|---|
| Huawei | — | Grid over-voltage — TNB voltage spike | Often clears when grid voltage normalises. If daily, report to TNB 15454 | Monitor |
| Huawei | — | DC arc fault detected — FIRE RISK | Shut off immediately. Call installer. | Call Professional |
| Huawei | — | String voltage too high | Call installer — may need string redesign | Call Professional |
| Huawei | — | Overtemperature | Improve ventilation, shade inverter | Monitor |
| Solis | 101 | Grid over-voltage | Self-resolves. Persistent: report to TNB | Monitor |
| Solis | 201 | Insulation resistance low — water ingress | URGENT: Shut DC isolator, call installer 24hr | Call Professional |
| Solis | 301 | Overtemperature | Shade inverter, clear 30cm all sides | Monitor |
| Solis | 401 | Fan failure — inverter cannot cool | Call installer for fan replacement | Call Professional |
| Growatt | 103 | Overtemperature — very common in Malaysia | Improve ventilation/shade. Persistent: call installer | Monitor |
| Growatt | 101 | Grid over-voltage | Self-resolves. Persistent daily: report TNB | Monitor |
| Growatt | 302 | Isolation fault — check wiring | Check wiring for water damage. Call installer. | Call Professional |
| Deye | F01 | Grid over-voltage | Self-resolves. Persistent: check with installer | Monitor |
| Deye | F08 | Isolation fault | Call installer — may indicate water ingress | Call Professional |
| Deye | F23 | Overtemperature | Improve airflow around inverter location | Monitor |
Error codes may vary by firmware version. Always cross-reference with your inverter manual or manufacturer app.
TNB Meter & Solar ATAP Issues
How Solar ATAP crediting actually works
Under Solar ATAP (GP/ST/No. 60/2025), exported electricity is credited on your bill at the TNB Energy Charge — RM0.2703/kWh, or RM0.3703/kWh above 1,500 kWh a month. Your bidirectional meter tracks: (1) kWh imported from the TNB grid and (2) kWh exported to TNB. The export credit offsets your bill, but unused credit is forfeited at the end of each billing period — it does not carry over. Self-consumed solar saves more (about RM0.4443/kWh) than exported solar earns, which is why load shifting (running appliances during solar hours) matters.
Verifying your meter is bidirectional
A proper bidirectional (smart) meter shows two readings: import kWh (energy you buy from TNB) and export kWh (energy your solar sends to grid). If your meter only shows one reading, it may be an old single-direction meter. Call TNB at 15454 to verify. The bidirectional meter installation should have been done as part of your Solar ATAP CONNECT application — if it was not done, your system may not be correctly registered.
Comparing inverter data vs TNB bill — what to expect
Your inverter monitors total solar generation. Your TNB bill shows net import. To reconcile: Bill savings = kWh self-consumed x your avoided rate (RM0.4443/kWh under the RP4 domestic tariff, or RM0.5443 above 1,500 kWh a month). Self-consumption = Total generation − kWh exported to grid. If inverter shows 400 kWh generated but your bill only dropped by 200 kWh equivalent, check your export reading — you may be exporting a lot. Solution: shift more loads to 9am-3pm solar peak hours.
Dirty Panels: Tropical Cleaning Guide
Tropical Soiling Types
Tropical Algae
Green/black film on glass. Grows in humidity. Needs brushing, not just water rinse.
Bird Droppings
Creates permanent hotspot if left. Hard calcium deposit — soak first, then wipe.
Construction Dust
Fine silica dust from nearby sites. Electrostatically attracted. Needs wet cleaning.
Fallen Leaves
Complete shading on covered area. Clean monthly if trees are nearby.
Air Pollution
PM2.5/PM10 from traffic. Accumulates faster in KL, PJ, Klang industrial areas.
Safe Cleaning Protocol (Malaysia)
- 1Time it right: clean at 6am-8am or after 5pm — avoid midday heat (thermal shock risk on hot glass)
- 2Use soft water: hard water leaves calcium deposits. Rainwater or filtered water preferred.
