Maintenance; Blower Assembly - Modine MDB Série Manuel D'installation Et De Maintenance

maintenance

caution
When using a drill bit to clean the burner gas ports, do not
distort or enlarge the ports. Do not use a power drill.
All heating equipment should be serviced before each heating
season to assure proper operation. The following items may be
required to have a more frequent service schedule based on
the environment in which the unit is installed, and how long the
equipment is operated.

Blower assembly

The blower assembly includes the fan bearings, drive sheaves,
and drive belts.
Belt tension should be rechecked shortly after the unit has
been installed to check for belt stretching.
After the initial start-up period, monthly checks are
recommended.
Blower bearings should be checked and lubricated monthly
if the bearings are not of the permanently-lubricated type.
On units provided with spider bearings, the bearings are
permanently lubricated and should not require additional
lubrication. Units provided with pillow block bearings are also
supplied with permanent lubrication; however, see vendor's
literature supplied with unit for lubrication recommendations.
Bearings should be checked for any unusual wear and
replaced if necessary. Also make sure bearings are secure.
Drive sheaves should be checked at the same time the
bearings are inspected. Check to make sure the pulleys are in
alignment and are securely fastened to the blower and motor
drive shafts.
Filters
If the unit is supplied with a dirty filter switch and light, clean or
replace the filters any time the dirty filter light comes on. See
pages 34-37 for quantities and sizes.
Units that do not have the optional dirty filter switch and light
should have the filters checked monthly. Clean or replace if
necessary. In dirty atmospheres, filter maintenance may be
required more often.
Burners
Generally, direct-fired burners tend to be self-cleaning;
however, if the unit is installed in a severely dirty environment,
a periodic cleaning of the burner may be required.
Depending on the size of the burner, it may not be practical to
attempt to remove the burner from the unit for cleaning. Use
the following steps to clean the burner.
1. Turn off all gas and power. Remove the pilot and ignitor
assembly from the burner.
2. Break the gas union at the burner and isolate the burner
piping from the manifold piping.
3. Seal the open end of the manifold piping with duct tape or
other means to prevent dirt from entering the manifold pipe
and/or gas controls.
4. Using a high-pressure air hose (40 to 80 PSI) flush the
burner gas ports from the flame side of the burner.
Continue to flush the burner until all dust particles are
removed.
note: If air pressure alone is not sufficient to clean the burner
gas ports, the ports may be cleaned by using the
appropriately sized bit from a NUMBERED DRILL SET.
Check the manufacturer's name stamped on the burner
AND check the type of gas the unit was designed to
use. The gas type can be found on the unit's rating
plate. With this information, use the following table to
determine the correct numbered drill bit size. Push the
bit by hand through the gas ports to clean them.
Burner
Midco Natural and Propane
5. Remove the protective cover that was placed on the
manifold piping in Step 3 and reconnect the gas union.
6. Reassemble pilot and ignitor assembly to the burner.
7. After cleaning and re-assembly, use a soap/water solution
to check for gas leaks in the piping.
8. Restore power and gas to the unit.
Gas and electric controls
Inspect for general cleanliness and tightness of electric and
mechanical connections.
Figure 41.1 - midco Burner assembly
Burner Ports
7-500.10
Gas Type Drill #
#31
Pilot & Ignitor
Assembly
Flame Rod
& Ignitor
41