KOJA 0603, Instruction For Operation And Maintenance

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AIR HANDLING UNIT FUTURE
INSTRUCTIONS FOR OPERATION AND MAINTENANCE
Fan section, motors and frequency converters
34 V. 2.0 2017-02-13
WARNING
Electrical connections must be made by a qualified and authorized electrician only. Before
starting any installation and maintenance work on the electrical device, make absolutely
sure that the device is de-energized. After switching off the power, wait at least five
minutes to allow dangerous voltages to discharge from the devices. Electrical devices
should be inspected every six months. Any deficiencies and faults must be rectified
immediately.
WARNING
Due to functional reasons, fans/motors may start and stop automatically without warning.
This may happen, for example, after a power outage or malfunction.
WARNING
If the units have been in storage for an extended time, make sure that there is no moisture
in the link boxes of the motors.
12.1. Short circuit motors
Depending on the model selected, the three-stage short circuit motors used by Koja comply with IE2 or IE3
class efficiency requirements. The motors’ maximum permissible ambient temperature during use is + 40 ˚C.
If the ambient temperature exceeds this, the motor load must be decreased. For more information about the
temperature range, refer to the manufacturer’s instructions. The motors are also available with separate therm -
istors or temperature switches. The motors are suitable for frequency converter control.
Most motors have sealed bearings. Motors of frame size IEC-160 and the larger IE3 classified motors have open
bearings over the transitional phase (up to the beginning of 2015). Lubrication is carried out according to the
separate lubrication instructions supplied with the motor.
Short circuit motors have a ready-connected screened motor cable with number- or colour-coded conductors.
See the figure below for a principle of frequency converter connections to the supply mains and building auto -
mation system, as well as motor connections to the frequency converter. The frequency converter is also avail -
able ready-connected with the motor cable connected to the frequency converter and the frequency converter
fixed to the fan section casing.
L1
F1
AC 3 x 400V
VAK
f1
f2
M
3~
L2
L3
PE
L1
L2
L3
PE
U
V
W
PE
U1
V1
W1
PE
A
A. Frequency converter
PE min 10mm
2
or two wires
The frequency converter control cable must be screened. The control cable screen is connected on the frequen -
cy converter end only. A service switch must be installed on the frequency converter supply cable.
If the short circuit motor frequency converter is ordered ready-parameterised, it comes complete with motor
plate values, a current limit, acceleration/deceleration ramps (60 s), minimum frequency instructions (10 Hz)