Bosch LTC 7935, Инструкция по эксплуатации

Страница: 10 / 16

EN
| 10
Bosch Security Systems | 24 August 2004
LTC 7935, LTC 7939, LTC 7945, & LTC 7949 Series | Instruction Manual | Pressurizing
7 PRESSURIZING
CAUTION: This unit must be properly
pressurized after it has been opened for
camera servicing. Carefully follow the
pressurizing procedure.
7.1 Supplies
• Dry Nitrogen Supply with Regulator and
Gauge
• Novagard G661 Silicone Compound
03-G661-01G
• Two (2) O-rings 315 1557 903
• Desiccant Bag 315 1597 001
7.2 Pressurize Housing
1. Inspect the O-rings at each end of the housing
for nicks, and debris.
2. If replacing the O-rings, clean the two O-ring
grooves.
3. Apply silicon grease to the O-rings. Use only
the silicon grease specified.
4 Install the O-rings if they were replaced.
5. Install a fresh desiccant bag in the camera
cradle.
CAUTION: Make sure that the retaining
screw is in its fully retracted position.
6. With the retaining screw in its fully retracted
position, insert the camera cradle back into the
housing, following the procedure in Section 6.
Screw the retaining screw into its locked
position.
7. Remove fill valve cap and attach the dry
nitrogen line to the fill valve.
Figure 6: Pressure Fittings
8. Set the regulator to a maximum pressure of
140kPa (20PSIG).
WARNING: The pressure in the housing
must never exceed 140kPa (20PSIG).
9. Purge the housing with dry nitrogen.
The relief valve will open at between 100kPa
(15PSIG) and 140kPa (20PSIG). Continue
purging until all three areas of the humidity
indicator turn blue. This may take 10 to 15
minutes.
Figure 7: Humidity Indicator
10. Remove the nitrogen line from the fill valve
and reduce the housing pressure to
70kPa (10PSIG) by pressing the relief valves.
shown in FIGURE 6.
11. Inspect for leaks around the end seals, fill
valve, relief valve, and the jam nut connector,
as shown in FIGURE 6. If any leaks are found,
reseal and repeat the purge and check again.
12. Let the pressurized unit stand for 24 hours.
13. Recheck the pressure by placing a gauge on
the fill valve. Pressure must be at least 62kPa
(9PSIG). If the pressure is below 62kPa
(9PSIG), check for a leak in the system. The
housing may then have to be depressurized
and opened, in accordance with Section 5.
14. If the pressure has not fallen below
62kPa (9PSIG), bleed the pressure down slowly
via the relief valve, until it is between 35kPa
and 38kPa (5PSIG and 5.5PSIG).
15 Replace the fill valve cap.
Relief Valve
Fill Valve Cap
and Fill Valve
Humidity
Indicator
Jam Nut
Check Seals
for Leaks on
Both Ends
Retaining Screw