Danfoss VLT HVAC Drive FC 131 Programming Manual page 174

VLT® HVAC Drive FC 131
Programming Guide
Table 422: Option:
[0] Trip+reset, critical If this mode is selected, the drive continues to run, ignoring most alarms, even if doing so may dam-
alarms age the drive. Critical alarms are alarms that cannot be suppressed but a restart attempt is possible
(infinity automatic reset).
[1] Trip, crit. alarms In case of a critical alarm, the drive trips and does not auto-restart (manual reset).
[2] Trip, all alarms/ It is possible to test the operation of fire mode, but all alarm states are activated normally (manual
test reset).
4.18.2 24-1* Drive Bypass
If a fire mode coast occurs (see parameter 24-00 FM Function), the drive includes a feature that can automatically activate an external
electro-mechanical bypass.
The bypass switches the motor to operation directly on line. One of the digital outputs or relays in the drive activates the external
bypass, when programmed in parameter group 5-3* Digital Outputs or parameter group 5-4* Relays.
The drive bypass cannot be deactivated if in fire mode. It is deactivated only by either removing the fire mode command signal or
the supply to the drive.
When the drive bypass function is activated, the display on the LCP shows the status message Drive bypass. This message has a
higher priority than the fire mode status messages. When the automatic drive bypass function is enabled, it cuts in the external
bypass according to the following illustration.
A lar m A ut o R esets
Speed
Oper a tion
A lar m
B ypass
D ela y
T imer
P24-11
ON
R ela y
"B ypass"
OFF
Read the status in the extended status word 2, bit number 24.
24-10 Drive Bypass Function
Default value: [0] Disabled
Conversion index: -
This function allows to disable or enable drive bypass in fire mode.
Table 423: Option:
[0] Disabled
[2] Enabled (Fire Mode only)
24-11 Drive Bypass Delay Time
Default value: 0 s
Conversion index: 0
174 | Danfoss A/S © 2022.05
N O T I C E
A ut o R eset Disabled
On dela y (P5-41)
Parameter type: Option
Data type: u_int8
Disable the function.
If the timer expires before reset attempts have completed, the bypass function operates a trip at
critical alarms, coast, or bypass delay timer.
Parameter type: Range
Data type: u_int16
2-setup: 1 setup
Change during operation: True
2-setup: 1 setup
Change during operation: True
AU370727746889en-000101 / 130R0994
Parameters