Trox Technik FKA2-EU User manual

Fire damper
Type FKA2-EU
Installation and operating manual
Read the instructions prior to performing any task!
according to Declaration of Performance
DoP / FKA2-EU / DE / 002
GB/en
Short version
This is a content-reduced short version. The full version is available at
www.trox-docs.com.

A00000076523, 3, GB/en
Translation of the original
© 2020
TROX GmbH
Heinrich-Trox-Platz
47504 Neukirchen-Vluyn, Germany
Germany
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
Internet: http://www.troxtechnik.com
01/2021
Fire damper Type FKA2-EU2

General information
About this manual
This operating and installation manual enables oper-
ating or service personnel to correctly install the TROX
product described below and to use it safely and effi-
ciently.
This operating and installation manual is intended for
use by fitting and installation companies, in-house tech-
nicians, technical staff, instructed persons, and qualified
electricians or air conditioning technicians.
It is essential that these individuals read and fully under-
stand this manual before starting any work. The basic
prerequisite for safe working is to comply with the safety
notes and all instructions in this manual.
The local regulations for health and safety at work and
general safety regulations also apply.
This manual must be given to the system owner when
handing over the system. The system owner must
include the manual with the system documentation. The
manual must be kept in a place that is accessible at all
times.
Illustrations in this manual are mainly for information
and may differ from the actual design.
Copyright
This document, including all illustrations, is protected by
copyright and pertains only to the corresponding
product.
Any use without our consent may be an infringement of
copyright, and the violator will be held liable for any
damage.
This applies in particular to:
Publishing content
Copying content
Translating content
Microcopying content
Saving content to electronic systems and editing it
TROX Technical Service
To ensure that your request is processed as quickly as
possible, please keep the following information ready:
Product name
TROX order number
Delivery date
Brief description of the fault
Online www.troxtechnik.com
Phone [phone]
Limitation of liability
The information in this manual has been compiled with
reference to the applicable standards and guidelines,
the state of the art, and our expertise and experience of
many years.
The manufacturer does not accept any liability for dam-
ages resulting from:
Non-compliance with this manual
Incorrect use
Operation or handling by untrained individuals
Unauthorised modifications
Technical changes
Use of non-approved replacement parts
The actual scope of delivery may differ from the infor-
mation in this manual for bespoke constructions, addi-
tional order options or as a result of recent technical
changes.
The obligations agreed in the order, the general terms
and conditions, the manufacturer's terms of delivery,
and the legal regulations in effect at the time the con-
tract is signed shall apply.
We reserve the right to make technical changes.
Warranty claims
The provisions of the respective delivery terms apply to
warranty claims. For purchase orders placed with TROX
GmbH, these are the regulations in section "Vl. War-
ranty claims" of the Delivery and Payment Terms of
TROX GmbH, see www.trox.de/en/ .
General information
Fire damper Type FKA2-EU 3

Safety notes
Symbols are used in this manual to alert readers to
areas of potential hazard. Signal words express the
degree of the hazard.
Comply with all safety instructions and proceed carefully
to avoid accidents, injuries and damage to property.
DANGER!
Imminently hazardous situation which, if not avoided,
will result in death or serious injury.
WARNING!
Potentially hazardous situation which, if not avoided,
may result in death or serious injury.
CAUTION!
Potentially hazardous situation which, if not avoided,
may result in minor or moderate injury.
NOTICE!
Potentially hazardous situation which, if not avoided,
may result in property damage.
ENVIRONMENT!
Environmental pollution hazard.
Tips and recommendations
Useful tips and recommendations as well as informa-
tion for efficient and fault-free operation.
Safety notes as part of instructions
Safety notes may refer to individual instructions. In this
case, safety notes will be included in the instructions
and hence facilitate following the instructions. The
above listed signal words will be used.
Example:
1. Loosen the screw.
2.
CAUTION!
Danger of finger entrapment when closing
the lid.
Be careful when closing the lid.
3. Tighten the screw.
Specific safety notes
The following symbols are used in safety notes to alert
you to specific hazards:
Warning signs Type of danger
Warning – danger zone.
General information
Fire damper Type FKA2-EU4

