6139716-UIM-A-0422
Johnson Controls Ducted Systems 13
Section X: Maintenance
Inspect filters at least once per month, and clean or replace them when
they become dirty. The frequency of cleaning depends upon the hours
of operation and the local atmospheric conditions. Clean filters keep
unit efficiency high.
Coil cleaning
If cleaning the coil is necessary, clean with water only. As an alternative
to water, Evap-Green by Nu-Calgon is the only pH neutral coil cleaner
approved for use when it is properly diluted. Ensure to thoroughly rinse
the cleaned coils after using Evap-Green.
Lubrication
The bearings of the blower motor are permanently lubricated.
Condensate drains
During the cooling season, check the condensate drain lines to be sure
that condensate is flowing from the primary drain but not from the sec-
ondary drain. If condensate ever flows from the secondary drain, shut
off the unit immediately and clean the condensate pan and drains to
insure a free flowing primary drain.
Section XI: 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 the coil
for static pressure measurements, run only the fan to ensure a dry coil.
Drill a hole 12 in. away from the air handler in the supply air duct.
You must take the return air pressure reading between the indoor coil
and the air handler.
External duct static
To determine total external system static pressure, complete the
following:
1. Drill a hole 12 in. away from the air handler in the supply air duct.
You must take the return air pressure reading between the indoor
coil and the air handler.
2. Measure the supply air static pressure. Record this positive
number.
3. Measure the return air static pressure. Record this negative
number.
4. Treat the negative number as a positive, and add the two numbers
together to determine the total external system static pressure.
CAUTION
Ensure adequate precautions are taken to protect electrical compo-
nents from liquid.
NOTICE
See Table 14 for air handling unit airflow data (CFM).
!
Figure 13: Duct static measurements
To Next Page
Loading...
Need help?
General
