National Vacuum Equipment 887 Challenger Series, Owner'S Manual, Page: 17 / 32

887 Challenger Series | 17 www.natvac.com | 800.253.5500
• Run pump to desired ballast opening vacuum level
(recommend 15” – 18” Hg).
• If ballast is not open (and should be), turn adjustment screw
CCW slowly with flat-head screwdriver until air just begins
to flow.
• If ballast opens before desired vacuum has been reached,
turn adjustment screw CW slowly with flat-head screwdriver
until air is just flowing.
• Place thumb over adjustment hole and ensure opening
level is accurate.
*Without the boss plug, vacuum chamber is not sealed, thus opening level
may vary slightly.
• If adjustment holds accurate, replace locking jam nut, boss
plug, and the ballast air filter.
Adjusting Ballast Valve Cracking Level ________________________________________________
•
The following tools will be required to adjust the ballast valve cracking level
- 7/32” hex drive
- 1/4" hex drive
- Flat head screwdriver
•
Using the 7/32” hex drive, remove the boss plug from the cover of the ballast valve
•
Using the 1/4” hex drive, remove the
locking jam nut
•
The ballast valve cracking adjustment
screw lies under the locking jam nut
•
Remove the ballast air filter from the
top of the ballast valve
•
Run pump to desired ballast cracking
(opening) vacuum (rec. 15” – 18” Hg)
•
If ballast is not open (and should be),
turn adjustment screw CCW slowly
with flat-head screwdriver until air just
begins to flow
•
If ballast opens before desired
vacuum has been reached, turn
adjustment screw CW slowly with flat-head screwdriver until air is just flowing
•
Place thumb over adjustment hole and ensure cracking level is accurate
*Without the boss plug, vacuum chamber is not sealed, thus cracking level may
vary slightly
•
If adjustment holds accurate, replace locking jam nut, boss plug, and the ballast air filter
CAUTION: WHILE THE BALLAST AIR FILTER IS REMOVED, ENSURE NOTHING CAN BE
PULLED INTO THE PUMP. PUMP DAMAGE CAN RESULT
LOCKING JAM NUT
BALLAST AIR FILTER
BOSS PLUG
CHECK AIRFLOW HERE
(BY FEEL AND/OR NOISE)
ADJUSTMENT SCREW
INSIDE STEM
THESE VALUES ARE
APPROXIMATE AND
WILL VARY WITH
MANY FACTORS
RECOMMENDED
OPENING RANGE =
15” Hg TO 18” Hg
Adjusting Ballast Valve Cracking Level ________________________________________________
•
The following tools will be required to adjust the ballast valve cracking level
- 7/32” hex drive
- 1/4" hex drive
- Flat head screwdriver
•
Using the 7/32” hex drive, remove the boss plug from the cover of the ballast valve
•
Using the 1/4” hex drive, remove the
locking jam nut
•
The ballast valve cracking adjustment
screw lies under the locking jam nut
•
Remove the ballast air filter from the
top of the ballast valve
•
Run pump to desired ballast cracking
(opening) vacuum (rec. 15” – 18” Hg)
•
If ballast is not open (and should be),
turn adjustment screw CCW slowly
with flat-head screwdriver until air just
begins to flow
•
If ballast opens before desired
vacuum has been reached, turn
adjustment screw CW slowly with flat-head screwdriver until air is just flowing
•
Place thumb over adjustment hole and ensure cracking level is accurate
*Without the boss plug, vacuum chamber is not sealed, thus cracking level may
vary slightly
•
If adjustment holds accurate, replace locking jam nut, boss plug, and the ballast air filter
CAUTION: WHILE THE BALLAST AIR FILTER IS REMOVED, ENSURE NOTHING CAN BE
PULLED INTO THE PUMP. PUMP DAMAGE CAN RESULT
LOCKING JAM NUT
BALLAST AIR FILTER
BOSS PLUG
CHECK AIRFLOW HERE
(BY FEEL AND/OR NOISE)
ADJUSTMENT SCREW
INSIDE STEM
THESE VALUES ARE
APPROXIMATE AND
WILL VARY WITH
MANY FACTORS
RECOMMENDED
OPENING RANGE =
15” Hg TO 18” Hg