1 Safety ................................................................ 6
1.1 General safety notes ................................. 6
1.2 Correct use ................................................ 6
1.3 Qualified staff ............................................. 6
2 Technical data .................................................. 7
2.1 General data .............................................. 7
2.2 FKA2-EU with fusible link .......................... 9
2.3 FKA2-EU with spring return actuator ....... 12
2.4 FKA2-EU with spring return actuator and
duct smoke detector ................................ 19
2.5 FKA2-EU with fusible link and cover grille
used as an air transfer unit ...................... 20
2.6 FKA2-EU with spring return actuator and
duct smoke detector used as an air
transfer damper ....................................... 21
3 Supply package, transport and storage ...... 22
4 Installation ...................................................... 23
4.1 Installation situations ............................... 23
4.2 Safety notes regarding installation .......... 27
4.3 General installation information ............... 27
4.4 Solid walls ............................................... 38
4.4.1 Mortar-based installation ...................... 39
4.5 Lightweight partition walls and compart-
ment walls with metal support structure .. 40
4.5.1 Dry mortarless installation with installa-
tion kit ES ............................................. 44
4.5.2 Dry mortarless installation with fire batt
............................................................... 47
4.6 Fixing the fire damper .............................. 50
4.6.1 General ................................................. 50
4.6.2 Suspending fire dampers installed
remote from solid walls and ceiling slabs
............................................................... 51
4.6.3 Fixing the damper when a fire batt is
used ...................................................... 52
5 Electrical connection .................................... 55
5.1 Limit switches (fire dampers with fusible
link) .......................................................... 55
5.2 Spring return actuator .............................. 55
5.3 Spring return actuator and duct smoke
detector RM-O-3-D .................................. 55
6 Functional test ............................................... 56
6.1 Fire damper with fusible link .................... 56
6.1.1 Fusible link – size 1 .............................. 56
6.1.2 Fusible link – size 2 and 3 .................... 57
6.2 Fire damper with spring return actuator .. 60
6.2.1 Spring return actuator – BFL... / BFN...
............................................................... 60
6.3 Functional test with automatic control unit
.................................................................. 62
7 Commissioning .............................................. 63
8 Index................................................................ 64
Table of contents
Fire damper Type FKA2-EU 5

1 Safety
1.1 General safety notes
Sharp edges, sharp corners and thin sheet metal
parts
CAUTION!
Danger of injury from sharp edges, sharp cor-
ners and thin sheet metal parts!
Sharp edges, sharp corners and thin sheet metal
parts may cause cuts or grazes.
– Be careful when carrying out any work.
– Wear protective gloves, safety shoes and a hard
hat.
Electrical voltage
DANGER!
Danger of electric shock! Do not touch any live com-
ponents! Electrical equipment carries a dangerous
electrical voltage.
– Only skilled qualified electricians are allowed to
work on the electrical system.
– Switch off the power supply before working on
any electrical equipment.
1.2 Correct use
The fire damper is used as an automatic shut-off
device to prevent fire and smoke from spreading
through ducting.
The fire damper is suitable for supply and extract air
in HVAC systems.
The fire damper may be used in potentially explo-
sive atmospheres if appropriate special accessories
are used with it and if the product bears the CE con-
formity marking according to Directive 94/9/EC. Fire
dampers for use in potentially explosive atmos-
pheres are marked for the zones for which they
have been approved.
Operation of the fire dampers is allowed only in
compliance with installation regulations and the
technical data in this installation and operating
manual.
Modifying the fire damper or using replacement
parts that have not been approved by TROX is not
permitted.
Incorrect use
WARNING!
Danger due to incorrect use!
Incorrect use of the fire damper can lead to dan-
gerous situations.
Never use the fire damper
– without specially approved attachments in areas
with potentially explosive atmospheres
– as a smoke control damper
– outdoors without sufficient protection against the
effects of weather
– in atmospheres where chemical reactions,
whether planned or unplanned, may cause
damage to the fire damper or lead to corrosion
1.3 Qualified staff
WARNING!
Danger of injury due to insufficiently qualified
individuals!
Incorrect use may cause considerable injury or
damage to property.
– Only specialist personnel must carry out work.
Personnel:
Skilled qualified electrician
Specialist personnel
Skilled qualified electrician
Skilled qualified electricians are individuals who have
sufficient professional or technical training, knowledge
and actual experience to enable them to work on elec-
trical systems, understand any potential hazards related
to the work under consideration, and recognise and
avoid any risks involved.
Specialist personnel
Specialist personnel are individuals who have sufficient
professional or technical training, knowledge and actual
experience to enable them to carry out their assigned
duties, understand any potential hazards related to the
work under consideration, and recognise and avoid any
risks involved.
Safety
Qualified staff
Fire damper Type FKA2-EU6

