OWNERS MANUAL
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VRV
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1 Warnings................................................................................................................ 2
2 Introduction........................................................................................................... 3
2.1 COSPAS-SARSAT satellite system...............................................................................3
2.2 Global Positioning System (GPS) ..................................................................................4
3 Purpose..................................................................................................................5
4 Description............................................................................................................ 6
4.1 Wall bracket ...................................................................................................................6
4.2 Float-free enclosure.......................................................................................................7
4.3 Manual G4 in enclosure.................................................................................................8
5 Controls................................................................................................................. 9
5.1 ON button......................................................................................................................9
5.2 READY button................................................................................................................9
5.3 Sea switch.....................................................................................................................9
5.4 Lamps..........................................................................................................................10
6 Operating procedure .......................................................................................... 11
6.1 Sinking.........................................................................................................................11
6.2 Abandon ship...............................................................................................................11
6.3 Releasing G4 from a wall bracket.................................................................................11
6.4 Releasing G4 from an enclosure..................................................................................12
6.5 Manual activation.........................................................................................................12
6.6 Deactivation.................................................................................................................13
6.7 Battery condition..........................................................................................................13
6.8 Re-fitting G4.................................................................................................................13
7 False alarms........................................................................................................ 15
7.1 Stand down rescue services ........................................................................................15
7.2 De-activate the EPIRB.................................................................................................15
7.3 Dealing with a transmitting G4.....................................................................................16
8 Wall bracket installation..................................................................................... 17
8.1 Siting............................................................................................................................17
8.2 Mounting procedure.....................................................................................................17
8.3 Mounting instruction plate............................................................................................18
9 Enclosure installation......................................................................................... 19
9.1 Siting............................................................................................................................19
9.2 Mounting procedure.....................................................................................................19
9.3 Mounting instruction plate............................................................................................20
9.4 Marking HRU expiry .....................................................................................................20
9.5 Marking vessel name...................................................................................................21
10 Registration......................................................................................................... 22
10.1 Overview..................................................................................................................22
10.2 How to register.........................................................................................................22
10.3 Warranty form..........................................................................................................22
10.4 Radio licence...........................................................................................................23
10.5 Sale or transfer ........................................................................................................23
11 Maintenance........................................................................................................ 24
11.1 Monthly self-test & inspection...................................................................................24
11.2 HRU replacem ent.....................................................................................................25
11.3 Battery replacement.................................................................................................26
11.4 Servicing..................................................................................................................26
11.5 Transportation..........................................................................................................26
11.6 GMDSS inspections.................................................................................................26
12 Fully disabling a G4............................................................................................27
13 Technical specification ...................................................................................... 28
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1 WARNINGS
This EPIRB is an emergency device for use only in grave
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and imminent danger.
False alarms cost lives and money. Help to prevent them;
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understand how to activate and disable your equipment.
Read the complete manual before installing, testing or
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using the EPIRB.
Ensure the EPIRB is registered with your local authorities
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(Flag State nation).
The EPIRB contains no user servicable parts. Return to
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your dealer for battery replacement or other service. Do
not open.
Dispose of this device safely. Contents include Lithium
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batteries; do not incinerate, puncture, deform or shortcircuit.
This device emits radio frequency radiation when
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activated. Because of the levels and duty cycles, such
radiation is not classed as harmful.
Do not stare at strobe.
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2 INTRODUCTION
2.1 COSPAS-SARSAT satellite system
The COSPAS-SARSAT system provides distress alert and location information to
search and rescue authorities anywhere in the world for maritime, aviation and
terrestrial users in distress.
There are two satellite arrays carrying the COSPAS-SARSAT system. The principal
array is LEOSAR (Low Earth Orbit Search and Rescue) which has seven satellites in
polar and near-polar orbits. The orbits of these satellites are arranged to scan the
entire surface of the Earth; on average, a satellite comes into view every 45 minutes.
LEOSAR satellite path and scan footprint
Distress transmissions from EPIRBs are picked up by the satellites and retransmitted
to ground receiving stations, which then pass the message to the appropriate rescue
organisation. On average, the total delay from activation of an EPIRB to the message
being received by the rescue services is 90 minutes.
COSPAS-SARSAT is in an advanced stage of commissioning the second satellite
array, GEOSAR (Geostationary Search and Rescue). This array uses geostationary
satellites which are always in view (over their area of coverage), so that reception of
the EPIRB signal is instantaneous.
GEOSAR coverage
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2.2 Global Positioning System (GPS)
(
The GPS system is a satellite array which enables a receiver located anywhere on
Earth to determine its exact position, usually to within 100m.
The array uses 24 satellites (plus spares) orbiting the Earth in six orbital planes, four
satellites per plane, as shown below. These are arranged so that at least five satellites
are within range of any receiver (which can be anywhere) at all times.
GPS satellite orbital planes
Each satellite transmits information which enables its position and distance from the
receiver to be calculated. By combining these data for multiple satellites, the exact
position of the receiver can be determined.
Operation of GPS receiver
size exaggerated for clarity)
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3 PURPOSE
An Emergency Position Indicating Radio Beacon (EPIRB) is used to alert search and
rescue services in the event of an emergency. It does this by transmitting a coded
message on the 406MHz distress frequency. This message is relayed via satellite and
earth station to the nearest rescue co-ordination centre.
The satellite system is run by COSPAS-SARSAT, and has already been described.
