OBSTRUCTION
LIGHTING
GUIDELINES
oBSTRUCTION lIGHTING GUIDELINES
INTRODUCTION TO OBSTRUCTION LIGHTING GUIDELINES
Any structure that exceeds 200’ above ground level generally needs to be
marked (lighted) according to FAA/ICAO Regulations. There are many
factors that can affect obstruction marking requirements, such as weather,
terrain, proximity to airports, etc. The information presented in the
following pages of this catalog is intended to provide basic guidance for
structure marking.
The FAA and ICAO guidelines presented herein describe minimum
requirements for various structure heights and descriptions of equipment to
be used. Note that for Red Lighting Systems, the tower must be painted in
alternating levels of aviation orange and white to provide maximum daytime
visibility (red lights are for nighttime only). In the case of white or dual
lighting systems, the need for painting the tower is eliminated.
Height is only one important consideration when choosing how a structure is
to be marked. The products presented in this catalog support the obstruction
lighting requirements set forth by the FAA/FCC and ICAO. In addition,
Unimar is a master distributor for each of the following product lines:
Cooper Crouse-Hinds, ABB Controls (Formerly Entrelec, SSAC), Flash
Technology and Dialight Corporation.
For industrial applications, professional assistance will be required, for
example in the case of aviation lighting for industrial facilities or wind farm
lighting applications. Let your sales representative or our Technical Support
staff help you determine which is the best lighting solution for your unique
application.
78
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Guidelines for Hazardous Areas
Guidelines for the use of Electrical Equipment in Potentially Explosive
Atmospheres
Introduction
Potentially explosive atmospheres exist where there is a risk of explosion due to mixtures of gas/
air, vapor/air, dust/air or other flammable combinations. In such areas there is a necessity to
eliminate sources of ignition such as sparks, hot surfaces or static electricity which may ignite
these mixtures. Where electrical equipment has to be used in these areas it must be so designed
and constructed as not to create sources of ignition capable of igniting these mixtures. Before
electrical equipment can be used in a potentially explosive atmosphere, a representative sample
has to be fully tested and certified by an independent authority such as PTB in Europe or UL in
the USA.
This information is intended as a guide only and further expert guidance should be sought before
placing into service, maintaining or repairing any item of equipment in a potentially explosive
atmosphere.
Where comparisons are shown between, for example, European and North American practice
this may be an approximation and individual standards/codes of practice should be consulted for
precise details.
Area Classification
Plants are divided into Zones (European and IEC method) or Divisions (North American method) according to the likelihood of a
potentially explosive atmosphere being present.
Note: North American legislation now allows Zones to be used to classify areas, where this practice is used it follows the NEC and CEC.
European & IEC Classification
Definition of Zone or Division
North American Classification
Zone 0 (gases)
Zone 20 (dusts)
An area in which an explosive mixture is continuously present or
present for long periods
Class I, Division 1 (gases)
Class II, Division 1 (dusts)
Zone 1 (gases)
Zone 21 (dusts)
An area in which an explosive mixture is likely to occur in
normal operation
Class I, Division 1 (gases)
Class II, Division 1 (dusts)
Zone 2 (gases)
Zone 22 (dusts)
An area in which an explosive mixture is not likely to occur in
normal operation and if it occurs it will exist only for a short time
Class I, Division 2 (gases)
Class II, Division 2 (dusts)
Class III, Division 1 (fibers)
Class III, Division 2 (fibers)
Gas Groups (plus dust & fibers)
There are two main gas groups, Group
I – Mining only and Group II – Surface
Industries
These categories are used in European and
IEC groupings.
Group I is concerned only with underground
mining where methane and coal dust are
present.
Group II gases occurring in surface industries
are sub-grouped according to their volatility.
This enables electrical equipment to be
designed to less onerous tolerances if it is to be
used with the least volatile gases.