2 Technical data
2.1 General data
Nominal sizes B × H 200 × 100 – 1500 × 800 mm *
Casing lengths L 305 and 500 mm
Volume flow rate range Up to 14400 l/s or 51840 m³/h
Differential pressure range Up to 2000 Pa
Temperature range 1, 3 -20 °C to 50 °C
Release temperature 72 °C or 95 °C (for warm air ventilation systems)
Upstream velocity 2≤ 8 m/s with fusible link,
≤ 12 m/s with spring return actuator
Closed blade air leakage EN 1751, Class 2
Casing air leakage EN 1751, Class C; (B + H) ≤ 700, Class B
EC conformity Construction Products Regulation (EU) No. 305/2011
EN 15650 – Ventilation for buildings – Fire dampers
EN 13501-3 – Classification: Fire resistant ducts and fire
dampers 4
EN 1366-2 – Fire resistance tests for installations: Fire
dampers
EN 1751 Ventilation for buildings – Air terminal devices
Declaration of performance DoP / FKA2-EU / DE / 002
1) Temperatures may differ for units with attachments. Details for other applications are available on request.
2) Data applies to uniform upstream and downstream conditions for the fire damper.
3) Condensation and the intake of humid fresh air have to be avoided as otherwise operation will be impaired or not possible.
4) Leakage rate of the fire damper system tested at 300 Pa and 500 Pa negative pressure.
* Damper blade with lip seal for sizes 1 and 2, damper blade with travel stop seal for size 3, see table
Ä 10 .
Technical data
General data
Fire damper Type FKA2-EU 7

Product sticker
Fig. 1: Product sticker (example)
1 CE mark
2 Manufacturer's address
3 Number of the European standard and year of its
publication
4 Notified body
5 The last two digits of the year in which the CE
marking was affixed
6 Year of manufacture
7 No. of the declaration of performance
8 Website from which the DoP can be downloaded
9 Regulated characteristics; the fire resistance class
depends on the application and may vary
10 Type
11 Order number
Technical data
General data
Fire damper Type FKA2-EU8

2.2 FKA2-EU with fusible link
Dimensions and weight
Fig. 2: FKA2-EU with fusible link
B Width of the fire damper (side B)
H Height of the fire damper (side H)
L Length of the fire damper (casing length)
Y Keep clear to provide access for operation
x 75 mm size 1
87 mm size 2 and 3
Installation side
Operating side
Weight of FKA2-EU with fusible link, see table Ä 10 .
Sizes 1 to 3, see table
Ä 10 .
Limit switches
Connecting cable length / cross section 1 m / 3 × 0.34 mm²
Protection level IP 66
Type of contact 1 changeover contact, gold-plated
Maximum switching current 0.5 A
Maximum switching voltage 30 V DC, 250 V AC
Contact resistance approx. 30 mΩ
Technical data
FKA2-EU with fusible link
Fire damper Type FKA2-EU 9

