Broken Belt Detection - Danfoss VLT HVAC Basic Drive Programming Manual

Parameters
22-45 Setpoint Boost
Range:
0.0 [-100.0 -
% 100.0 %]
*
3 3
22-46 Maximum Boost Time
Range:
60 s [0 - 600
*
s]
22-47 Sleep Speed [Hz]
Range:
0.0 s [0.0 - 400.0 s] Set the speed below which the frequency
*

3.15.2 22-6* Broken Belt Detection

The Broken Belt Detection can be used in both closed and
open loop systems for pumps and fans. If the estimated
motor torque (current) is below the broken belt torque
(current) value (22-61 Broken Belt Torque) and the frequency
converter output frequency is above or equal to 15Hz,
22-60 Broken Belt Function is performed
22-60 Broken Belt Function
Selects the action to be performed if the Broken Belt condition is
detected.
Option:
[0] Off
*
[1] Warning The frequency converter will continue to run, but
[2] Trip
70
VLT HVAC Basic Drive Programming Guide
Function:
Only to be used if 1-00 Configuration Mode, is set
for Closed Loop and the integrated PI controller is
used. In systems with e.g. constant pressure
control, it is advantageous to increase the system
pressure before the motor is stopped. This will
extend the time in which the motor is stopped
and help to avoid frequent start/stop.
Set the desired over pressure/temperature in
percentage of set point for the pressure (Pset)/
temperature before entering the Sleep Mode.
If setting for 5%, the boost pressure will be
Pset*1.05. The negative values can be used for e.g.
cooling tower control where a negative change is
needed.
Function:
Only to be used if 1-00 Configuration Mode is set
for Closed Loop and the integrated PI controller is
used for controlling the pressure.
Set the maximum time for which boost mode will
be allowed. If the set time is exceeded, Sleep
Mode will be entered, not waiting for the set
boost pressure to be reached.
Function:
converter will go into Sleep Mode.
Function:
activate a Broken Belt Warning [W95]. A drive
digital output or a serial communication bus can
communicate a warning to other equipment.
The frequency converter will stop running and
activate a Broken Belt alarm [A 95]. A drive digital
output or a serial communication bus can
communicate an alarm to other equipment.
MG.18.B1.02 - VLT
NOTE
Do not set 14-20 Reset Mode, to [13] Infinite auto reset, when
22-60 Broken Belt Function is set to [2] Trip. Doing so will
cause the frequency converter to continuously cycle
between running and stopping when a broken belt
condition is detected.
NOTE
If the frequency converter is equipped with a constant speed
bypass with an automatic bypass function that starts the
bypass if the frequency converter experiences a persistent
alarm condition, be sure to disable the bypass's automatic
bypass function, if [2] Trip is selected as the Broken Belt
Function.
22-61 Broken Belt Torque
Range:
10 % [5 - 100 %] Sets the broken belt torque as a percentage
*
22-62 Broken Belt Delay
Range: Function:
10 s [0 - 600 s] Sets the time for which the Broken Belt
*
conditions must be active before carrying out
the action selected in 22-60 Broken Belt
Function.
®
is a registered Danfoss trademark
Function:
of the rated motor torque.