Danfoss VLT HVAC Series User Manual

3.20.5 22-6* Broken Belt Detection
Broken belt detection can be used in both closed-loop 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 adjustable frequency drive 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
Option: Function:
Selects the action to be performed if the broken belt condition is detected.
[0] * OFF
[1] Warning
[2] Trip
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.
22-76 Interval between Starts
Range: Function:
par. 22-77
s*
[par. 22-77 - 3600 s] Sets the time desired as minimum time between two starts. Any normal start command (Start/Jog/
Freeze) will be disregarded until the timer has expired.
3 Parameter Description VLT
®
HVAC Drive Programming Guide
3-206 MG.11.C6.22 - VLT
®
is a registered Danfoss trademark
3

Danfoss VLT HVAC Series Specifications

General

Protection Features	Overcurrent, Overvoltage, Undervoltage, Overtemperature, Short circuit
Communication Interfaces	Profibus, Ethernet
Cooling Method	Forced convection
Ambient Temperature	-10°C to +40°C
Enclosure Rating	IP20, IP21, IP55
Output Voltage	0 - 100% of supply voltage