Collection of various types of faults and troubleshooting methods for central air conditioning!

Failure phenomenon

cause

elimination method

Fan does not turn

1. Power failure

2. Forgot to plug in the power

3. Low voltage

4. Wiring error or loose terminal

5. Motor failure

6. Poor capacitor

7. Poor switch contact

1. Find out the cause or wait for power recovery

2. Insert the plug

3. Find out the cause

4. Check the circuit with a multimeter and repair it

5. Use a multimeter to check, repair or replace

6. Replace

7. Repair or replace

The fan rotates but no air or low air volume

1. Abnormal power supply voltage

2. Reverse

3. There are obstacles in the tuyere

4. The air filter is blocked

1. Find out the cause

2. Change the wiring

3. Remove

4. Cleaning

The wind is not cold

(or not hot)

1. There is air in the coil

2. The water supply cycle stops

3. The regulating valve is closed

4. The valve is blocked by foreign

matter

1. Exhaust air from the exhaust valve

2. Check the water pump

3. Open the regulating valve

4. Take out the foreign body

Condensation on the

outside of the case

1. Damaged internal insulation

2. The casing is burned out

when it is in contact with the flame and the insulation

3. Leakage of cold air

4. There are indoor conditions that cause condensation

1. Repair

2. Do not touch the flame, re-wrap the insulation layer

3. Repair

4. Conditions for removing condensation

Foreign body blowing out

1. There is rust on the surface of the fan blade due to corrosion

2. The air filter is damaged and deteriorated

3. Damaged and degraded insulation materials

4. Too much dust in the unit

1. Replace the fan

2. Replace the air filter

3. Replace insulation materials

4. Clean the interior

Leakage

The wires are damaged or leaking

Repair line

Leaking

1. Poor installation

2. The drip tray is tilted

3. The drain is blocked

4. There is a leak in the water pipe

5. Condensate drips from the pipe

6. Poor installation at the joint

7. Forgot to close the exhaust valve

1. Horizontal installation of the unit2. Adjust

3. Remove the blockage

4. Check and replace the water pipe

5. Check and re-insulate

6. Tighten after inspection

7. Close the valve

Fan does not stop after

shutting down

1. Switch failure

2. The control circuit is short-circuited

1. Repair or replace the switch

2. Check the circuit and eliminate the

short circuit

Vibration and noise

1. Poor installation of the unit

2. Poor housing installation

3. No loosening of the fixed fan

4. There are foreign objects in the path of the wind

5. Fan motor failure

6. Damaged fan blades

7. Loose shutters at the air outlet

8. There is air in the coil

9. Frozen water (hot water) flows too fast

10. There is a lot of air in the water

11. When using a quantitative valve, the differential pressure is too large

1. Reinstall and adjust

2. Reinstall

3. Fastening

4. Remove foreign matter

5. Repair or replace the motor6. Replace

7. Fastening

8. Exhaust air

9. Check the flow rate of water

10. Remove air from water

11. Replace the appropriate valve

Poor effect of cold air

(hot air)

