Howden Roots Tri-RAM 409, Installation, Operation & Maintenance Manual

7

GEA19684  ISRB_2008 rev._11.15

Lubrication

Due to sludge build-up and seal leakage problems, 
Roots recommendation is DO NOT USE Mobil SHC 
synthetic oils in Roots blowers.

LUBRICATION: For Units with Splash Lubrication on 
Both Ends.

• 

The specified and recommended oil is Roots Synthetic 
oil of correct viscosity per Table 2, page 13.

• 

The proper oil level should be half way or middle of the 
sight gauge when the blower is not operating. DO NOT 
OVERFILL OIL SUMP/S as damage to the blower may 
occur.

• 

Oil level may rise or fall in the gauge during operation to 
an extent depending somewhat on oil temperature and 
blower speed.

• 

It is recommended that the oil be changed after initial 
100 hours of operation.

• 

Proper service intervals of the oil thereafter are based 
on the discharge air temperature of the blower. Please 
refer to the information below to properly determine the 
oil service intervals.

• 

If you choose to use another oil other than the specified 
and recommended Roots Synthetic, use a good grade 
of industrial type non-detergent, rust inhibiting, anti-
foaming oil and of correct viscosity per Table 2, page 
13.

• 

Roots does NOT recommend the use of automotive 
type lubricants, as they are not formulated with the 
properties mentioned above.

Normal life expectancy of the specified and recommended 
Roots Synthetic oil is approximately 6000 hours with an oil 
temperature of 180°F (82°C) or less. As the oil temperature 
increases by increments of 15°F (8°C), the oil life is reduced 
by half for each 15°F (8°C) increase. Example: Oil tem-
peratures of 195°F (90.5°C) will produce a life expectancy 
reduced by half or 3000 hours oil service life.

Normal life expectancy of petroleum based oils is about 
2000 hours with an oil temperature of about 180°F (82°C). 
As the oil temperature increases by increments of 15°F 
(8°C), the life is reduced by half for each 15°F (8°C) increase. 
Example: Oil temperatures of 195°F (90.5°C) will produce life 
expectancy reduced by half or 1000 hours oil service life.

NOTE:

 To estimate oil temperature, multiply the discharge 

temperature of the blower by 0.88. Example: if the discharge 
air temperature of the blower is 200° F, it is estimated that 
the oil temperature is 176° F. 

High ambient temperatures contribute to increased lubrication 
sump temperatures. In situations such as blowers in a enclo-
sure, blowers exposed to radiant heat from other sources, 
blowers installed in areas with poor air circulation or ambient 
temperatures above 80°F the lubrication sump temperature 
should be measured rather than fully rely on the calculation.

Bearings and oil seals are lubricated by the action of the 
timing gears or oil slingers which dip into the main oil sumps 
causing oil to splash directly on gears and into bearings 
and seals. A drain port is provided below each bearing to 
prevent an excessive amount of oil in the bearings. Seals 
located inboard of the bearings in each headplate effectively 
retain oilwithin the sumps. Any small leakage that may occur 
should the seals wear passes into a cavity in each vented 
headplate and is drained downward. Oil sumps on each end 
of the blower are filled by removing top vent plugs, Item (21), 
and filling until oil reaches the middle of the oil level sight 
gauge, Item (37). 

Initial filling of the sumps should be accomplished with the 
blower not operating, in order to obtain the correct oil level. 
Approximate oil quantities required for blowers of the various 
models and configurations are listed in Table 3, page 13.

The oil level should not fall below the middle of the site 
gauge when the blower is idle.

Proper lubrication is usually the most important single 
consideration in obtaining maximum service life and satisfac-
tory operation from the unit. Unless operating conditions are 
severe, a weekly check of oil level and necessary addition of 
lubricant should be sufficient. During the first week of opera-
tion, check the oil levels in the oil sumps about once a day, 
and watch for leaks. Replenish as necessary. Thereafter, an 
occasional check should be sufficient.

More frequent oil service may be necessary if the blower is 
operated in a very dusty location.

*Roots Synthetic oil is superior in performance to petroleum 
based products. It has high oxidation stability, excellent cor-
rosion protection, extremely high film strength and low coef-
ficient of friction. Typical oil change intervals are increased 
2-3 times over petroleum based lubricants. Also, Roots 
Synthetic oil is 100% compatible with petroleum based oils. 
Simply drain the oil in the blower and refill the reservoirs with 
Roots Synthetic oil to maintain optimum performance of 
your Roots blower.

GEA19684_ISRB-2008_Tri-RAM_rev02.16.indd   7

15/02/2016   11:17:05