Temperature Fault
The internal temperature monitoring circuit has detected excessive heat buildup within the power supply enclosure, typically exceeding 70°C ambient or 85°C at critical components. This triggers protective shutdown to prevent component damage and indicates insufficient cooling or increased power dissipation from failing components.
Error Code
AL70
Severity
Fault
Equipment
Power Supply
Manufacturer
Danfoss
Red temperature fault LED flashing in 2-second intervals on control board
Power supply output shuts down after 30-60 seconds of operation under load
Cooling fan runs continuously at maximum RPM but inadequate airflow measured
Heat sink temperature exceeds 80°C when measured with infrared thermometer
Electrolytic capacitor tops showing signs of thermal stress or bulging
Burnt smell emanating from power supply enclosure during operation
Blocked air intake filters reducing cooling airflow by more than 40%
Failed cooling fan bearing causing reduced RPM below 2000 RPM specification
Thermal interface material degradation between semiconductors and heat sinks
High ESR output filter capacitors generating excessive I²R heating
Power MOSFET or diode junction temperature rise due to increased forward voltage drop
Ambient temperature exceeding maximum specified operating range of 40°C
Execute lockout/tagout procedure and allow 30-minute cooldown period before inspection
Clean all air intake filters and verify unrestricted airflow through enclosure
Test cooling fan current draw and RPM, replace if below 80% of rated specification
Remove and clean all heat sinks, apply fresh thermal compound to all semiconductor mounting surfaces
Measure ESR of all electrolytic capacitors, replace any exceeding 100 milliohms
Check forward voltage drop of all power diodes and MOSFETs under rated current
Install power supply with proper clearances and verify ambient temperature <35°C during full-load operation
Safety First: Always isolate power and follow LOTO (Lockout/Tagout) procedures before working on electrical components. If unsure, contact a certified repair technician.
Get fault code alerts for Danfoss equipment
Weekly repair tips, new fault codes, maintenance guides — free.
Get Your Equipment
Back in Action — Fast
Send us your faulty industrial electronics. Our engineers will diagnose it and provide a detailed quote within 24 hours — with no obligation to proceed.
Free Evaluation
No obligation
48hr Turnaround
Fastest in India
6-Month Warranty
Every repair
No Fix, No Charge
Zero risk policy
Pan-India Pickup
Doorstep service