Typical Gas/Material
Methane
European/IEC Gas Group
North American Gas Group
I
--
Acetylene
IIC
A
Hydrogen
IIC
B
Ethylene
IIB
C
Propane
IIA
D
Metal Dust
--
E
Coal Dust
--
F
Grain Dust
--
G
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79
Guidelines for Hazardous Areas
Temperature
Temperature Classification
Hot surfaces can ignite explosive atmospheres. To
guard against this, all electrical equipment intended
for use in a potentially explosive atmosphere is
classified according to the maximum surface
temperature it will reach in service. This temperature
is normally based on a surrounding ambient
temperature of 40˚ Centigrade (104˚ Fahrenheit).
This temperature can then be compared to the
ignition temperature of the gas(es) which may come
into contact with the equipment and a judgment
reached as to the suitability of the equipment to be
used in that area.
Example (see table at right): Butane has an ignition
temperature of 365° Centigrade - equipment used in the
vicinity of this gas would need a T rating of T2 or better.
European/IEC
North American
Maximum Surface Temperature
T1
T1
450˚C
T2
T2
T2A
T2B
T2C
T2D
300˚ C
280˚ C
260˚ C
230˚ C
215˚ C
T3
T3
T3A
T3B
T3C
200˚ C
180˚ C
165˚ C
160˚ C
T4
T4
T4A
135˚ C
120˚ C
T5
T5
100˚ C
T6
T6
85˚ C
Types of Electrical Equipment Suitable for use in Potentially Explosive Atmospheres
Different techniques are used to prevent electrical
equipment from igniting explosive atmospheres.
Restrictions for where these different types of
equipment can be used are as follows:
Zones 1 & 2
EExd
EN60079-1
Zones 1 & 2
Exd
IEC60079-1
Class I Divisions 1 & 2
-UL1203
Intrinsic Safety – A technique whereby electrical energy is
limited such that any sparks or heat generated by electrical equipment is sufficiently low as to not ignite an explosive atmosphere.
Zones 0, 1 & 2
EExi
EN50020
Zones 1 & 2
Exi
IEC60079-11
Class I Divisions 1 & 2
-UL913
Increased Safety – This equipment is so designated as to
eliminate sparks and hot surfaces capable of igniting an explosive
atmosphere.
Zones 1 & 2
EExe
EN60079-7
Zones 1 & 2
Exi
IEC60079-7
----
Purged and Pressurized – electrical equipment is housed in
an enclosure which is initially purged to remove any explosive
mixture, then pressurized to prevent ingress of the surrounding
atmosphere prior to energization.
Zones 1 & 2
EExp
EN50016
Zones 1 & 2
Exp
IEC60079-2
Class I Divisions 1 & 2
-NFPA496
Encapsulation – A method of exclusion of the explosive atmosphere by fully encapsulating the electrical components in an
approved material.
Zones 1 & 2
EExm
EN60079-18
Zones 1 & 2
Exm
IEC60079-18
---
Oil Immersion – The electrical components are immersed in oil,
thus excluding the explosive atmosphere from any sparks or hot
surfaces.
Zones 1 & 2
EExo
EN50015
Zones 1 & 2
Exo
IEC60079-6
Class I Division 2
–UL698
Powder Filling - Equipment is surrounded with a fine powder,
such as quartz, which does not allow the surrounding atmosphere
to come into contact with any sparks or hot surfaces.
Zones 1 & 2
EExq
EN50017
Zones 1 & 2
Exq
IEC60079-5
----
Non-sparking – Sparking contacts are sealed against ingress of
the surrounding atmosphere, hot surfaces are eliminated.
Zone 2
EExn
EN60079-15
Zone 2
Exn
IEC60079-15
----
Flameproof Enclosure – An enclosure used to house electrical
equipment, which when subjected to an internal explosion will
not ignite a surrounding explosive atmosphere.
