3.22 Parameters: 24-** Application Functions 2
3.22.1 24-0* Fire Mode
CAUTION
Note the frequency converter is only 1 component of the VLT
®
HVAC Drive system. Correct function of fire mode
depends on the correct design and selection of system components. Ventilation systems working in life safety
applications have to be approved by the local fire authorities. Non-interruption of the frequency converter due to fire
mode-operation could cause overpressure and result in damage to VLT
®
HVAC Drive system and components, including
dampers and air ducts. The frequency converter itself could be damaged and it may cause damage or fire. Danfoss
accepts no responsibility for errors, malfunctions personal injury, or any damage to the frequency converter itself or
components herein, VLT
®
HVAC Drive systems and components herein, or other property when the frequency converter
has been programmed for fire mode. In no event shall Danfoss be liable to the end user or any other party for any
direct or indirect, special or consequential damage or loss suffered by such party, which has occurred due to the
frequency converter being programmed and operated in fire mode.
Background
Fire mode is for use in critical situations, where it is imperative for the motor to keep running, regardless of the frequency
converter’s normal protective functions. These could be ventilation fans in tunnels or stairwells for instance, where
continued operation of the fan facilitates safe evacuation of personnel in the event of a fire. Some selections of the fire
mode function cause alarms and trip conditions to be disregarded, enabling the motor to run without interruption.
Activation
Fire mode is activated only via digital Input terminals. See parameter group
5-1* Digital Inputs
.
Messages in display
When fire mode is activated, the display shows a status message
Fire Mode
and a warning
Fire Mode
.
Once the fire mode is again deactivated, the status messages disappears and the warning is replaced by the warning
Fire M
Was Active
. This message can only be reset by power-cycling the frequency converter supply. If a warranty-affecting alarm
(see
parameter 24-09 Fire Mode Alarm Handling
) should occur while the frequency converter is active in fire mode, the
display shows the warning Fire M Limits Exceeded.
Digital and relay outputs can be configured for the status messages
Fire Mode Active
and the warning
Fire M Was Active
. See
parameter group
5-3* Digital Outputs
and parameter group
5-4* Relays
.
Fire M was Active
messages can also be accessed in the warning word via serial communication. (See relevant documen-
tation).
Access the status messages
Fire Mode
via the extended status word.
Message
Type
LCP
Messages in
display
Warning word 2
Ext. status word 2
Fire Mode
Status
+
+
+ (bit 25)
Fire Mode
Warning
+
Fire M was Active
Warning
+
+
+ (bit 3)
Fire M Limits Exceeded
Warning
+
+
Table 3.27 Messages in Display
Parameter Descriptions
VLT
®
HVAC Drive FC 102
184
Danfoss A/S © 03/2015 All rights reserved.
MG11CE02
3
3