IMO BKF
Maintenance/troubleshooting/cleaning
BKF 16.08.2021 13
ATTENTION
Hazard with risk of additional costs
In case of speed control via frequency converter - min. 20 Hz ÷ max. 50 Hz (rsp. 60 Hz, if declared for 60
Hz), it is recommended use of combination of frequency converter and appropriate all-pole sine filter (or
dU/dt filter). It is particularly important, if the supply cable is long, but also to reduce the motor noise.
Filters may only be abandoned, if proven, that the voltage peaks on the connection terminals of the fan
are inside stress category B-C (moderate-severe) up to EN 60034-18-41. Practically, the peaks shall be
lower than limits U
LL
2550 V, U
LG
1800 V and the rise time longer than 0,5 μs. Not observing this, the
motor life time could be shorter. See also Appendix 2, Motor range.
The motors cannot be voltage-controlled! The motor can overheat due to increased current at lower
voltage.
WARNING
Hazard from electrical voltage and flying parts!
Errors occurring can lead to personal and/or property damage!
Switch the fan immediately off as planned:
In cases of a non-typical noise from bearings, vibrations, pressure pulsation.
In case of overcurrent, overvoltage or temperature (nameplate). Then try to find the reason - see
chapter 10.
10 Maintenance/troubleshooting/cleaning
WARNING
Hazard from electrical voltage!
Trouble setting and service only by a trained electrician or trained and instructed qualified personnel!
Observe rules for safe work at maintenance/troubleshooting, cleaning and service!
Observe 5 safety rules for the electrical expert!
- disconnect from the power supply (all-pole),
- prevent switching on again,
- test absence of voltage,
- earthing and short-circuiting,
- protect adjacent live parts by covers and barriers and fit a suitable warning notice.
DANGER
Hazard from injurie from rotating parts, if not covered with protective grid! Hazard from injurie from
rotating parts, when open revision cover!
The outlet protective grid is available as accessory. If needed to remove protective grids/revision cover
temporarily, assure:
Electrical circuit must be interrupted and secured against restarting.
Impeller must stand still.
Immediately after finished work fix protective grids.