Mastercool 90067 7.5 CFM VACUUM PUMP (TWO STAGE) - Manual (Page 2)

2 www.mastercool.com
c. If the level is low, open the intake port and run pump for 15 seconds, stop pump and
observe oil level again. Add a small amount of oil as needed.
3. GAS BALLAST VALVE
The gas ballast valve must be 1/4 turn to fully opened for the first part of the evacuation
procedure. After about two minutes close the valve and continue the evacuation procedure to
reach ultimate vacuum.
FAILURE TO OPEN THE GAS BALLAST VALVE MAY RESULT IN
DAMAGE TO YOUR CARTRIDGE. Failure to close the valve during evacuation will result in poor
vacuum performance.
During the first stages of evacuation, vapors are highly concentrated. Unfortunately, some
vapors will condense into a liquid and mix with the oil, thus reducing the oil’s ability to produce
a deep vacuum. The
GAS BALLAST VALVE emits a controlled amount of dry air into the
pump during compression to minimize this effect and keep oil relatively clean during the first
part of the evacuation. Periodically remove the Gas Ballast Valve Needle and clean or replace
the O-ring. Clean mating surfaces and lightly coat with vacuum pump oil before securely
retightening.
4. CHANGING OIL
In order to reach the deep vacuum required, your vacuum pump needs clean, moisture-free
oil during evacuation. Dirty oil becomes a mixture of corrosive acids and water that effects
the pump’s ability to pull a deep vacuum. Left sitting in the pump, this sludge will rust and
erode internal surfaces...shortening the pump’s life.
Care should be taken to avoid contact of oil with skin or eyes. OIL MAY BE HOT! Used oil
should be properly disposed of in a leakproof corrosive-resistant container according to
local regulations.
a. After every evacuation, while the pump is warm and oil is thin, take a small sample of oil
from the drain port.
b. If the oil is contaminated, drain the oil by placing the pump on a level surface and opening
the oil drain valve. Catch the waste oil in a container and properly dispose of it.
c. If the pump has been sitting for more than one month, the oil is considered contaminated
regardless of appearance and should be changed as outlined above.
d. To add oil, close drain, remove the oil fill cap and fill to the Oil Level Line with fresh oil.
5. INTAKE CONNECTIONS
Replace all caps and finger-tighten. Do not use caps with damaged or missing O-rings and
always store vacuum pump with capped ports to prevent dirt and moisture contamination.
6. PUMP MOTOR
The PUMP and OIL must be above 30˚F. The line voltage must be equal to the rating on the
motor nameplate + / - 10%. Normal operating temperature is approximately 160˚F, which is
HOT to the touch! Line voltage and ambient temperature will affect the normal operating
temperature somewhat. Your vacuum pump is designed for continuous duty and will run for
extended periods without overheating. The motor has an automatic resetting overload
protection feature. If the motor will not restart the pump after shut-off, it may have opened the
thermal protection. Disconnect the pump from the system, wait about 15 minutes for the
motor to cool down and then try again.
RETURNING A PUMP
Please fax a request for a return authorization number to 973-252-2455. This applies to both
warranty and non-warranty service!