Technical data
FKA2-EU with fusible link
Fire damper Type FKA2-EU10
Weight [kg] for casing length L = 305 [mm] / L = 500 [mm]
1
H
[mm]
B [mm]
200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
100 4/5 5/6 6/8 7/9 8/11 9/12 10/13 – – – – – – –
[A]
150 4/6 5/7 7/9 8/10 9/12 10/13 11/15 – – – – – – –
200 5/7 6/8 7/10 9/12 10/13 11/15 12/16 15/20 16/21 21/27 23/29 24/31 26/32 27/34
250 7/9 8/10 10/12 11/14 12/16 14/18 15/19 16/21 18/23 24/29 25/31 27/33 29/35 30/38
300 8/10 9/12 11/14 12/15 13/17 15/19 16/21 18/23 19/25 26/32 28/34 30/36 32/39 33/41
350 8/11 10/13 11/15 13/17 15/18 16/20 18/22 24/29 26/32 28/34 30/37 32/39 34/42 36/44
400 9/11 11/13 12/16 14/18 16/20 17/22 19/24 26/31 28/34 31/37 33/39 35/42 37/45 39/47
450 10/12 11/14 13/17 15/19 17/21 23/28 26/31 28/34 30/36 33/39 35/42 38/45 40/48 43/50
[B]
500 10/13 12/15 14/18 16/20 18/22 25/30 27/33 30/36 33/39 35/42 36/45 40/48 43/51 46/54
550 – 15/19 18/22 21/26 24/28 26/32 29/35 32/38 35/41 37/44 40/47 43/51 46/54 49/57
600 – 16/20 19/23 22/27 25/30 28/33 31/37 34/40 37/43 40/47 43/50 46/53 49/57 52/60
650 – 17/21 20/25 23/28 27/32 30/35 33/39 36/42 39/46 42/49 45/53 48/56 51/60 55/63
700 – 18/22 21/26 25/30 28/33 31/37 35/41 38/44 41/48 44/52 48/55 51/59 54/63 58/67
750 – 19/23 22/27 26/31 29/35 33/39 36/43 40/47 43/50 47/54 50/58 54/62 57/66 61/70
800 – 20/24 24/28 27/33 31/36 34/40 38/44 42/49 45/53 49/57 53/61 56/65 60/69 64/73
1)Construction with spring return actuator: [A] = Horizontally arranged spring return actuator, [B] = Vertically arranged spring return actuator
Damper blade with lip seal for sizes 1 and 2, damper blade with travel stop seal for size 3.
Sizes
1
2
Sizes
3

Flange holes
Fig. 3: Flange holes L = 305 mm – uneven and even number of holes
Fig. 4: Flange holes L = 500 mm – uneven and even number of holes
B or H [mm] 100
150
200
250
300
350
400
450
500
550
600 650
700
750
800
900
1000
1100
1200
1300
1400
1500
Number of holes
each horizontal side*
–00111223344
Number of holes
each vertical side*
00011122––––
* Number of holes horizontally (B) or vertically (H), but without corner holes; B < 400 mm and H only with
corner holes
Technical data
FKA2-EU with fusible link
Fire damper Type FKA2-EU 11

2.3 FKA2-EU with spring return actuator
Dimensions and weight
Fig. 5: FKA2-EU with Belimo spring return actuator
B Width of the fire damper (side B)
H Height of the fire damper (side H)
L Length of the fire damper (casing length)
[A] Horizontally arranged spring return actuator
[B] Vertically arranged spring return actuator
Y Keep clear to provide access for operation
Installation side
Operating side
Weight of FKA2-EU with fusible link + approx. 1 kg (BFL... and BFN...), see table Ä 10 .
Sizes 1 to 3 and arrangement of the spring return actuator [A] or [B], see table
Ä 10 .
Technical data
FKA2-EU with spring return actuator
Fire damper Type FKA2-EU12

Spring return actuator BFL...
Construction 230-T TR 24-T-ST TR
Supply voltage 230 V AC, 50/60 Hz 24 V AC/DC, 50/60 Hz
Functional range 198 – 264 V AC 19.2 – 28.8 V AC
21.6 – 28.8 V DC
Power rating Spring winding mecha-
nism / hold position
3.5 W / 1.1 W 2.5 W / 0.8 W
Rating 6.5 VA 4 VA
Running time Actuator / spring return < 60 s / < 20 s
Limit switch Type of contact 2 changeover contacts
Switching voltage 5 – 120 V DC / 5 – 250 V AC
Switching current 1 mA – 3 (0.5 inductive) A
Contact resistance < 1 Ω (when new)
IEC protection class / IP protection II / IP 54
Storage temperature / ambient temperature -40 – 55 °C / -30 – 55 °C ¹
Ambient humidity ≤ 95% rh, no condensation
Connecting cable Actuator / limit switch 1 m, 2 × 0.75 mm² / 1 m, 6 × 0.75 mm² (free of halo-
gens)
Spring return actuator type BFL... for size 1.
¹ Up to 75 °C the safe position will definitely be reached.
Technical data
FKA2-EU with spring return actuator
Fire damper Type FKA2-EU 13

