Kruger ADA Series - Page 5

Fan does not start or operate
Possible cause
Remedy
Electrical Supply
 Blown fuses
 Electricity turned off
 Wrong voltage
 Failure of one or two phases
 Low voltage, excessive line drop or inadequate wire
size
 Check fuses/circuit breakers
 Check for switched off or disconnected
 Check for correct power supply
 Check for correct power supply
 Check for correct wire size
Motor
 Motor not correctly connected
 Load inertia too large for motor
 Motor protection unit or switch are stopping as
temperature are too high
 Motor too small and overload protector has broken
circuit
 Connect the motor according to the motor label
 Change motor
 Reduce temperatures, check and change insulation
class, increase motor rating
 Change motor
Drive System
 Broken belts
 Loose pulleys
 Replace belt
 Tighten pulley
Excessive air flow
Possible cause
Remedy
Fan
 Excessive rotational fan speed
 Reduce fan speed
Duct System
 Pressure resistance offered by the system lower than
the design value
Gas Density
 Gas density higher than the design value
High power absorption
Possible cause
Remedy
Impeller
 Air flow already rotating in the opposite direction to
the fan rotation direction
 Backward curved impeller installed backwards
Motor
 Faults in the motor windings
 Motor power supply voltage lower than the value
indicated on the identification plate
 Replace motor
 Check with motor supplier
Fan
 Forward curved or backward blade fan operating below
design pressures.
System
 Oversized ductwork
 Filter(s) left out
 Access door are open
 Face and by-pass dampers oriented so coil dampers
are open at same time by-pass dampers are open
 Redesign ductwork
 Add in filter(s)
 Close access door
Gas Density
 Calculated horsepower requirements based on light
gas (eg. High temperature) but actual gas is heavy
(eg. Cold start up)
Fan selection
 Fan not selected at efficient point of rating
 Check selection