1. The opening of the regulating valve is not enough

2. The coil is blocked and poor ventilation

3. There is air in the coil

4. Power supply voltage drops

5. The air filter is blocked

6. Insufficient water supply (cold and hot water)

7. Abnormal water supply temperature

8. Fan reverse

9. Obstacles to the supply air outlet and the return air outlet

10. The front panel is not installed properly

11. Air short circuit

12. Uneven indoor wind distribution

13. Improper selection of equipment

14. Air leakage from the ceiling type unit connection 15. Improper temperature adjustment

16. Room sunshine or window opening

1. Re-adjust the opening

2. Clean the coil

3. Exhaust air

4. Find out the cause

5. Clean the air filter

6. Adjust the water supply valve

7. Check the temperature of chilled water (or hot water)

8. Rewiring

9. Remove obstacles

10. Regular installation

11. Check that there are no obstacles at the air outlet

12. Check and adjust the tuyere

13. Redesign and selection

14. Repair

15. Re-adjust the air supply level

16. Close windows and hang curtains

Failure phenomenon

cause

elimination method

The air supply parameters do not match the design values

1. The capacity of the air treatment equipment is too large or too small.

2. The thermal performance of the air handling equipment product cannot reach the rated value.

3. Improper installation of air handling equipment causes partial air short circuit.

4. Air leaks in the negative pressure section of the air conditioning box or duct, and untreated air leaks in.

5. The cooling and heating medium parameters and flow rate do not match the design value.

6. The water retaining effect of the water retaining plate is not good, and the condensed water evaporates again.

7. The temperature rise of the fan and air supply pipeline exceeds the design value (the pipeline is not well insulated).

1. Adjust the parameters and flow of the cold and heat medium to make the air handling equipment reach the rated capacity; if it still does not meet the requirements, consider replacing or adding equipment

2. Check equipment, air ducts, eliminate short circuits and air leakage

3. Strengthen the insulation of wind and water pipes

4. Check and improve the water baffle of the surface cooler of the spray room to eliminate air leakage

Room temperature and relative humidity are both high

1. Insufficient cold output of the refrigerator.

2. Water spray is blocked.

3. Excessive air flow through the air handling equipment and poor heat and moisture exchange.

4. The return air volume is greater than the supply air volume.

5. Insufficient air supply (maybe the air filter is blocked).

6. The surface cooler is frosted, causing blockage.

1. Replace the refrigerator or overhaul the refrigerator equipment.

2. Clean the water spray system and nozzles.

3. Adjust the air flow through the processing equipment to make the wind speed normal.

4. Readjust the air volume of the return fan to make the room positive pressure.

5. Clean the air filter to make the air supply normal.

6. Adjust the evaporation temperature to prevent frosting.

Room temperature is suitable or low, relative humidity is high

1. The supply air temperature is low (maybe the secondary heating of the primary return air is not turned on or insufficient).

2. The water spray chamber has a large amount of water and a large amount of moisture in the supply air (may be uneven or air leakage).

3. The dew point temperature and moisture content of the machine may be high.

4. The room produces a large amount of humidity (such as increasing the humidity production equipment to flush the floor with water, air leakage, water leakage, etc.).

1. Use secondary heating correctly.2. Repair or replace the water baffle and plug the air leakage.

3. Adjust the three-way valve to reduce the mixed water temperature.

4. Reduce moisture source.

Room temperature is normal, relative humidity is low

The outdoor air has a relatively low moisture content, and has not been humidified, but is only heated and sent into the room.

1. When spraying the water room, it should continuously spray circulating water for humidification.

2. The surface cooler system should turn on the humidifier.

The measured air volume of the system is greater than the designed air volume

1. The actual resistance of the system is less than the design resistance, so the air volume of the fan increases

2. The fan capacity is too large when designing

1. The number of revolutions of the fan can be changed if possible2. Close the small air volume control valve to reduce the air volume

The measured air volume of the system is less than the designed air volume

1. The actual resistance of the system is greater than the design resistance and the air volume of the fan is reduced

2. There is blockage in the system

3. System leakage

4. Insufficient output of the fan (the fan cannot reach the design capacity or the impeller rotates in the wrong direction, the belt slips, etc.)

