Technical information

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
documentation).
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.
NOTE
During Fire Mode operation all stop commands to the
frequency converter will be ignored, including Coast/Coast
inverse and External Interlock. However, if your frequency
converter incorporates “Safe-Stop”, this function is still
active. See Section “How to Order / Ordering Form Type
Code”.
Parameter Description
VLT
®
HVAC Drive Programming Guide
MG11CD02 - VLT
®
is a registered Danfoss trademark 169
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