Spring return actuator BFN...
Construction 230-T TR 24-T-ST TR
Supply voltage 230 V AC, 50/60 Hz 24 V AC/DC, 50/60 Hz
Functional range 198 – 264 V AC 19.2 – 28.8 V AC
21.6 – 28.8 V DC
Power rating Spring winding mecha-
nism / hold position
5 W / 2.1 W 4 W / 1.4 W
Rating 10 VA (Imax 4 A @ 5 ms) 6 VA (Imax 8.3 A @ 5 ms)
Running time Actuator / spring return < 60 s / < 20 s
Limit switch Type of contact 2 changeover contacts
Switching voltage 5 – 120 V DC / 5 – 250 V AC
Switching current 1 mA – 3 (0.5 inductive) A
Contact resistance < 1 Ω (when new)
IEC protection class / IP protection II / IP 54
Storage temperature / ambient temperature -40 – 55 °C / -30 – 55 °C ¹
Ambient humidity ≤ 95% rh, no condensation
Connecting cable Actuator / limit switch 1 m, 2 × 0.75 mm² / 1 m, 6 × 0.75 mm² (free of halo-
gens)
Spring return actuator type BFN... for size 2 and 3.
¹ Up to 75 °C the safe position will definitely be reached.
Technical data
FKA2-EU with spring return actuator
Fire damper Type FKA2-EU14

Spring return actuator BF...
Construction 230-TN TR 24-TN-ST TR
Supply voltage 230 V AC, 50/60 Hz 24 V AC/DC, 50/60 Hz
Functional range 198 – 264 V AC 19.2 – 28.8 V AC
21.6 – 28.8 V DC
Power rating Spring winding mecha-
nism / hold position
8.5 W / 3 W 7 W / 2 W
Rating 11 VA 10 VA
Running time Actuator / spring return < 120 s / approx. 16 s
Limit switch Type of contact 2 changeover contacts
Switching voltage 5 – 120 V DC / 5 – 250 V AC
Switching current 1 mA ... 6 A
Contact resistance < 100 mΩ
IEC protection class / IP protection II / IP 54 III / IP 54
Storage temperature / ambient temperature -40 – 50 °C / -30 – 50 °C ¹
Ambient humidity ≤ 95% rh, no condensation
Connecting cable Actuator / limit switch 1 m, 2 × 0.75 mm² / 1 m, 6 × 0.75 mm² (free of halo-
gens)
BF actuator optional, weight of FKA2-EU with fusible link + approx. 2 kg
¹ Up to 75 °C the safe position will definitely be reached.
Technical data
FKA2-EU with spring return actuator
Fire damper Type FKA2-EU 15

Dimensions and weight
Fig. 6: FKA2-EU with Siemens spring return actuator
B Width of the fire damper (side B)
H Height of the fire damper (side H)
L Length of the fire damper (casing length)
[A] Horizontally arranged spring return actuator
[B] Vertically arranged spring return actuator
Y Keep clear to provide access for operation
Installation side
Operating side
Weight of FKA2-EU with fusible link + approx. 1.4 kg (GRA... and GNA...), see table Ä 10 .
Sizes 1 to 3 and arrangement of the spring return actuator [A] or [B], see table
Ä 10 .
Technical data
FKA2-EU with spring return actuator
Fire damper Type FKA2-EU16

Spring return actuator GRA...
Construction 326.1E 126.1E
Supply voltage 230 V AC, 50/60 Hz 24 V AC, 50/60 Hz /
24 – 48 V DC
Functional range 198 – 264 V AC 19.2 – 28.8 V AC
19.2 – 57.6 V DC
Power rating Spring winding mechanism 7 VA / 4.5 W 5 VA / 3.5 W
Hold position 3.5 W 2 W
Running time Actuator / spring return 90 s / 15 s
Limit switch Type of contact 2 changeover contacts
Switching voltage 24 – 230 V AC / 12 – 30 V DC
Switching current AC: 6 A (inductive 2 A) / DC: 2 A
IEC protection class / IP protection II / IP 42 or IP 54* III / IP 42 or IP 54*
Storage temperature / ambient temperature -20 to 50 °C / -20 to 50 °C
Ambient humidity < 95% rh, no condensation
Connecting cable Actuator / limit switch 0.9 m, 6 × 0.75 mm² (free of halogens)
Spring return actuator type GRA... for size 1.
*Connecting cable at the bottom
Spring return actuator GNA...
Construction 326.1E 126.1E
Supply voltage 230 V AC, 50/60 Hz 24 V AC, 50/60 Hz /
24 – 48 V DC
Functional range 198 – 264 V AC 19.2 – 28.8 V AC
19.2 – 57.6 V DC
Power rating Spring winding mechanism 7 VA / 4.5 W 5 VA / 3.5 W
Hold position 3.5 W 2 W
Running time Actuator / spring return 90 s / 15 s
Limit switch Type of contact 2 changeover contacts
Switching voltage 24 – 230 V AC / 12 – 30 V DC
Switching current AC: 6 A (inductive 2 A) / DC: 2 A
IEC protection class / IP protection II / IP 42 or IP 54* III / IP 42 or IP 54*
Storage temperature / ambient temperature -20 to 50 °C / -20 to 50 °C
Ambient humidity < 95% rh, no condensation
Connecting cable Actuator / limit switch 0.9 m, 6 × 0.75 mm² (free of halogens)
Spring return actuator type GNA... for sizes 2 and 3.
*Connecting cable at the bottom
Technical data
FKA2-EU with spring return actuator
Fire damper Type FKA2-EU 17