1. When conditions permit, improve air duct components to reduce system resistance

2. Check and clean up possible obstructions in the system

3. Blockage

4. Check and eliminate factors that affect the output of the fan

The total air volume of the system does not match the total air volume, the difference is large

1. The air volume measurement method and calculation are incorrect

2. System leakage or short

1. Review measurement and calculation data

2. Check plugging and eliminate short circuit

The dew point temperature of the machine has reached the requirement or is low, but the room temperature is slow

1. The air supply volume is less than the design value, and the number of air changes is small

2. There is a system with secondary return air, and the secondary return air volume is too large

3. There are many rooms in the air-conditioning system and uneven air distribution

1. Check whether the fan model meets the design requirements, whether the impeller steering is correct, whether the belt is loose, open the large air supply valve, and eliminate the factors of insufficient air flow

2. Adjust to reduce the secondary air return

3. Adjust to make the air volume of each room evenly distributed

Room air velocity exceeds the allowable velocity

1. The air outlet speed is too large

2. The total air supply is too large

3. The form of the air outlet is inappropriate

1. Increase the area of the air outlet or increase the number of air outlets, and open the large air outlet regulating valve

2. Reduce the total air volume

3. Change the form of the air outlet and increase the turbulence coefficient

The air velocity in the room is unevenly distributed, and there are dead spots

1. Poor consideration of airflow organization design

2. The air volume of the air supply outlet is not adjusted uniformly and does not meet the design value

1. Adjust the position of the air supply outlet or increase the number of air supply outlets according to the measured airflow distribution diagram

2. Adjust the air volume of the air outlet to meet the design requirements

The air in the room is not fresh

1. Insufficient fresh air volume (the fresh air valve is not fully opened, the section of the fresh air duct is small, the air filter is blocked, etc.)

2. The number of personnel exceeds the design number

3. There are oxygen consumption factors such as smoking or burning indoors

1. Take symptomatic measures to increase the amount of fresh air

2. Reduce unnecessary personnel

3. It is forbidden to smoke and engage in non-compliant itchy activities in air-conditioned rooms

The noise in the room is greater than the design requirements

1. Fan noise is higher than the rated value

2. The wind speed of the wind pipe, valve and tuyere is too high, which will cause wind noise

3. The noise reduction equipment of the air duct system is not perfect

1. Determine the noise of the fan, check whether the fan impeller hits the shell, whether the bearing is damaged, whether the vibration reduction is good, and deal with the symptoms.

2. Adjust various valves and air outlets to reduce excessive wind speed

3. Add silencing elbow and other equipment

The cleanliness of the room does not meet the design requirements

1. The efficiency of the air filter does not meet the requirements

2. The dust in the equipment and air duct was not cleaned up as required during construction and installation

3. Operation management is not cleaned and cleaned as required

4. The production process does not meet the design requirements

5. The positive pressure in the room does not meet the requirements, and the outdoor dust infiltrates

1. Replace the unqualified filter equipment

2. Try to clean the dust in the equipment tube

To

3. Strengthen operation management

4. Improve process

5. Increase the number of air changes and positive pressure

Failure phenomenon

cause

elimination method

The pump does not absorb water, the pointer of the water pressure gauge and the suction vacuum gauge swings violently

The water entering the pump is not enough, the suction pipe or seal is leaking

Tighten the screw plugs, seals and other leaks after repairing, vacuum or water injection

The pump does not absorb water, and there is a high vacuum before it absorbs water

The bottom valve is not opened, or is blocked, the water absorption resistance is too large, and the water absorption level is too low

Correct or change the bottom valve, clean or change the suction pipe, lower the pump position

The outlet pipe of the water pump is under pressure, but the pipe still does not emit water

The resistance of the outlet pipe is too large, the direction of rotation is wrong, and the impeller is blocked

Check or shorten the water pipe and check the steering of the motor, remove the water pipe joint, and clean the impeller

Flow rate is lower than expected

The pump is blocked, the mouth ring is worn too much, and the pipe is too small

Clean the water pump and replace the big pipe, replace the mouth ring

The pump consumes too much power

The stuffing box is compressed too tightly, the stuffing box is heated or the mechanical seal is stuck, the impeller is loose, the impeller or the bearing is damaged, and the water supply volume of the water pump increases

Check and replace the stuffing box or check the mechanical seal impeller, open a small outlet pipe valve to reduce the flow