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European
IEC
NEC
Area of use
Area of use
Area of use
Designation Standard Designation Standard Designation Standard
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Guidelines for Hazardous Areas
Selection, Installation & Maintenance of Electrical Equipment Intended for use in Potentially Explosive Atmospheres
International and national standard requirements for the safe use of electrical equipment in potentially explosive atmospheres
as follows:
International
Europe
USA
Canada
General Recommendations
IEC60079-14
EN60079-14
NEC Chapter 5
CEC Section 18
Classification of Hazardous Areas
IEC60079-10
EN60079-10
NEC Chapter 5
CEC Section 18
Inspection and Maintenance of Electrical Equipment
IEC60079-17
EN60079-17
Requirements for Flameproof Enclosures
IEC60079-1
EN60079-1
NEC Chapter 5
CEC Section 18
Requirements for Intrinsically Safe Equipment
IEC60079-11
EN60079-11
NEC Chapter 5
CEC Section 18
Requirements for Increased Safety Equipment
IEC60079-7
EN60079-7
NEC Chapter 5
CEC Section 18
Requirements for Purged and Pressurized Equipment
IEC60079-14
EN60079-14
NEC Chapter 5
CEC Section 18
Requirements for Non-Sparking Equipment
IEC60079-15
EN60079-15
--
--
CEC Section 18
CEC Section 18
UNIMAR advises that all explosion-proof electrical equipment is maintained by suitably trained personnel, in accordance with the
manufacturers’ recommendations.
Any spare parts used should be purchased from the original manufacturer and repairs should be carried out by the manufacturer or
under his supervision, in order that the item remains in conformance with the certification documents.
The Certification Process
All electrical equipment, intended for use in a potentially explosive atmosphere, should be certified as suitable for such use.
The methods for obtaining certification differ in detail (see below) between each certifying body or group of bodies (e.g. CENELEC).
Basically this process consists of supplying a representative sample of the equipment along with a set of drawings to a recognized test/
certification body (e.g. PTB) that in turn test the equipment against a recognized standard (e.g. EN60079-1) and issues a certificate.
The user of the equipment can then refer to this certificate to enable him to safely put the item into service in a zone appropriate to the
certification.
European Practice
All equipment, both electrical and mechanical, intended to be put into service within the EU has to be certified in
accordance with the ATEX directive.
It should be noted also that MECHANICAL equipment is covered by the ATEX directive; so for the first time items such as gearboxes
will have to carry ATEX certification.
The equipment coding signifying compliance with ATEX is as follows:
112G i.e.
Explosion-proof in accordance with ATEX.
II Group II surface industries
2 Category 2 equipment (suitable for use in Zone 1) note:
Category 1 is suitable for Zone 0
Category 3 is suitable for Zone 2
G Suitable for atmospheres containing gas (D is suitable for atmospheres containing dust)
Equipment will be CE marked when certified to ATEX
North American Practice
Sample equipment and supporting documentation are submitted to the appropriate authority e.g. U.L., F.M., C.S.A.
The equipment is tested in accordance with relevant standards for explosion protection and also for general electrical requirements e.g.
light fittings.
After successful testing, a listing is issued allowing the manufacturer to place the product on the market.
The product is marked with the certification details such as the gas groups A, B, C, D and the area of use e.g. Class I, Division 1.
NEC  is a registered trademark of the National Fire Protection Association.
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81
Guidelines for Hazardous Areas
Worldwide Certifications
Most countries outside Europe or North America use the IEC standards as a basis for their own national standards.
The Russian Federation certifies equipment to GOST ‘R’ standards, these closely follow CENELEC practice.
In Russia, certain products used in fire alarm systems may be required to carry the Russian fire approval (VNIIPO). Note that not
all Unimar products that have been certified to GOST ‘R’ are VNIIPO approved. Check specification on technical data sheets before
ordering.
Kazakhstan has a certification process (GOST ‘K’) where approval is normally based on compliance with CENELEC standards.
Certification is China is based on compliance with international standards such as CENELEC or UL, or their own CQST standard.
There is a scheme is place which will, when fully adopted, allow for internationally recognized certification to become a reality, this is the
IEC EX SCHEME. This uses the IEC standards and IEC recognized test and certification bodies to issue mutually recognized test reports
and certificates. The scheme is in its infancy and its level of success cannot yet be measured.
