Short Cycle Protection - Danfoss VLT FC 102 Programming Manual

Parameter Descriptions
22-60 Broken Belt Function
Selects the action to be performed if the broken-belt condition is
detected.
Option:
3 3
[0] Off
*
[1] Warning
[2] Trip
22-61 Broken Belt Torque
Range:
10 %
*
22-62 Broken Belt Delay
Range:
10 s
208
Function:
NOTICE
Do not set
parameter 14-20 Reset Mode to
[13] Infinite auto reset when
parameter 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
For frequency converters with
constant-speed bypass.
If an automatic bypass
function starts the bypass at
persistent alarm conditions,
disable the bypass's automatic
bypass function if [2] Alarm or
[3] Man. Reset Alarm is selected
as the broken-belt function.
The frequency converter continues
to run, but activates a broken-belt
warning (warning 95, Broken belt). A
frequency converter digital output
or a serial communication bus can
communicate a warning to other
equipment.
The frequency converter stops
running and activates a broken-belt
alarm (alarm 95, Broken belt). A
frequency converter digital output
or a serial communication bus can
communicate an alarm to other
equipment.
Function:
[0 - 100 %] Sets the broken-belt torque as a
percentage of the rated motor
torque.
Function:
[0 - 600 s] Sets the time for which the broken
belt conditions must be active
before carrying out the action
Danfoss A/S © 10/2019 All rights reserved.
®
VLT HVAC Drive FC 102
22-62 Broken Belt Delay
Range:

3.20.6 22-7* Short Cycle Protection

When controlling refrigeration compressors, often there is 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
(parameter 22-77 Minimum Run Time) and any normal start
command (start/jog/freeze) can be overridden by the
interval between starts function (parameter 22-76 Interval
between Starts).
None of the 2 functions are active if hand-on or off modes
have been activated via the LCP. If selecting hand-on or
off, the 2 timers are reset to 0, and do not start counting
until Auto is pressed and an active start command applied.
NOTICE
A coast command or missing run permissive signal
override both minimum run time and interval between
starts functions.
22-75 Short Cycle Protection
Option:
[0]
*
[1]
22-76 Interval between Starts
Range:
Size
related
*
Function:
selected in parameter 22-60 Broken
Belt Function.
Function:
Disabled Timer set in parameter 22-76 Interval
between Starts is disabled.
Enabled Timer set in parameter 22-76 Interval
between Starts is enabled.
Function:
[ par. 22-77 - Sets the minimum time between 2
3600 s] starts. Any normal start command
(start/jog/freeze) is disregarded until
the timer has expired.
M0010001