Bearing overheating

Without oil, the water pump shaft and the motor shaft are not on the same centerline

Fill oil, align shaft center or change bearing

The internal sound of the water pump is abnormal, and the water pump does not supply water

The flow rate is too large, the resistance in the suction pipe is too large, the water absorption height is too large, there is air infiltration at the suction place, the temperature of the liquid being conveyed is too high, or the impeller sucks solid foreign objects

Open a small outlet valve to reduce the flow, check the pump suction pipe, check the bottom valve, reduce the suction height, solve the leak, and reduce the temperature of the liquid

Pump vibration

The pump shaft and the motor are not on the same centerline or the pump shaft is inclined. Check whether the bearing is damaged

Align the shaft center lines of the water pump and the motor, and check the bearings

Failure phenomenon

cause

elimination method

Does not start

1. Power failure

2. Forgot to plug in the power

3. Low power supply voltage

4. Wiring error, disconnection, loose connection terminal

5. Bad wiring terminals

6. Thermal relay action

7. Loose connection device

8. Loose terminals and open phase operation

9. Failure of blower motor

10. The transmission belt is disconnected

1. Check the reason and wait for the call

2. Insert the plug

3. Find out the cause

4. Check and repair the circuit

To

5. Fastening

6. Press the reset button

7. Inspection and repair

8. Fasten the terminals

9. Repair or replace the motor

10. Replace the transmission belt

Cooling capacity is not strong

1. The selection is not matched and the capacity is too small

2. The fan does not run and there is no wind

3. Bearing wear

4. Shaft breakage

5. The angle of the blower blades is wrong, and the motor load is too large

6. Damaged fan blades

7, the transmission belt is loose

8. Too much circulating water

9. Insufficient circulating water

10. Short circuit of exhaust air

11. Inhale the hot air

12. Insufficient air intake

13. Circulating water drift14. Filling material plug

15. The hole of the dispersing tank is blocked

16, the water diffuser is blocked

1. Redesign and select

2. Check the power supply and wiring

3. Replace

4. Replace

5. Adjust the blade angle

To

6. Replace

7. Replace

8. Adjust the water supply valve and turn it off

9. Adjust the water supply valve and open it

10. Remove faulty obstacles

11. There should be no heat source around the cooling tower

12. Check the air road

13. Sweep the dispersion tank and adjust the opening of the inlet valve

14. Cleaning

15, cleaning

16. Replace

Reduced circulating water during operation

1. The spray pipe of the spray tank is blocked

2. The water supply pipe is blocked

3. The valve of the water supply pipe is not fully opened

4. Insufficient water supply pressure

5. The water pump is not matched and is too small

6. Unreasonable piping design and small pipe diameter

1. Cleaning

2. Clear

3. Fully open the water supply valve4. Find out the cause and adjust the pressure

5. Replace the water pump

6. Reconfiguration

More water brought out during operation

1. Too much circulating water

2. Bias flow of circulating water

3. Excessive air volume

4. The fan does not match and is too large

1. Adjust the valve

2. Sweep the dispersion tank and adjust the opening of the inlet valve

3. Check the fan and impeller

4. Replace

Water overflows in the water tank during operation

1. The water tank is blocked

2. There is a lot of circulating water, and scattered water drips from above

3. The structure of the water tank is unreasonable

1. Clean up

2. Adjust

3. Repair

Vibration and noise during operation

1. The shaft of the blower is bent

2. The shaft damage of the blower

3. Damage to the bearing

4. Foreign matter in the bearing

5. Bearing lack of oil

6. The blade screws are loose

7. The fan blade collides with other parts

8. The connection part of the cooling tower shell is loose

9. The voltage is too low and the motor makes an abnormal sound

1. Replace

2. Replace

3. Replace

4. Disassembly and cleaning

5. Come on

6. Fastening

7. Repair8. Inspection and repair

9 find out the cause

During operation, the fan motor overheated