Operating instructions
NOTE
Automatic restart will reset the alarm and start the
system again.
NOTE
Do not set par. 14-20 Reset Mode, to [13] Infinite auto
reset, when par. 22-50 End of Curve Function is set to [2]
Alarm. Doing so will cause the drive to continuously
cycle between running and stopping when a End of
Curve condition is detected.
NOTE
If the drive is equipped with a constant speed bypass
with an automatic bypass function that starts the bypass
if the drive experiences a persistent alarm condition, be
sure to disable the bypass’s automatic bypass function,
if [2] Alarm or [3] Man. Reset Alarm is selected as the End
of Curve Function.
22-51 End of Curve Delay
Range: Function:
10 s
*
[0 - 600
s]
When an End of Curve condition is detected, a
timer is activated. When the time set in this
parameter expires, and the End of Curve
condition has been steady in the entire period,
the function set in par. 22-50 End of Curve
Function will be activated. If the condition
disappears before the timer expires, the timer will
be reset.
3.20.5 22-6* Broken Belt Detection
The Broken Belt Detection can be used in both closed and
open loop systems for pumps, fans and compressors. If the
estimated motor torque is below the broken belt torque value
(par. 22-61 Broken Belt Torque) and the frequency converter
output frequency is above or equal to 15 Hz, the broken belt
function (par. 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 drive will continue 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 drive 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.
NOTE
Do not set par. 14-20 Reset Mode, to [13] Infinite auto
reset, when par. 22-60 Broken Belt Function is set to [2]
Trip. Doing so will cause the drive to continuously cycle
between running and stopping when a broken belt
condition is detected.
NOTE
If the drive is equipped with a constant speed bypass
with an automatic bypass function that starts the bypass
if the drive 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: Function:
10 %
*
[0 - 100 %] Sets the broken belt torque as a percentage
of the rated motor torque.
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 par. 22-60 Broken Belt
Function.
3.20.6 22-7* Short Cycle Protection
When controlling refrigeration compressors, often there will
be a need for limiting the numbers of starts. One way to do
this is to ensure a minimum run time (time between a start
and a stop) and a minimum interval between starts.
This means that any normal stop command can be overridden
by the Minimum Run Time function (par. 22-77 Minimum Run
Time) and any normal start command (Start/Jog/Freeze) can
be overridden by the Interval Between Starts function
(par. 22-76 Interval between Starts).
None of the two functions are active if Hand On or Off modes
have been activated via the LCP. If selecting Hand On or Off,
the two timers will be reset to 0, and not start counting until
Auto is pressed and an active start command applied.
NOTE
A Coast command or missing Run Permissive signal will
override both Minimum Run Time and Interval Between
Starts functions.
22-75 Short Cycle Protection
Option: Function:
[0]
*
Disabled Timer set in par. 22-76 Interval between Starts is
disabled.
[1] Enabled Timer set in par. 22-76 Interval between Starts is
enabled.
Parameter Description
VLT
®
HVAC Drive Programming Guide
MG.11.CA.02 - VLT
®
is a registered Danfoss trademark 147
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