3.22 Main Menu - Application Functions 2 - Group 24
3.22.1 24-0* Fire Mode
CAUTION
Please note the frequency converter is only one 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 over pressure and result in damage to VLT
®
HVAC Drive system and components, hereunder 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 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 will show a status message “Fire Mode” and a warning “Fire Mode”.
Once the Fire Mode is again deactivated, the status messages will disappear and the warning will be replaced by the
warning “Fire M Was Active”. This message can only be reset by power-cycling the frequency converter supply. If, whilst the
frequency converter is active in Fire Mode, a warranty-affecting alarm (see
24-09 Fire Mode Alarm Handling
) should occur,
display will show 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* and parameter group 5-4*.
“Fire M was Active” messages can also be accessed in the warning word via serial communication. (See relevant documen-
tation).
The status messages “Fire Mode” can be accessed 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
+
+
Log
An overview of events related to Fire Mode can be viewed in the Fire Mode log, parameter group 18-1*, or via the Alarm
Log button on the LCP.
The log will include up to 10 of the latest events. Warranty Affecting Alarms will have a higher priority as the two other
types of events.
The log cannot be reset!
Following events are logged:
*Warranty affecting alarms (see
24-09 Fire Mode Alarm Handling
, Fire Mode Alarm Handling)
*Fire Mode activated
*Fire Mode deactivated
All other alarms occurring while Fire Mode activated will be logged as usual.
Parameter Description
VLT
®
HVAC Drive Programming Guide
MG.11.CC.02 - VLT
®
is a registered Danfoss trademark
171
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