Ingress Protection
2 digits are used to denote the level of ingress protection that a piece of apparatus provides:
IP =
Solids
Liquids
0
No protection
0
No protection
1
Protected against solid objects up to 50mm, e.g. hands
1
Protected against vertically falling drops of water
2
Protected against solid objects up to 12mm, e.g. fingers
2
Protected against water spray up to 15˚ from vertical
3
Protected against solid objects up to 2.5mm, e.g. tools
3
Protected against water spray up to 60˚ from vertical
4
Protected against solid objects over 1mm, e.g. wires
4
Protected against water sprays from all directions
5
Protected against dusts -- (No harmful deposits)
5
Protected against water jets from all directions
6
Totally protected against dust
6
Protected against strong water jets from all directions, e.g. offshore
7
Protected against immersion between 15cm and 1m in depth
8
Protected against long immersion under pressure
NEMA Standards
North American practice is to use NEMA
standards to describe ingress protection, i.e.:
NEMA 3
NEMA 4
NEMA 4X NEMA 6
82
is similar to IP 54
is similar to IP 55
is similar to IP 56
is similar to IP 67
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FAA & ICAO Configurations
faa lighting system configuration
Type A
Red Lighting System
Type B
High Intensity White
Type C
High Intensity White
(Medium Intensity White Beacon on appurtenance over 40' tall)
Type D
Medium IntensityWhite
Type E
Dual Lighting System / Red & Medium Intensity White
Type F
Dual Lighting System / Red & High Intensity White
(Dual Beacon on appurtenance over 40' tall)
faa equipment classification
L-810
Steady-Burning Red Obstruction Light
L-856
High Intensity Flashing White Obstruction Light (40 FPM)
L-857
High Intensity Flashing White Obstruction Light (60 FPM)
L-864
Medium Intensity Flashing Red Obstruction Light (20-40 FPM)
L-865
Medium Intensity Flashing White Obstruction Light (40 FPM)
L-864/L-865
Dual Flashing Red Obstruction Light / Medium Intensity Flashing White
Obstruction Light (40 FPM)
L-866
Medium Intensity Flashing White Obstruction Light (60 FPM)
L-885
Red Catenary (60 FPM)
FPM = Flashes Per Minute
icao lighting system configuration
Type A
Low Intensity, Red Steady
Medium Intensity, White Flashing
High Intensity, White Flashing
Type B
Low Intensity, Red Steady
Medium Intensity, Red Flashing
High Intensity, White Flashing
Type C
Low Intensity (Mobile), Yellow/Blue Flashing
Medium Intensity, Red Steady
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83
faa REGULATIONS
FAA WHITE LIGHTING Type C †
White Lights for Night
1751' – 2200'
and Type
D † - White Lights for Day/
**
CONFIGURATION KEY
L-865 Medium Intensity
Flashing Beacon
L-856 High Intensity
Flashing Beacons
1401' – 1750'
**
1051' – 1400'
**
701' – 1050'
**
501' – 700'
**
351' – 500'
*
200' – 350'
C-6
C-5
C-4
C-3
C-2
D-2
D-1
†
This illustration is meant to be used as a guideline only. Please refer to FAA advisory circular 70/7460-1K.
*Including any appurtenance.
**Excluding appurtenance.
84
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*
FAA Regulations
FAA RED LIGHTING Type A†- Painted Tower/RedLights for Night
1751' – 2200'
CONFIGURATION KEY
*
L-864 Flashing Beacon
L-810 Obstruction Light
1401' – 1750'
*
1051' – 1400'
*
701' – 1050'
*
351' – 700'
*
151' – 350'
*
0' – 150'
A-6
A-5
A-4
A-3
A-2
A-1
*
A-0
This illustration is meant to be used as a guideline only. Please refer to FAA advisory circular 70/7460-1K.
*Including any appurtenance.
