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3.22. Main Menu - Application Functions 2 - Group 24
3.22.1. 24-0* Fire Mode
NB!
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 may cause over pressure
and result in damage to VLT HVAC Drive system and components, hereunder dampers and air ducts. The frequency
converter itself may be damaged and it may cause damage or fire. Danfoss accepts no responsibility for errors, mal-
functions 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 par 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 parameter 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 par 5-3* and 5-4*.
“Fire M was Active” messages can also be accessed in the warning word via serial communication. (See relevant documentation).
The status messages “Fire Mode” can be accessed via the extended status word.
Message
Type
LCP
Digital Out/Relay
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 18-1*, or via the Alarm Log button on the Local Control Panel.
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 parameter 24-09, Fire Mode Alarm Handling)
*Fire Mode activated
*Fire Mode deactivated
All other alarms occurring while Fire Mode activated will be logged as usual.
3. Parameter Description
VLT
®
HVAC Drive Programming Guide
202
MG.11.C5.02 - VLT
®
is a registered Danfoss trademark
3