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.
WARNING:

Before moving to the solution, ensure that the unit is in safe condition. See Residual risks.