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Filling and Refilling
1
. Attach the barb to the regulator.
2
. Remove the cap from the Schraeder valve.
3
. Set the gauge on the regulator to between 5 and 8 psi.
4
. Place the air chuck on the Schraeder valve, just as you would
on a tire, and press down to begin filling. Continue until the
regulator stops feeding nitrogen into the housing and begins to
let off excess pressure. In addition, as dry nitrogen is inserted
into the housing the humidity strip will change from pink to blue.
CAUTION:
Do not attempt to fill beyond this point.
NOTE:
The humidity sensitive tape will appear blue under normal
dry conditions. The tape will turn pink if exposed to
moisture or humidity
5
. Replace the metal cap on the Schraeder valve. The cap must be
installed on the Schraeder valve (air input valve) to ensure an
airtight enclosure.
6
. Check the pressure in the unit with a pressure gauge. It should
be 5psi.
7
. Reattach wall mount access cover plate.
PROCEDURES FOR PRESSURIZED HOUSINGS
Pressurized housings provide maximum protection for CCTV
cameras and lenses. The charge of dry nitrogen inside the housing
eliminates the effects of moisture, dust, insects and corrosive exhaust
fumes. This allows a longer lifetime for your surveillance equipment.
To fill (or refill) a pressurized housing, you must have the following:
1. A tank of dry nitrogen (or oxygen)
2. A regulator on the tank
3. A hose with air chuck to connect the regulator to
the housing’s intake valve
Dry Nitrogen
Nitrogen is a readily available. To obtain supplies, check your local
yellow pages for a medical or industrial gas provider. If the tank
is to be carried from location to location, a size of 40 cubic foot is
recommended. This should be enough to refill 30 individual hous-
ings. Handle the tanks with care. Although nitrogen is an inert gas,
the tank is highly pressurized and if the valve or regulator is damaged
the tank could be dangerous. Tanks of dry nitrogen can be kept for
several years.
The Regulator
The tank will have a standard 580 fitting, but a regulator will be
required. A recommended regulator for the tank would be a Harris
#9296-15-580 or #425-15-580. For local distribution you can contact
Harris at 800-241-0804.
The Hose
The purge valve, called a “Schraeder” or “dill” valve, is similar to the
air intake valve on car or bicycle tires. To connect the regulator to
the purge valve on the housing, you’ll need a hose with a 1/4” barb
on one end and an air chuck on the other. The barb connects to the
regualtor, the air chuck to the Scraeder valve. These hoses can be
obtained at local auto parts stores.
PRECAUTIONS:
1
. Always use safety goggles when servicing the unit.
2
. Inspect the enclosure upon opening the product and be sure the
unit has not been damaged during shipping. Domes that have
been cracked or show any signs of damage should be replaced
immediately.
3
. Pressurize the unit with air or dry nitrogen only.
4
. Do not fill the housing to more than 5 psi maximum pressure.
Exceeding 5 psi will damage the enclosure.
5
. Never use an unregulated air supply to pressurize the enclosure.
The valve should be regulated to allow a maximum air pressure of
10 psi.
6
. Be sure you periodically examine the unit and the attached
supporting structure. If the dome shows any signs of wear, such
as stress cracking, it should be replaced immediately.
NOTE: If you have removed the dome it must be reattached and
oriented properly. See page 4 for complete instructions.