Spring return actuator GGA...
Construction 326.1E 126.1E
Supply voltage 230 V AC, 50/60 Hz 24 V AC, 50/60 Hz /
24 – 48 V DC
Functional range 198 – 264 V AC 19.2 – 28.8 V AC
19.2 – 57.6 V DC
Power rating Spring winding mechanism 8 VA / 6 W 7 VA / 5 W
Hold position 4 W 3 W
Running time Actuator / spring return 90 s / 15 s
Limit switch Type of contact 2 changeover contacts
Switching voltage 24 – 230 V AC / 12 – 30 V DC
Switching current AC: 6 A (inductive 2 A) / DC: 2 A
IEC protection class / IP protection II / IP 42 or IP 54* III / IP 42 or IP 54*
Storage temperature / ambient temperature -20 to 50 °C / -20 to 50 °C
Ambient humidity < 95% rh, no condensation
Connecting cable Actuator / limit switch 0.9 m, 6 × 0.75 mm² (free of halogens)
GGA actuator optional, weight of FKA2-EU with fusible link + approx. 2.5 kg
*Connecting cable at the bottom
FKA2-EU with Joventa spring return actuator
The FKA2-EU can also be supplied with Joventa spring
return actuator on request:
SFR 2.90 T
SFR 1.90 T
SFR 1.90 T SLC
Technical data
FKA2-EU with spring return actuator
Fire damper Type FKA2-EU18

2.4 FKA2-EU with spring return actuator and duct smoke detector
Dimensions and weight
Fig. 7: FKA2-EU with Belimo spring return actuator and duct smoke detector
B Width of the fire damper (side B)
H Height of the fire damper (side H)
L Length of the fire damper (casing length)
[A] Horizontally arranged spring return actuator
[B] Vertically arranged spring return actuator
Y Keep clear to provide access for operation
Installation side
Operating side
Weight of FKA2-EU with fusible link + approx. 2.5 kg (BFL... and BFN...), see table Ä 10 .
Technical data for spring return actuator, see table
Ä 13 and Ä 15
Sizes 1 to 3 and arrangement of the spring return actuator [A] or [B], see table Ä 10 .
The type RM-O-3-D duct smoke detector must be installed in the lower inspection access and arranged at the
top when assembling the fire damper. For technical details on the duct smoke detector, see the operating and
installation manual for the type RM-O-3-D duct smoke detector.
Technical data
FKA2-EU with spring return actuator and duct smoke detector
Fire damper Type FKA2-EU 19

2.5 FKA2-EU with fusible link and cover grille used as an air transfer unit
Dimensions and weight
Fig. 8: FKA2-EU with fusible link and cover grille used as an air transfer unit
B Width of the fire damper (side B)
H Height of the fire damper (side H)
L Length of the fire damper (casing length)
Y Keep clear to provide access for operation
x 75 mm size 1
87 mm size 2 and 3
Installation side
Operating side
Sizes 1 to 3, see table Ä 10 .
Note: Approvals under building regulations may be required for the use of air transfer units. This must be checked
and applied for by others.
Technical data
FKA2-EU with fusible link and cover grille used as an air transfer unit
Fire damper Type FKA2-EU20