Your air compressor keeps tripping the circuit breaker. You reset it. It trips again immediately. This isn’t just annoying, it’s a warning signal that could cost you thousands in emergency repairs and lost production time. Here’s what’s causing it and how to fix it.
The 8 Most Common Causes
Your circuit breaker trips when the compressor draws more current than it’s rated for. This isn’t a malfunction, it’s a warning that something is wrong.
Here’s what’s causing it:
1. Failed Start Capacitor (Most Common)
The start capacitor gives your motor the electrical “jolt” needed to start. In Singapore’s hot, humid climate, capacitors degrade faster.
Signs:
- Motor hums but doesn’t turn over
- Breaker trips within 1-2 seconds
- Happens every startup attempt
Who’s affected: Marine applications (humidity) and construction sites (temperature extremes)
DIY fix? No, dangerous voltage involved
2. Failed Unloader Valve
This valve releases trapped pressure when the compressor shuts off, allowing easier restart.
Signs:
- No “hiss” sound when compressor stops
- Starts fine when tank is empty
- Trips when restarting with pressure
Singapore concern: Salt air accelerates corrosion in marine/offshore environments
DIY fix? Maybe, if you are mechanically inclined
3. Clogged Air Filters
Restricted airflow forces the motor to work harder, drawing more current. Also causes dangerous temperature spikes (93°C+).
Signs:
- Grey, dusty filter not changed in 6+ months
- Reduced air pressure
- Compressor running hotter
Singapore reality: Change filters 30-40% more often than manufacturer specs due to humidity and salt spray
DIY fix? Yes, 15 minutes, massive impact
4. Insufficient Electrical Capacity
Your circuit can’t handle the compressor’s startup current (5HP units can spike to 60-80 amps).
Signs:
- Works on some circuits, fails on others
- Worked at previous location
- Runs when nothing else shares the circuit
Quick reference:
- Small units (≤3HP): 20A breaker
- Medium units (3-5HP): 30A+ breaker
- Three-phase: Check nameplate
⚠️ Never upsize breakers without verifying wire gauge—fire hazard!
DIY fix? Only if you’re a qualified electrician
5. Motor Bearing Failure
Worn bearings create friction, forcing the motor to draw more current.
Signs:
- Disconnect power, drain tank, manually rotate pulley
- Should turn smoothly
- Red flags: stiffness, grinding, won’t turn
Singapore challenge: 30-35°C ambient temperatures accelerate wear; marine units face vibration and salt air
DIY fix? No, require specialized work
6. Low Voltage / Power Quality
Insufficient voltage forces higher current draw (Power = Voltage × Current).
Signs:
- Measure voltage during startup
- Should stay 218-242V for 230V systems
- Greater drop = wiring/power issues
Construction concern: Long extension cords and temporary power create voltage drop
DIY fix? Check connections, but usually needs professional work
7. Aged Circuit Breaker
Breakers wear out, becoming sensitive and tripping below rated capacity.
Signs:
- Works on different circuit (same rating)
- Breaker warm during operation
- Breaker 10+ years old
DIY fix? Only if qualified for panel work
8. Compressor Oil Issues
Wrong viscosity, contamination, or incorrect levels affect efficiency.
Problems:
- Overfilled = hydraulic lock
- High viscosity = startup resistance
- Contaminated = increased friction
Check:
- Oil level within manufacturer range
- Correct viscosity for tropics (ISO VG 46 or 68)
DIY fix? Yes, straightforward
⚠️ Do NOT Keep Resetting a Tripping Breaker
Each reset risks:
- Motor winding damage
- Breaker degradation
- Fire hazards
- Catastrophic failure
Your breaker is protecting you. Don’t defeat it—fix the root cause.
When to Call a Professional
You can handle:
- Cleaning/replacing air filters
- Checking for air leaks
- Verifying circuit isn’t overloaded
- Testing no-load startup (empty tank)
- Checking oil level
Call immediately if:
- Breaker trips within seconds
- Grinding or squealing noises
- Burning odors
- Motor excessively hot
- Won’t build pressure
- Basic troubleshooting failed
Professional work needed:
- Capacitor replacement (dangerous voltage)
- Unloader valve repair (disassembly required)
- Bearing replacement (specialized tools)
- Electrical fault diagnosis
- Pressure switch calibration
Frequently Asked Questions
How much does diagnosis usually cost?
Costs vary by compressor size and complexity. We provide transparent quotes before work begins—no hidden fees.
Same-day repair possible?
Yes for common issues (capacitors, filters, unloader valves). Complex repairs (bearings) may need 1-2 days.
Can I just install a bigger breaker?
No, unless a qualified electrician verifies your wiring can handle it. Oversized breakers on undersized wire = fire hazard.
What Happens When You Wait vs. Act
Wait:
Day 1:
Occasional trips
Week 1:
Frequent trips, productivity drops
Week 2:
Complete failure during peak operation
Week 3:
Emergency repairs, production idle
Act Now:
Today:
Diagnosis identifies issue
Tomorrow:
Scheduled repair
Next week:
Normal operation
Next month:
No surprises
Get Your Compressor Fixed Today
Why choose us:
- ✓ Quick emergency response
- ✓ Years of tropical climate expertise
- ✓ Honest diagnostics
- ✓ All major brands (DENAIR, Atlas Copco, Ingersoll Rand)
📱 Click here to WhatsApp Us: +65 8847 6838
Contact VU Technology
Singapore’s Trusted Partner for Compressed Air Solutions Since 2020
| +65 8847 6838 or +65 8904 2268 | |
| WhatsApp Us | |
| sales@vutechnology.com.sg | |
| 1 Sunview Rd, #04-18, Singapore 627615 |
Schedule your consultation and receive your detailed quotation within 48 hours.