How long is the maintenance cycle of fire smoke exhaust fan?

The maintenance cycle of fire smoke exhaust fan should be comprehensively determined according to the equipment operation frequency, use environment and specification requirements. The core goal is to ensure that the fan has stable performance in daily standby, and can be started immediately and run up to standard in case of fire emergency. According to Technical Standard for Smoke Prevention and Exhaust System of Buildings (GB 51251-2017) and industry operation and maintenance practice, the maintenance cycle can be divided into three levels: daily inspection, regular maintenance and annual inspection. The specific requirements are as follows:

I. Daily inspection: once a day/week, focusing on "status confirmation"

The daily inspection focuses on "quick troubleshooting of obvious problems", and it is not necessary to disassemble the equipment, and it is carried out by on-site operation and maintenance personnel (such as property electricians and factory safety officers), focusing on confirming whether the fan is in a "ready-to-use" state:

Daily inspection (for high-frequency scenes)

Applicable scenarios: shopping malls, hospitals, underground garages and other places with dense people or high demand for smoke exhaust.

Check content:

Appearance of the fan: the casing and impeller are not obviously deformed or damaged, and there is no debris accumulation (such as dust, leaves and birds nesting);

Power supply and control: the indicator light of the distribution box is normal (no fault alarm), and the power switch is in the "automatic/standby" position to avoid being switched to "manual shutdown" by mistake;

Linkage signal: Confirm that the linkage line with the fire damper and fire control room is not loose (the "standby state detection" can be triggered remotely through the control room without starting the fan).

Weekly inspection (for ordinary scenes)

Applicable scenarios: factories, warehouses and other places where people are not on duty 24 hours a day.

Inspection content: On the basis of daily inspection, add "manual turning"-after turning off the power supply, turn the fan impeller by hand to make sure that the rotation is smooth and there is no jamming or abnormal sound (if there is jamming, it may be that the bearing is short of oil or the impeller is dirty).

2. Regular maintenance: once every 3 months/6 months, focusing on "performance maintenance"

Regular maintenance needs to disassemble, clean and lubricate the core components of the fan, which shall be carried out by professionally qualified operation and maintenance personnel (such as personnel of the fire maintenance company) to avoid the failure of fan start-up or performance degradation due to aging of components:

The maintenance cycle applies to the core maintenance content of the scenario.

Wet/dusty/corrosive environment every 3 months (such as pickling workshop of food processing factory, underground garage, chemical auxiliary building) 1. Cleaning: disassemble the air inlet protective net, and use compressed air to purge the dust and oil stains in the impeller and casing (food factory should avoid the odor caused by residual oil stains);

2. Lubrication: Fill the motor bearing with special grease (such as lithium-based grease), and the amount of oil should be 1/2-2/3 of the inner space of the bearing to avoid overheating of the bearing;

3. Seal inspection: check the connecting seal (such as rubber gasket) between the fan and the pipeline. If it is aging or cracked, it should be replaced in time to prevent air leakage during smoke exhaust.

Dry/clean the environment every 6 months (such as the non-oil fume area of office buildings and shopping malls). 1. Repeat the cleaning and lubrication steps "every 3 months" (which can appropriately simplify the purging efforts);

2. Motor inspection: use a multimeter to detect the insulation resistance of the motor winding (it needs to be ≥0.5MΩ, below which there may be leakage risk);

3. Impeller balance: Check whether the impeller is out of balance due to fouling (if it vibrates obviously during operation, it needs to be disassembled and cleaned or corrected for dynamic balance).

Iii. annual inspection: once a year, focusing on "compliance and emergency performance verification"

The annual inspection needs to simulate the fire scene and fully verify the "emergency starting ability" of the fan. The results need to be recorded (as the basis for fire inspection and annual inspection) and must be carried out by institutions with fire technical service qualifications:

Functional linkage test

Trigger the "smoke exhaust fan start signal" in the fire control room, and check whether the fan starts normally within 30 seconds (the response time required by the specification is ≤60 seconds);

Simulate "high temperature scene of flue gas": use heating equipment to make the temperature in the flue gas pipeline reach 280℃, and check whether the fire damper closes automatically and whether the fan stops synchronously (the linkage logic should meet the requirements of GB 51251).

Performance parameter detection

Use professional equipment (such as anemometer and anemometer) to measure the actual smoke discharge and total pressure of the fan. Compared with the design parameters, the deviation should be ≤10% (if the deviation is too large, the problems such as pipe blockage and impeller wear should be investigated);

Detection of fan operation noise: the sound pressure level shall be measured at a distance of 1m from the fan, which shall meet the design requirements (usually ≤85dB). If the noise exceeds the standard, the bearing wear shall be checked or a silencer shall be installed.

Component aging assessment

Check the aging of motor carbon brush (if it is a brushed motor), capacitor and control circuit. The core components (such as motor and bearing) that have been used for more than 5 years need to be evaluated and replaced if necessary;

Check the corrosion degree of fan casing and impeller (especially in wet/corrosive environment). If there is corrosion perforation, it is necessary to repair welding or replace parts to prevent structural failure.

Fourth, special circumstances: scenes that require "immediate maintenance"

In case of the following situations, you don't need to wait for a fixed period, you need to stop the machine immediately to check the maintenance:

Abnormal vibration and abnormal sound (possibly due to foreign body stuck in the impeller and bearing damage) occur when the fan is running;

The alarm in the fire control room shows "fan failure" (such as motor overload and power failure);

After experiencing extreme weather (such as rainstorm and typhoon), the fans installed on the roof or in the open air should be checked for water ingress and loose parts;

After a fire breaks out in a building (whether the fan is started or not), it is necessary to completely disassemble and check whether the impeller and motor are damaged by high temperature and whether the linkage system is normal.

summary

The maintenance cycle of fire smoke exhaust fan follows the principle of "high frequency inspection to prevent misjudgment, regular maintenance to prevent aging, and annual inspection to prevent failure". The core is to ensure that the equipment is always in the state of "ready for use and up to standard when started" through multi-level management of "daily+regular+emergency". Special attention should be paid: all maintenance records (such as inspection date, personnel, problems and treatment results) should be kept for at least 3 years as the basis for fire department inspection and building safety assessment.