Danfoss VLT Series Programming Manual page 155

Parameter Description
22-51 End of Curve Delay
Range:
10 s [0 - 600
*
s]
3 3
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 (22-61 Broken Belt Torque) and the frequency
converter output frequency is above or equal to 15 Hz, the
broken belt function (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 drive will continue to run, but activate a
[2] Trip
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 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:
10 % [0 - 100 %] Sets the broken belt torque as a percentage
*
154
VLT
Function:
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 22-50 End of Curve Function
will be activated. If the condition disappears
before the timer expires, the timer will be reset.
Function:
Broken Belt Warning [W95]. A drive digital output
or a serial communication bus can communicate
a warning to other equipment.
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.
Function:
of the rated motor torque.
MG.11.CC.02 - VLT
®
HVAC Drive Programming Guide
22-62 Broken Belt Delay
Range:
10 s [0 - 600 s] Sets the time for which the Broken Belt
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
(22-77 Minimum Run Time) and any normal start command
(Start/Jog/Freeze) can be overridden by the Interval
Between Starts function (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:
[0] Disabled Timer set in 22-76 Interval between Starts is
*
[1] Enabled Timer set in 22-76 Interval between Starts is
22-76 Interval between Starts
Range:
Size related
*
®
is a registered Danfoss trademark
Function:
conditions must be active before carrying out
the action selected in 22-60 Broken Belt
Function.
Function:
disabled.
enabled.
Function:
[ par. 22-77 Sets the time desired as minimum
- 3600 s] time between two starts. Any
normal start command (Start/Jog/
Freeze) will be disregarded until the
timer has expired.