User's Manual

1678 RFD OPERATION MANUAL 26
2.13. VENT OPERATION
2.13.1. In Figure 2-15, the unit vents shown are manually operated and relieve
internal pressure due to heat and altitude. When the vent is closed, it will not leak in
100 feet of water (30 meters) or up to 30,000 feet (9,100 meters) in altitude.
2.13.2. The vent is opened when charging to release any gasses or pressures
accumulated during charging. The vent is closed during normal use or when the unit is
exposed to moisture.
2.13.3. The vent is momentarily opened before use to equalize the case pressure.
2.13.4. To open vent, loosen the knob approximately one turn in the counter-
clockwise direction. To close the vent, turn fully clockwise.
CAUTION Unequal air pressure inside the Controller may affect the operation of
membrane switch keypad. Extreme pressure differentials may irreversibly damage the
keypad and/or cases.
CAUTION Vents in all units should be momentarily opened and closed immediately
before use.
CAUTION Do not open a vent if there is water on or near the vent. Keep the vents
closed when the relative humidity is above 90%. Take necessary precautions to ensure
moisture does not enter the unit case.
Figure 2-15 Vent Operation