Operating instructions

4-61 Bypass Speed From [Hz]
Array [4]
Range: Function:
Application
dependent
*
[Application
dependant]
Some systems call for avoiding
certain output speeds due to
resonance problems in the
system. Enter the lower limits of
the speeds to be avoided.
4-62 Bypass Speed To [RPM]
Array [4]
Range: Function:
Application
dependent
*
[Application
dependant]
Some systems call for avoiding
certain output speeds due to
resonance problems in the
system. Enter the upper limits
of the speeds to be avoided.
4-63 Bypass Speed To [Hz]
Array [4]
Range: Function:
Application
dependent
*
[Application
dependant]
Some systems call for avoiding
certain output speeds due to
resonance problems in the
system. Enter the upper limits
of the speeds to be avoided.
3.6.4 Semi-Automatic Bypass Speed Set-up
The Semi-Automatic Bypass Speed Setup can be used to facili-
tate the programming of the frequencies to be skipped due to
resonances in the system.
The following process is to be carried out:
1. Stop the motor.
2. Select Enabled in par. 4-64 Semi-Auto Bypass Set-up.
3. Press Hand On on the LCP to start the search for
frequency bands causing resonances. The motor will
ramp up according to the ramp set.
4. When sweeping through a resonance band, press OK
on the LCP when leaving the band. The actual
frequency will be stored as the first element in
par. 4-62 Bypass Speed To [RPM] or par. 4-63 Bypass
Speed To [Hz] (array). Repeat this for each resonance
band identified at the ramp-up (maximum four can
be adjusted).
5. When maximum speed has been reached, the motor
will automatically begin to ramp-down. Repeat the
above procedure when speed is leaving the
resonance bands during the deceleration. The actual
frequencies registered when pressing OK will be
stored in par. 4-60 Bypass Speed From [RPM] or
par. 4-61 Bypass Speed From [Hz].
6. When the motor has ramped down to stop, press OK.
The par. 4-64 Semi-Auto Bypass Set-up will automati-
cally reset to Off. The frequency converter will stay in
Hand mode until Off or Auto On are pressed on the
LCP.
If the frequencies for a certain resonance band are not
registered in the right order (frequency values stored in By
Pass Speed To are higher than those in By Pass Speed From) or if
they do not have the same numbers of registrations for the By
Pass From and By Pass To, all registrations will be cancelled and
the following message is displayed: Collected speed areas
overlapping or not completely determined. Press [Cancel] to
abort.
4-64 Semi-Auto Bypass Set-up
Option: Function:
[0] * Off No function
[1] Enabled Starts the Semi-Automatic Bypass set-up and
continue with the procedure described above.
Parameter Description
VLT
®
HVAC Drive Programming Guide
MG.11.CA.02 - VLT
®
is a registered Danfoss trademark 57
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