Maintenance And Service - Carrier Comfort 48VT-C Owner's Information Manual

90
STEP 1
Defrost Mode
When your heat pump is providing heat to your home or office and
the outdoor temperature drops below 45F (7.2C), moisture may
begin to freeze on the surface of the coil. If allowed to build up,
this ice would impede airflow across the coil and reduce the
amount of heat absorbed from the outside air. So, to maintain
energy- -efficient operation, your heat pump has an automatic
defrost mode.
The defrost mode starts at a preset time interval of 60 minutes,
although, it may be reset to 30, 90 or 120 minutes. Defrost will
start at the preset time only if the ice is sufficient to interfere with
normal heating operation.
After the ice is melted from the coil, or after a maximum of 10
minutes in defrost mode, the unit automatically switches back to
normal heating operation.
Do not be alarmed if steam or fog appears at the outdoor unit
during defrost mode. Water vapor from the melting ice may
condense into a mist in the cold outside air.
During certain weather conditions such as heavy snow and freezing
rain it is not uncommon for ice to build up on the unit grille. This
is normal for these weather conditions. Do not attempt to remove
the ice from the unit grille. This condition will not affect the proper
function of the unit and will clear within a few days.
Emergency Heat Mode
If you should have problems with the heat pump portion of your
system, this mode allows your supplemental gas heating source to
keep your home or office warm until your heat pump can be
serviced.

MAINTENANCE AND SERVICE

This section discusses maintenance that should be performed on
your system. Most maintenance should be performed by your
dealer. You, as the owner, may wish to handle some minor
maintenance for your new unit.
Routine Maintenance
All routine maintenance should be handled by skilled, experienced
personnel. Your dealer can help you establish a standard procedure.
For your safety, keep the unit area clear and free of combustible
materials, gasoline, and other flammable liquids and vapors.
To assure proper functioning of the unit, flow of condenser air
must not be obstructed from reaching the unit. Clearance from the
top of the unit is 48 in. (1219 mm). Clearance of at least 36 in.
(914 mm) is required on sides except the power entry side (42 in.
[1067 mm] clearance) and the duct side (12 in. [305 mm]
minimum clearance.
Maintenance and Care for the Equipment Owner
Before proceeding with those things you might want to maintain
yourself, please carefully consider the following:
STEP 2
Fig. 7 - - To Shut Off Unit Electric Cooling
FIRE, EXPLOSION, ELECTRICAL SHOCK AND
CUT HAZARD
Failure to follow this warning could result in personal
injury, death or property damage.
1. Turn off gas supply first, then all electrical power to your
2. When
Air Filters
The air filter(s) should be checked
changed or cleaned whenever it becomes dirty. Dirty filters
produce excessive stress on the blower motor and can cause the
motor to overheat and shut down.
This unit must have air filters in place before it can be operated.
These filters can be located in one of at least two places. In many
applications, the installer will provide return air filter grilles
mounted on the wall or ceiling of the conditioned structure. In the
instance of filter grilles, the filters can simply be removed from the
grille and replaced.
The other typical application is an accessory filter rack installed
inside the unit itself. The following information is given to assist in
changing filters used in these internal filter racks.
Filter kits are available as a purchased accessory or a factory
installed option. The same filter kit is included with the accessory
economizers and factory installed economizers.
48VT Unit Size
36-060/090*
48-090/115/130
60-090/115/130*
*Units with bent indoor coil.
7
WARNING
!
unit and install lock- -out tag before servicing or per-
forming maintenance.
removing access
maintenance functions inside your unit, be aware of
sharp sheet metal parts and screws. Although special care
is taken to reduce sharp edges to a minimum, be
extremely careful when handling parts or reaching into
the unit. Wear safety glasses, gloves, and appropriate
protective clothing.
Table 1 – Replacement Filter Sizes
Filter Size in. (mm)
24-040/060
(508 x 305 x 25 mm)
30-040/060
(508 x 305 x 25 mm)
1 each 24 x 16 x 1 (610 x 406 x 25),
24 x 18 x 1 (610 x 457 x 25)
1 each 24 x 14 x 1 (610 x 356 x 25),
42-060/090
24 x 16 x 1 (610 x 406 x 25)
1 each 24 x 14 x 1 (610 x 356 x 25),
24 x 16 x 1 (610 x 406 x 25)
1 each 24 x 16 x 1 (610 x 406 x 25),
24 x 18 x 1 (610 x 457 x 25)
MAIN
ON
OFF
STEP 3
A07797
panels or performing
every 3 or 4 weeks and
2 each 20 x 12 x 1
2 each 20 x 12 x 1