Troubleshooting

Problem	Possible cause	Solution
Short of capacity	Liquid flow too low	Check the valves/filters.
Leakage in system/coil block	Check the connections, brazings in the heat transfer section and the tubing. When there is a leakage in the heat transfer section, contact the manufacturer for further repair instructions.
Wrong flow direction in the circuiting	See Liquid cooler tube connections.
Air in system	Ventilate the system.
Fan/fans not operating	Locate the problem and repair it or change the fan unit.
Heat transfer section blocked up/ dirty	Vacuum clean/wash the heat transfer section.
Incoming air flow too low	Check the minimum distance between the unit and the obstacles (see Positioning). Ensure that there are no obstacles for the air flow.
Wrong fan rotation direction	Wrong phase sequence. Change the connection on motor coupling or from the switch board.
Inlet air too warm	Check the location of the units (see Positioning). Shade the unit from the sun. The heat transfer capacity can be increased by a water jet system. There may be hot air recirculation in the unit. Use streamers and/or wind barriers to minimize recirculation.
Vibration in the unit	Broken fan	Repair or change the fan.
Dirty fan	Clean the device; if it is unstable after cleaning, replace the fan.
Damaged vibration dampers	Install new vibration dampers.
Fan does not start	Fan frozen in fan collar	Remove ice.
Fuse blown out	Replace the fuse.
Overload release	Check and reset the device from the overload release switch.
Wrong supply voltage	Check that the supply voltage corresponds to the value marked on the motor sign. Restore power supply. Note: EC-fans: The error message resets automatically. The device restarts automatically without an advance warning.
Wrong connection	Check the connections: see Fans and fan connections and the product nameplate.
Break in coil or control circuit	If the switch is in the OFF position, there is a bumbling noise. Check the slack line switches. Check that the line switches close.
Mechanical failure	Check that the fan motor and fan blade rotate freely. Check the bearing and lubrication.
Short circuit in coil	Can be indicated by a blown-out fuse. Replace the motor.
One phase in motor may be broken	Check the connection.
Fan stops	Voltage break	Blown-out fuses
Low voltage	Follow the voltage given in the product nameplate. Check the connections.
Fan starts, then stops	Failure in supply voltage	Check the loose connections, fuses and control circuit.
Fan does not reach maximum speed	Wrong fan motor type	Ask the supplier about a correct type of fan.
Too low voltage at fan motor terminals because of voltage drop	Use higher voltage or a starter transformer. Check the connections and the correct cable size.
Broken rotor	Check for breaks in the short-circuiting ring. Change the rotor or motor.
Motor takes high amp	Too low voltage	Check the size of cables.
Too low supply voltage	Check the supply voltage.
Wrong rotation direction	Wrong sequence of phases	Change the connection on the motor coupling or from the switchboard.
Fan motor overheating	Motor body or cooling openings may be dirty or blocked up, hindering proper motor ventilation.	Clean the motor and and ensure free air circulation.
One motor phase may be open.	Check the connection.
Earth fault	Identify and repair.
Asymmetric supply voltage to motor terminal	Check the cables and connections.
Vibrating fan	Loose motor fixing	Tighten the fixing screws and check the alignment.
Unbalanced fan blade/Fan blades misaligned	IEC-fan: Balance the blade or change it. EC-fan: Change the fan unit.
Faulty bearings	IEC-fan: Change the motor. EC-fan: Change the fan unit.
3-phase motor running as single phase	Check the connections.
Too big axial play	Check the bearings.
Abrasive noise in fan	Fan blade is chafing against fan collar.	Check the motor centering and fixing.
Motor ventilator is chafing against the cover.	Repair the fan or cover.
Ventilator hits on insulation.	Prevent the touch.
Motor has loosened from its fixing.	Tighten the fixing bolts and rebalance the fan.
Exceptionally heavy noise of running	Air gap not centralized	Check the impeller placement and bearings.

Short of capacity

Liquid flow too low

Check the valves/filters.

Leakage in system/coil block

Check the connections, brazings in the heat transfer section and the tubing. When there is a leakage in the heat transfer section, contact the manufacturer for further repair instructions.

Wrong flow direction in the circuiting

See Liquid cooler tube connections.

Air in system

Ventilate the system.

Fan/fans not operating

Locate the problem and repair it or change the fan unit.

Heat transfer section blocked up/ dirty

Vacuum clean/wash the heat transfer section.

Incoming air flow too low

Check the minimum distance between the unit and the obstacles (see Positioning).

Ensure that there are no obstacles for the air flow.

Wrong fan rotation direction

Wrong phase sequence. Change the connection on motor coupling or from the switch board.

Inlet air too warm

Check the location of the units (see Positioning). Shade the unit from the sun. The heat transfer capacity can be increased by a water jet system.

There may be hot air recirculation in the unit. Use streamers and/or wind barriers to minimize recirculation.

Vibration in the unit

Broken fan

Repair or change the fan.

Dirty fan

Clean the device; if it is unstable after cleaning, replace the fan.

Damaged vibration dampers

Install new vibration dampers.

Fan does not start

Fan frozen in fan collar

Remove ice.

Fuse blown out

Replace the fuse.

Overload release

Check and reset the device from the overload release switch.

Wrong supply voltage

Check that the supply voltage corresponds to the value marked on the motor sign.

Restore power supply.

Note: EC-fans: The error message resets automatically. The device restarts automatically without an advance warning.

Wrong connection

Check the connections: see Fans and fan connections and the product nameplate.

Break in coil or control circuit

If the switch is in the OFF position, there is a bumbling noise. Check the slack line switches. Check that the line switches close.

Mechanical failure

Check that the fan motor and fan blade rotate freely. Check the bearing and lubrication.

Short circuit in coil

Can be indicated by a blown-out fuse. Replace the motor.

One phase in motor may be broken

Check the connection.

Fan stops

Voltage break

Blown-out fuses

Low voltage

Follow the voltage given in the product nameplate. Check the connections.

Fan starts, then stops

Failure in supply voltage

Check the loose connections, fuses and control circuit.

Fan does not reach maximum speed

Wrong fan motor type

Ask the supplier about a correct type of fan.

Too low voltage at fan motor terminals because of voltage drop

Use higher voltage or a starter transformer. Check the connections and the correct cable size.

Broken rotor

Check for breaks in the short-circuiting ring. Change the rotor or motor.

Motor takes high amp

Too low voltage

Check the size of cables.

Too low supply voltage

Check the supply voltage.

Wrong rotation direction

Wrong sequence of phases

Change the connection on the motor coupling or from the switchboard.

Fan motor overheating

Motor body or cooling openings may be dirty or blocked up, hindering proper motor ventilation.

Clean the motor and and ensure free air circulation.

One motor phase may be open.

Check the connection.

Earth fault

Identify and repair.

Asymmetric supply voltage to motor terminal

Check the cables and connections.

Vibrating fan

Loose motor fixing

Tighten the fixing screws and check the alignment.

Unbalanced fan blade/Fan blades misaligned

IEC-fan: Balance the blade or change it.

EC-fan: Change the fan unit.

Faulty bearings

IEC-fan: Change the motor.

EC-fan: Change the fan unit.

3-phase motor running as single phase

Check the connections.

Too big axial play

Check the bearings.

Abrasive noise in fan

Fan blade is chafing against fan collar.

Check the motor centering and fixing.

Motor ventilator is chafing against the cover.

Repair the fan or cover.

Ventilator hits on insulation.

Prevent the touch.

Motor has loosened from its fixing.

Tighten the fixing bolts and rebalance the fan.

Exceptionally heavy noise of running

Air gap not centralized

Check the impeller placement and bearings.