Optical Scientific Inc
OFS 2000CW User’s Guide
P/N 1910-905
Rev. 03/28/13
27
5. Slowly turn Enclosure Pressure Control Regulator CW until a “Safe” 0.5” w.c. reading is shown on
the Enclosure Pressure Gauge. Note: If unable to achieve a “ Safe” enclosure pressure, carefully
check all enclosure connections and doors for leakage. Seal as needed.
6. Class I, confirm and document Protective Gas flow shown on temporarily installed flowmeter. Use
formulas below to determine purge time required, 5 minutes minimum.
(Total Enclosure Volume x 4)/Flow rate
(Total Enclosure Volume x 5)/Flow rate
7. Mark purge time on Unit start up instruction name tag using a permanent marker.
8. Set up is complete. Remove any test equipment and proceed with operations.
3.6.3 Pressurization Unit Operation
1. Ensure Protected Enclosure Power is OFF, Enclosure Pressure Control Regulator is closed,
Protective Gas Supply is ON and alarm system is activated (if utilized).
2. If utilized, test Purge Vent for proper operation. [See Section 3.6.2
“Pressurization Unit Setup”]
3. Class II Only - Remove all Dust from protected enclosure.
4. Close and Seal Protected Enclosure.
5. Slowly turn Enclosure Pressure Control Regulator CW until a “Safe” 0.5” W.C. reading is shown on
the Enclosure Pressure Gauge.
6. Class I Only - Allow unit to purge protected enclosure for the required time marked on Unit Start Up
Instructions. 5 minutes minimum. [See
Section 3.6.2 “Pressurization Unit Setup”]
7. Confirm protected enclosure “Safe” pressure is stable. Energize protected enclosure equipment.
8. Loss of “safe” pressure requires immediate attention. Protected enclosure power should be de-
energized if “Safe” pressure cannot be restored within a reasonable amount of time.