With the geostationary satellite section being commissioned, the alerting delay is
reduced from typically 90 minutes to a few minutes within the geostationary satellite
coverage.
Instant alerting is good news, but they still need to know where you are. The
advantage of the G4 EPIRB is that it has a built in GPS receiver, so within minutes of
activation it will have determined your latitude / longitude coordinates and will have
transmitted these to the rescue centre. The position fix is accurate to 150m*.
To operate properly the G4 needs a clear view of the whole sky. If its view is blocked
and it is unable to get a position fix, then the system defaults to using a polar orbiting
satellite to determine position. In this case, there is typically a 45 minute delay before
the position is known and the accuracy is limited to within 5km (3 miles). This is the
original system that standard (non-GPS) EPIRBs use. To get the full advantage of the
G4 it is important to give it a clear view of the whole sky.
The G4 transmits a message that identifies the exact vessel to which it was registered.
Knowing which vessel is in distress allows the rescue services to eliminate false
alarms and launch an appropriate rescue.
The G4 also has a secondary distress transmitter. This transmits on 121.5MHz and is
used for “homing” purposes. When the rescue services get close, this allows them to
direction find on the signal. To cater for searches at night, the G4 has a bright flashing
light that aids final visual location.
Battery expiry date
Antenna
READY
button
Lanyard
* If the programmed identity
is a Radio Call Sign (RCS)
then accuracy is limited to 5km
Strobe
Green lamp
PRESS TO
TEST
READY
Program point
Red lamp
S
E
A
L
ON button
under here
Sea contacts
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4 DESCRIPTION
The G4 is a powerful self-contained distress transmitter. It is powered by a light weight
Lithium battery that has a replacement interval of 5 years. An EPIRB is intended to be
a one-shot device; once activated it can operate for at least 48 hours. It operates best
while floating in water, but it can also be operated while on board or in a liferaft.
Refering to the previous figure, the key components of your G4 are as follows:
Antenna This is a flexible whip. It must be near vertical when
operating.
If the antenna gets bent, gently straighten it out.
Strobe light This is the glass U-tube visible through the clear lens dome.
When the G4 is activated this will flash every few seconds.
Red lamp Visible through the clear lens dome at the rear of the G4.
This stays on or flashes to show you which mode you are
in.
Green lamp This flashes when the GPS gets a position fix.
Program point A dimple in the clear dome, through which your supplier can
optically input the coded message unique to your G4.
must
You
authorities.
READY button Press this key once to de-activate the G4. Hold it down to
run the built-in self-test, which checks basic operation.
ON button Press this key to activate the G4 manually. The key is
protected by a sliding door which is fitted with a tamper
seal.
Sea switch The two screw heads below the keys are sea switch
contacts. Submerge these in water to automatically activate
the G4.
Lanyard Pull the lanyard spool down to free it. Use the cord to tether
the G4 to a survival craft.
Never
register the coded message with local
tie the G4 to your vessel.
4.1 Wall bracket
If you purchased the manually activated version (G4m), this is normally supplied with a
wall mounting bracket (see section 8). The bracket is made from white plastic so it will
not rust. Its top section is sprung loaded, so that one simple squeeze will quickly
release the G4 allowing it to be carried to a liferaft. The wall bracket should be sited in
plain view near an emergency exit. This bracket is more than just a stowage point, it
contains a magnet which disarms the G4’s sea switch. If you do not stow the G4 in its
bracket, there is a risk of the G4 activating if it gets wet.
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4.2 Float-free enclosure
If you purchased the automatically activated version (G4a), also known as the “floatfree” version, then your G4 is supplied in a plastic enclosure (see section 9). This is
much more than just a protective housing, it contains a sprung loaded lever which
automatically pushes the enclosure lid off and releases the G4 if your vessel sinks.
This automatic ejection is controlled by a device called a Hydrostatic Release Unit
(HRU). If the enclosure is submerged then before it reaches 4 metres (13 feet) deep
the HRU cuts a plastic rod that holds back the spring and the lid is ejected, releasing
the EPIRB which floats to the surface and switches on automatically.
The diagram below illustrates the automatic release sequence:
1. As the vessel sinks, the enclosure fills with water. The HRU contains a
blade which is released due to water pressure acting on a diaphragm.
Before it reaches a depth of 4 metres, the HRU will operate and cut the
plastic rod, releasing the coil spring.
2. The spring pushes the G4 and the enclosure lid outwards. As the lid
pivots off it disengages from the screw head that helped hold it in place.
The lid is weighted so it rolls over and falls away.
3. As the G4 floats away from the lid, it moves out of range of the magnet.
Once away from the magnet its sea switch becomes armed.
4. The sea switch activates. The EPIRB then floats on the surface with its
strobe light flashing. After 3 minutes it makes its first distress
transmission.
H
R
U
Magnet
1) HRU cuts rod
2) Lid ejects
3) EPIRB arms once
away from magnet
4) sea switch
activates
If you need to activate your G4 manually, it can be freed from the enclosure after
pulling out the R-shaped retaining pin and removing the lid.
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4.3 Manual G4 in enclosure
Customers who need to mount their G4 in an exposed position can select the
protective enclosure without an HRU fitted (G4c). This means that the G4 will
free if your vessel sinks. This is known as a category 2 EPIRB. You can tell which
enclosure you have by reading the category from the front of the enclosure:
G4a
G4c
Category 1 HRU fitted Automatic float-free
Category 2 No HRU fitted Will not float free
not
float
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