- 3Equipment: Long-handled soft squeegee or microfibre mop. Never abrasive pads.
- 4Algae/stubborn stains: diluted white vinegar (1:10 water) on cloth, wipe gently, rinse thoroughly
- 5Never use pressure washer — can force water into junction boxes
- 6Safety first: never step on panels. Use roof ladder and safety harness.
- 7Cost: Professional cleaning RM150-300 (residential 8-20 panels)
Wiring & MC4 Connector Issues
MC4 Connector Issues in Malaysia
Humidity corrosion
RH >80% year-round corrodes non-IP67 connectors. Look for green/white oxidation.
Improperly mated MC4
You must hear a 'click' when mating. Loose connectors arc and cause fire risk.
UV degradation
Connector housing becomes brittle after 5+ years of UV. Inspect at annual service.
Generic vs branded
Staubli MultiContact and Amphenol MC4 outperform generic connectors significantly in tropical humidity.
DIY Inspection Checklist
SAFETY WARNING
DC cables carry 300-800V even with inverter off (as long as daylight). Never disconnect MC4 connectors during daylight. Only shut off the DC isolator on the rooftop disconnector box.
- Visual inspection from ground: look for drooping cables or UV-whitened insulation
- Check conduit entry points for water ingress marks (brown staining)
- Ensure cable clips are intact — vibration loosens them in high-wind areas
- Any smell of burning plastic near inverter = call installer immediately
Lightning & Surge Protection
Malaysia: A Lightning-Prone Climate
Thunderstorms are frequent across Malaysia. Every Malaysian solar system MUST have proper lightning protection — not optional.
Required Protection
- DC-side SPD (Class I+II) — protects panel strings
- AC-side SPD (Type 2) — protects inverter AC output
- Proper system earthing/grounding to copper earth rod
- Lightning air terminal if building is unprotected
- Metal conduit for DC cable runs where possible
After a Lightning Strike — Check This
- 1Check SPD indicator window — red = triggered, replace before restart
- 2Restart inverter — note any error codes displayed
- 3Inspect visible wiring for burn marks or melted insulation
- 4Check inverter casing for scorch marks or burn smell
- 5File an insurance claim if damage is confirmed (check your home or solar policy)
Severity Guide: When to DIY vs Call a Pro
Green — DIY Safe
- Cloudy/rainy day low output — normal monsoon
- Panel cleaning (ground-accessible panels)
- Checking isolator switches are on
- Monitoring inverter app for error codes
- Trimming nearby vegetation (by professional arborist)
Yellow — Monitor & Schedule
- Progressively declining output over months
- Inverter overtemperature errors (improve ventilation first)
- Output 10-20% below same month last year
- Grid over-voltage errors (report to TNB)
- New shading from tree/building (needs assessment)
Red — Call Professional Now
- DC arc fault error (check your inverter manual for the alarm code) — fire risk
- Cracked or shattered panel glass
- Burning smell anywhere in system
- Inverter completely non-functional after troubleshooting
- Post-lightning strike — full inspection required
- Insulation fault (Solis 201, Growatt 302) — water ingress
Malaysia Solar Maintenance Checklist
- Check inverter display — no red lights or fault codes
- Log monthly kWh generation from inverter app
- Quick visual inspection of panels from ground level
- Check if any new shading (tree growth, construction)
- Clean panels — water and soft cloth, early morning
- Compare generation vs same quarter last year
- Check all visible wiring and conduit for damage
- Verify SPD indicator lights are green
- Check inverter ventilation slots are clear of debris
- Professional inspection by a SEDA-registered installer (RPVSP)
- Thermal imaging scan to identify hotspots in panels
- MC4 connector torque check and resealing if needed
- Earthing/grounding continuity test
- Review insurance policy — ensure coverage is current
- Check inverter firmware is updated to latest version
- Full string IV curve test to verify panel performance
Frequently Asked Questions
System Underperforming? Talk to Trexon
Trexon is a SEDA-registered installer (RPVSP). Send us your inverter fault code, generation data and latest TNB bill, and we will reply with the next steps.
