Complete Maintenance Checklist for Industrial Fans
This guide covers the full maintenance checklist for fans, organized by weekly, monthly, quarterly, and annual inspection items. Print it out and post it in the equipment room — frontline staff can follow it step by step.
General Maintenance Principles
✅ See it, touch it, hear it
See: Instrument readings, appearance, oil level
Touch: Temperature, vibration, leakage
Hear: Operating sounds, abnormal noise
⚠️ Safety First:
All inspections of rotating parts must be done with the machine shut down!
All electrical work must be done with power disconnected and lockout/tagout applied!
📅 Weekly Inspection Items (Per-Shift Patrol)
No.
Inspection Item
Method
Standard
Action
1
Fan operating sound
Listening rod or ear
Steady "humming" sound, no irregular noise
Stop immediately if abnormal noise detected
2
Bearing temperature
Hand touch or infrared thermometer
≤ 70°C
Alarm and shutdown if > 80°C
3
Motor temperature
Infrared thermometer
≤ 95°C
Investigate cause if overheated
4
Vibration
Hand touch or vibration meter
No noticeable vibration
Investigate root cause if vibration is excessive
5
Lubricating oil level
Sight glass observation
1/3 to 1/2 of oil level
Top up if low; drain if overfilled
6
Current reading
Ammeter
≤ Rated current
Investigate load if current is exceeded
7
Inlet/outlet pressure
Pressure gauge
Within design range
Check system resistance if pressure is abnormal
8
Anchor bolts
Visual + wrench
No looseness
Tighten if loose
9
Flexible connection condition
Visual inspection
No damage, no air leakage
Replace if damaged
10
Equipment room ventilation
Hand feel + visual
Good ventilation
Improve ventilation if needed
Inspection Log: Fill in the "Fan Operation Log". Note the cause and corrective action for any abnormalities.
📅 Monthly Inspection Items
No.
Inspection Item
Method
Standard
Action
1
Bearing grease replenishment
Grease gun
Apply per specified amount
Do not overfill (1/3 to 1/2 of cavity)
2
Coupling condition
Visual + hand feel
No looseness, no wear
Tighten bolts if loose; replace if worn
3
Belt tension
Hand press — 10–15 mm deflection
Proper tension
Tighten if too loose; replace if aged
4
Filter differential pressure
Differential pressure gauge
≤ Rated differential pressure
Clean or replace filter if exceeded
5
Electrical wiring terminals
Visual + wrench (after power-off)
No looseness, no overheating
Tighten if loose; replace if overheated
6
Safety protection devices
Simulated test
Normal actuation
Repair or replace if malfunctioning
7
Valve actuation test
Open/close test
Smooth operation
Lubricate or repair if stiff
Key Reminder: For belt-driven fans, belt tension and wear must be checked every month. A slipping belt increases energy consumption by 5%–10%.
📅 Quarterly Inspection Items
No.
Inspection Item
Method
Standard
Action
1
Impeller dust accumulation
Open inspection door, visual check
No significant dust buildup
Clean if heavily accumulated
2
Impeller wear condition
Hand touch + caliper measurement
No significant wear or notches
Replace or weld-repair if severely worn
3
Casing inner wall
Visual inspection
No rust, no damage
Paint rusty areas; weld-repair damaged areas
4
Foundation settlement
Level instrument
No significant settlement
Reinforce foundation if settlement is excessive
5
Pipeline supports
Visual + wrench
No looseness, no deformation
Tighten if loose; straighten if deformed
6
Vibration isolator condition
Visual + hand feel
No damage, no aging
Replace if failed
7
Full lubricating oil replacement
Drain, flush, and refill with new oil
Use same grade oil
—
8
Motor insulation test
Megger (insulation resistance tester)
≥ 0.5 MΩ
Bake-dry or repair if insulation is low
Key Reminder: The inspection door must be opened every quarter to check the impeller! Dust buildup is invisible from the outside — by the time you notice a problem, it's already too late!
📅 Annual Overhaul Items
No.
Inspection Item
Method
Standard
Action
1
Impeller dynamic balancing
Dynamic balancing machine
Residual imbalance ≤ G2.5
Correct if out of tolerance
2
Bearing inspection/replacement
Disassembly inspection
Clearance ≤ standard value
Replace if out of tolerance
3
Shaft wear inspection
Dial indicator
Shaft wear ≤ 0.1 mm
Major repair or replace if worn
4
Shaft alignment re-check
Dial indicator
Radial ≤ 0.05 mm, face ≤ 0.03 mm
Re-align if out of tolerance
5
Anti-corrosion treatment
Sandblasting + painting
No large-area rust
Redo anti-corrosion coating
6
Full electrical inspection
Professional testing
—
—
7
Performance test
Airflow & pressure test
Efficiency drop ≤ 5% vs. new machine
Investigate cause if efficiency is low
⚠️ Shut Down Immediately If Any of the Following Occurs
Bearing temperature suddenly rises above 95°C
Clear metallic rubbing or impact sounds are heard
Vibration suddenly increases to more than 2× the normal value
Motor emits smoke or a burning smell
Current fluctuates sharply or exceeds the rated value by more than 10%
Flexible connection is severely damaged with major air leakage
Any other condition that endangers personal safety
📋 Maintenance Record Template
It is recommended to establish a maintenance file for each fan:
Date and model of replaced bearings, impellers, motors
Lubrication records
Date and type of oil added or changed
Running hours
Cumulative operating time
💡 Common Maintenance Mistakes
❌ Mistake 1: "If it's not broken, don't touch it — fix it only when it breaks"
Preventive maintenance costs only 1/10 of corrective maintenance. Waiting until failure leads to far greater losses.
❌ Mistake 2: "More grease is always better"
Overfilling causes overheating. 1/3 to 1/2 of the cavity is the optimal level.
❌ Mistake 3: "A little extra vibration is fine — as long as it's still running"
Excessive vibration is a precursor to failure. By the time it stops, the damage is done.
❌ Mistake 4: "If it runs smoothly, no need to check the impeller"
Impeller dust buildup is invisible from the outside. By the time you notice, efficiency has already dropped 10%–20%.
Summary
A fan is like a car — 70% maintenance, 30% repair. Spending ¥1 on daily maintenance saves ¥10 in repair costs and hundreds of thousands in downtime losses. Follow this checklist, and your failure rate will drop dramatically.