†
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85
FAA Configurations
FAA Regulations
FAA DUAL LIGHTING Type E †
Lights for Night
1751' – 2200'
and Type
F † - White Lights for Day/Red
CONFIGURATION KEY
**
L-864/L-865 Medium
Intensity Dual Red/White
Flashing Beacon
L-864 Flashing Beacon
L-856 High Intensity
Flashing Beacons
1401' – 1750'
L-810 Obstruction Light
**
1051' – 1400'
**
701' – 1050'
**
501' – 700'
**
351' – 500'
*
200' – 350'
F-6
F-5
F-4
F-3
F-2
E-2
E-1
†
This illustration is meant to be used as a guideline only. Please refer to FAA advisory circular 70/7460-1K.
*Including any appurtenance.
**Excluding appurtenance.
86
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*
FAA Regulations
FAA/FCC CHIMNEY and STACK LIGHTING REQUIREMENTS
NOTE: Information is provided to assist in your product selection
based on AC 70/7460-1K and AC 150/5345-43F Advisory Circular.
Your application may demand special lighting requirements. LED
fixtures are ideal for solid structure applications.
number of lights per level / structure diameter
(20’ or less)
Diameter
(21’ - 100’)
Diameter
(100’ - 200’)
Diameter
D
D
D
4 lights / level
6 lights / level
3 lights / level
NOTE: Number of lights per level is the minimum
number and types of lighting levels / height
NOTE: Lowest level of lights must be raised above the height of adjacent structures. If your structure is not represented,
allow us to assist you with selecting the proper products for your specific structure. Example: For structure "A1",
one L-864 beacon is required at top and L-810 sidelights are to be mounted at ½ tower height.
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8787
ICAO
Regulations
ICAO
Configurations
ICAO RED LIGHTING † - Painted Tower/RedLights for Night
521m – 624m
**
CONFIGURATION KEY
*
Medium Intensity
Type C (steady) L-864
Low Intensit y
Type B (steady) L-810
417m – 520m
Low Intensity doubl e
Type B (steady) L-810
*
313m – 416m
*
NOTE: Spacing between levels
must not exceed 52m. For more
information on specific applications,
call Technical Support.
209m – 312m
*
105m – 208m
*
46m – 104m
*
0m – 45m
†
This illustration is meant to be used as a guideline only. Please refer to ICAO (Annex 14).
**May use low intensity Type B or medium intensity Type B at this level.
*Including any appurtenance.
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ICAO Regulations
ICAO WHITE LIGHTING † - White Lights for Day/White Lights for Night
526m – 630m
CONFIGURATION KEY
**
Medium Intensity
Type A — L-865/L-86 6
High Intensity
Type A — L-856/L-85 7
421m – 525m
**
316m – 420m
**
211m – 315m
**
151m – 210m
**
106m – 150m
*
45m – 105m
*
†
This illustration is meant to be used as a guideline only. Please refer to ICAO (Annex 14).
*Including any appurtenance.
**Excluding any appurtenance.
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ICAO Regulations
ICAO DUAL LIGHTING † - White Lights for Day/Red Lights for Night
521m – 624m
**
CONFIGURATION KEY
Medium Intensity Type A
and Type B—L-864/L-865
Medium Intensity Type B
L-856/L-857 or L-86 4
(Use all Type B or all Type C
)
)
High Intensity Type A
L-856/L-857
417m – 520m
**
Low Intensity Type B—L-81
313m – 416m
**
209m – 312m
**
151m – 208m
**
105m – 150m
*
45m – 104m
†
This illustration is meant to be used as a guideline only. Please refer to ICAO (Annex 14).
*Including any appurtenance.
**Excluding any appurtenance.
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*
0
Lowering System
LOWERING SYSTEM
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91
Application Notes
APPLICATION NOTES
Note 1: safety
As with all products where high voltages may be present, take great care to be sure ALL
electrical power is removed before servicing any components in the system.
Note 2: neutral and grounding requirements
All Unimar Obstruction Lighting Controls require the presence of a neutral electrical
conductor.
NOTE: Throughout this guide "230V" refers to non-domestic locations using 220-240V
line-neutral or line-line with one leg grounded.
The transmission of alternating current (AC) is a sinusoidal wave train. The "zero" point
(neither positive nor negative) is the "neutral". The system may be single phase, 2-wire;
single phase, 3-wire; or 3 phase, 4-wire to have a neutral conductor present. The neutral
(N) is available in most systems by its connection to ground, either at the power source or
by transformer connections to ground.
