Bosch VG4 Series, Руководство по установке

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44 en | Installing the Pendant Arm Wall, Corner, and Mast (Pole) Mounts VG4 Modular Camera Series
F.01U.216.010 | 8.0 | 2011.02 Installation Manual Bosch Security Systems, Inc.
2.11.8 Pressurizing the Housing
Nitrogen is a dry gas that is used to prevent moisture ingress into the housing. There are small
spaces inside the housing that may trap small pockets of oxygen. This process requires you to
purge, or eliminate, these small pockets of oxygen.
The VG4 Pressurized Environmental Housing can maintain a maximum internal pressure of
75.84 kPa (11 psi) ± 5%. Above 75.84 kPa (11 psi), the pressure relief valve cracks and then
seats at a pressure of 65.50– 68.95 kPa (9.5–10 psi).
Follow these steps to pressurize the housing:
1. Set the gauge on the regulator to 86.18 kPa (12.5 psi).
2. Place the air chuck on the Schrader fill valve, just as you would on a tire, and press down
to begin filling the housing. The dome should reach maximum pressure in under ten
seconds.
Excess air should vent from the pressure relief valve after the maximum internal pressure
of 75.84 kPa (11 psi) is reached.
3. Remove the air chuck from the Schrader fill valve.
4. Attach a pressure gauge to the Schrader fill valve. Ensure that the pressure inside the
housing is between 62.05 kPa (9 psi) and 79.98 kPa (11.6 psi).
5. After you verify the pressure, follow these steps:
a. Reconnect the nitrogen air chuck and to the Schrader fill valve and press down to
begin purging the housing.
Excess air immediately vents from the pressure relief valve.
b. Keep the chuck attached the Schrader fill valve and allow the excess nitrogen to
escape from the pressure relief valve for 1 minute to ensure that only nitrogen is
present inside the housing.
c. Remove the nitrogen air chuck from the Schrader fill valve.
d. Attach a pressure gauge to the Schrader fill valve. Ensure that the pressure inside
the housing is between 62.05 kPa (9 psi) and 79.98 kPa (11.6 psi).
2.11.9 Servicing the VG4 Pressurized Environmental Housing
To service the AutoDome Pendant, use the following procedure to remove the Bubble:
1. Purge the nitrogen from inside the Pressurized Environmental Housing and bubble.
2. Loosen, but do not fully remove, the eight (8) captive screws using a T25 pin-in Torx
driver from the bubble support ring.
3. Support the bubble with your hand to ensure that it does not fall as you fully remove the
captive screws using an alternating pattern.
4. Remove the bubble and the bubble support ring.