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
) 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 group5-3* 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
, 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
162
MG.11.CB.02 - VLT
®
is a registered Danfoss trademark
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