PMGB0406B rev.1
29
12. Maintenance
Coil Cleaning
Lubrication
Condensate Drains
Filters must be cleaned or replaced when they become dirty. Inspect at least once per month. The frequency
of cleaning depends upon the hours of operation and the local atmospheric conditions. Clean
¿
lters keep unit
ef
¿
ciency high.
If the coil needs to be cleaned, use water to clean.
The bearings of the blower motor are permanently lubricated.
During the cooling season check the condensate drain lines to be sure that condensate is
À
owing from the
primary drain but not from the secondary drain. If condensate ever
À
ows from the secondary drain the unit
should be promptly shut off and the condensate pan and drains cleaned to insure a free
À
owing primary drain.
13. Air System Adjustment
To check the Cubic Feet per Minute (CFM), measure the external duct static using a manometer and static
pressure tips.
To prepare coil for static pressure measurements, run the fan only to assure a dry coil.
NOTICE
Refer to Table 11 for coil Air Flow Data (CFM)
Drill 2 holes, one 12” away from the air handler in the supply air duct and on 12” away from the air handler
in the return air duct (before any elbows in the duct work). Insert the pressure tips, and energize the blower
motor. See Table 11 to determine the air
À
ow, and make the necessary adjustments to keep the CFM within
the air
À
ow limitations of the coil.
External Duct Static
Measure the supply air static pressure. Record this positive number. Measure the return air static pressure.
Record this negative number. Treat the negative number as a positive, and add the two numbers together to
determine the total external system static pressure. If a
¿
lter rack is installed on the return air end of the air
handler or indoor coil section, make sure to measure the return air duct static between the
¿
lter and the indoor
coil.
Figure 11. Duct Static Measurements
(Ins)DX-Kit̲4e-rev1.indd C-29
(Ins)DX-Kit̲4e-rev1.indd C-29
2016/11/25 15:32:47
2016/11/25 15:32:47