The solid-state devices used in Obstruction Lighting Controllers require zero voltage
switching for the contacts. The contact closes only when the AC sine wave crosses zero or
very close to zero. This concept also reduces inrush current and RFI and increases lamp
life.
The accompanying diagrams (facing page) show the various ways a neutral can be
provided for 480/240V systems. The techniques are similar for 380/220V systems. Figure
1 and Figure 3 are extensively used in North America. The frequency is 60Hz. In other
countries, installations may be 50Hz or 60Hz. The secondary side of the circuit shown
in Figure 3 is the most commonly used for power input to controllers. With single phase,
3-wire (L-N-L) load balancing can be achieved by dividing the load circuits. Figure 2
illustrates a method for connecting a single phase 1:1 or 2:1 transformer and providing
a neutral. Figure 4 shows another method for obtaining a single phase, 3-wire (L-N-L)
system with a neutral by using two separate single phase transformers with matched
voltage windings. The ends of the primary and secondary windings are tied together
as shown with the resulting center-tapped winding of the secondary side becoming a
neutral. This is referred to as a "floating" neutral. Figure 5 is a common scheme used
outside of North America. In this case it is difficult to find the "zero" point on the wave
train. If one line of a 240V, 2-wire supply is in fact grounded, then it is 240V line to
neutral for use with the 230VAC controller.
Regarding grounding: Contollers incorporate a ground lug for equipment grounding
purposes, particularly when fault current situations occur. While it may be interpreted
that this ground is also the "neutral", avoid any interconnection of the neutral in the
power system and this equipment.
92
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Application Notes
Figure 1
Delta Transformer
X1
Note 3: wire size and voltage drop
X2
FAA Advisory Circular 150/5345-43F states that incandescent lamps must operate to
within 3% of the rated lamp voltage to provide proper light output.
X3
Wye Transformer
L3
F
120V
Line to Line = 280V, 30, 4 Wire
L2
120V
N
Correct lamp voltage is achieved by utilizing a combination of the correct wire size and
the correct supply voltage. Whenever possible, use the recommended wire size shown in
the wiring / schematic diagram provided with your obstruction lighting controller.
120V
L1
Line to Neutral = 120V, 10
L1 to N to L2 = 120V, 10, 3 Wire
GND
Following is the formula for calculating voltage drop to the lamp based on wire size,
length of the wire and the current draw:
Figure 2
1:1 or 2:1 Transformer
X1
Voltage Drop =
L1
480V or 240V
In some applications a boost transformer may be necessary.
240/230V or 120V
X2
2K x L x l x 0.8666
C.M.
NOTE: K = 12 for copper or 18 for aluminum; L = length in feet from the source to the load;
l = load current in amperes; C.M. = circular mil area of the conductor or total circular mil
area for paralleled conductors.
L2
GND
Figure 3
2:1 Transformer
X1
L1
240V
Note 4: lightning protection
120V
480/240V
N
120V
X2
L2
In some areas where lightning is a common occurrence, lightning arrestors and/or
lightning rods should be considered to protect the obstruction lighting equipment.
GND
Note 5: conduit and moisture
Figure 4
2:1 Transformer
X1
L1
120V
N
480V
Care should be taken to prevent a buildup of moisture in conduit runs that could damage
the obstruction lighting equipment. Vent and drain fittings should be installed in the
appropriate positions in the conduit runs. The photo-control should never be installed
in-line with the conduit run to the lights.
120V
Note 6: "Hot" (ungrounded) towers
GND
Figure 5
1:1 or 2:1 Transformer
X1
480V or 240V
When utilizing isolation transformers on Hot Towers, never attempt to flash the primary
of the transformer with a solid-state flasher.
L1
220/230/240V
X2
For assistance on flashing and/or alarms for Hot Towers, contact one of Unimar's
application engineers at 1-800-739-9169 or 1-315-699-4400.
L2
N or GND
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93