Danfoss VLT HVAC Basic Drive FC 101 Programming Guide

3.5.4 4-6* Speed Bypass
Dene the speed bypass areas for the ramps. 3 frequency
ranges can be avoided.
4-61 Bypass Speed From [Hz]
Array[3]
Range: Function:
0 Hz [ 0 - 500 Hz] Enter the lower limits of the speeds to be
avoided. Some systems call for avoiding
certain output speeds due to resonance
problems in the system.
4-63 Bypass Speed To [Hz]
Array[3]
Range: Function:
0 Hz* [ 0 - 500 Hz] 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.
3.5.5 Semi-Automatic Bypass Speed Set-up
Use the semi-automatic bypass speed set-up to facilitate
the programming of the frequencies to be skipped due to
resonances in the system.
Procedure:
1. Stop the motor.
NOTICE
Adjust the ramp times in parameter 3-41 Ramp 1 Ramp
Up Time and parameter 3-42 Ramp 1 Ramp Down Time.
2. Select [1] Enabled in parameter 4-64 Semi-Auto
Bypass Set-up.
3. Press [Hand On] to start the search for frequency
bands causing resonances. The motor ramps up
according to the ramp set.
NOTICE
Terminal 27 digital input parameter 5-12 Terminal 27
Digital Input has [2] Coast inverse as default setting. If
there is no 24 V to terminal 27, [Hand On] does not start
the motor. If so, connect terminal 12 to terminal 27.
4. When sweeping through a resonance band, press
[OK] on the LCP when leaving the band. The
actual frequency is stored as the rst element in
parameter 4-63 Bypass Speed To [Hz] (array).
Repeat this procedure for each resonance band
identied at the ramp-up (maximum of 3 can be
adjusted).
5. When maximum speed has been reached, the
motor automatically begins to ramp down.
Repeat this procedure when speed is leaving the
resonance bands during the deceleration. The
actual frequencies registered when pressing [OK]
are stored in parameter 4-61 Bypass Speed From
[Hz].
6. When the motor has ramped down to stop, press
[OK]. The parameter 4-64 Semi-Auto Bypass Set-up
automatically resets to o. The frequency
converter stays in hand on mode until [O] or
[Auto On] is pressed.
If the frequencies for a certain resonance band are not
registered in the right order (frequency values stored in
parameter 4-63 Bypass Speed To [Hz] are ≥ the values in
parameter 4-61 Bypass Speed From [Hz]), or if they do not
have the same numbers of registrations for the
parameter 4-61 Bypass Speed From [Hz] and
parameter 4-63 Bypass Speed To [Hz], all registrations are
canceled and the following message is shown: Collected
speed areas overlapping or not determined. Press [Cancel] to
abort.
4-64 Semi-Auto Bypass Set-up
Option: Function:
[0] * O
[1] Enable If this option is selected, speed ranges are automat-
ically swept to identify bands of resonances.
Parameters
VLT
®
HVAC Basic Drive FC 101
46 Danfoss A/S © 04/2018 All rights reserved. MG18B502
33

Danfoss VLT HVAC Basic Drive FC 101 Specifications

General

Brand	Danfoss
Model	VLT HVAC Basic Drive FC 101
Category	DC Drives
Language	English