Danfoss VLT HVAC Basic Drive FC 101 Programming Manual page 79

Parameters
22-45 Setpoint Boost
Range: Function:
control, it is advantageous to increase
the system pressure before the motor is
stopped. This extends 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 (P
before entering the Sleep Mode.
If setting for 5%, the boost pressure is
P *1.05. The negative values can be
set
used for e.g. cooling tower control
where a negative change is needed.
0.0% [-100.0-100.0%]
*
22-46 Maximum Boost Time
Range: Function:
60 s [0 - Only to be used if 1-00 Configuration Mode is set
*
600 s] for Closed Loop and the integrated PI controller is
used for controlling the pressure.
Set the maximum time for which boost mode is
allowed. If the set time is exceeded, Sleep Mode
will be entered, not waiting for the set boost
pressure to be reached.
22-47 Sleep Speed [Hz]
Range: Function:
0 [ 0 - 400.0 ] Set the speed below which the frequency
*
converter goes into Sleep Mode.
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
15 Hz, 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: Function:
[0] Off
*
[1] Warning The frequency converter continues to run, but
activate a Broken Belt Warning [W95]. A drive
digital output or a serial communication bus can
communicate a warning to other equipment.
[2] Trip The frequency converter stops 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.
®
VLT HVAC Basic Drive FC 101 Programming Guide
NOTICE
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 causes the frequency converter to continuously cycle
between running and stopping when a broken belt
condition is detected.
NOTICE
If the frequency converter is equipped with a constant
)/temperature
set
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 %
22-62 Broken Belt Delay
Range:
10 s
MG18B302 - Rev. 2013-09-02
Function:
[5 - 100 %] Sets the broken belt torque as a percentage
*
of the rated motor torque.
Function:
[0 - 600 Sets the time for which the Broken Belt
*
s] conditions must be active before carrying out
the action selected in 22-60 Broken Belt
Function.
3 3
77