13
6. Slowly lower the cooling temperature until first stage COOL
(LOW COOL) starts. The blower, both fans, and first stage
compressor should now be operating. Allow the unit to
run 10 minutes, make sure cool air is being supplied by
the unit.
7. Lower the cooling temperature further until second stage
COOL (HIGH COOL) starts. The blower, both fans, and both
compressors should now be operating. Allow the unit to
run 10 minutes, make sure cool air is being supplied by
the unit.
8. Turn the temperature setting to the highest position,
stopping the unit. The indoor blower will continue to run
for 65 seconds.
9. Turn the thermostat system switch to “OFF” and
disconnect all power when servicing the unit.
S
TART
-
UP
P
ROCEDURE
AND
C
HECKLIST
FOR
2 S
PEED
M
ODELS
:
Models with a V in the 11th position of the model number.
For 2 speed models, the indoor blower will operate on low speed
when in “Fan Only” mode or while in first stage “Cooling” mode.
Unit will operate on high speed in “Heating” mode and while in
second stage “Cooling” mode.
The start-up procedure is the same as for “Air Conditioning Start-
up Procedure” with the understanding that in Step 6, the indoor
blower will run at low speed (~1175 motor rpm) and in Step 7, the
indoor blower will operate at high speed (~1775 motor rpm).
LOW AMBIENT COOLING NOTES:
For 15 and 20 ton models:
While in the Cooling Mode, to prevent
frost from forming on the evaporator while the unit is operating in
outdoor temperatures of 65°F or lower, it is recommended that a
low ambient kit (LAKT-03) is used. This is strongly recommended
for 2 Speed models due to the lower airflow while in the first
stage of cooling. To further protect the compressor from damage
during low ambient conditions, a Freezestat Kit (FSK01) can be
added that turns the compressor off when the evaporator
temperature drops too low.
For 25 ton models:
The 25 ton units are equipped with a control
that shuts off one condenser fan when the outdoor temperature
is 44° F or below. This is to assist low ambient cooling down to
24°. An optional Low Ambient kit, LAKT05, is required below 24°
which will enable reliable cooling to occur to a minimum ambient
temperature of zero °F.
It is recommended that all single speed models be equipped with
a Freezestat kit, FSK02A, to provide extra protection for the
compressor from damage that may occur during periods of low
ambient operation. For 25 ton 2 Speed Models only, the freezestat
comes as standard equipment.
HIGH VOLTAGE!
D
ISCONNECT
ALL
POWER
BEFORE
SERVICING
OR
INSTALLING
THIS
UNIT
. M
ULTIPLE
POWER
SOURCES
MAY
BE
PRESENT
. F
AILURE
TO
DO
SO
MAY
CAUSE
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
.
WARNING
F
INAL
S
YSTEM
C
HECKS
10. Check to see if all supply and return air grilles are adjusted
and the air distribution system is balanced for the best
compromise between heating and cooling.
11. Check for air leaks in the ductwork. See Sections on
Air
Flow Adjustments.
12. Make sure the unit is free of “rattles”, and the tubing in
the unit is free from excessive vibration. Also make sure
tubes or lines are not rubbing against each other or sheet
metal surfaces or edges. If so, correct the trouble.
13. Set the thermostat at the appropriate setting for cooling
and heating or automatic change over for normal use.
14. Be sure the Owner is instructed on the unit operation, filter,
servicing, correct thermostat operation, etc.
MAINTENANCE
HIGH VOLTAGE!
D
ISCONNECT
ALL
POWER
BEFORE
SERVICING
OR
INSTALLING
THIS
UNIT
. M
ULTIPLE
POWER
SOURCES
MAY
BE
PRESENT
. F
AILURE
TO
DO
SO
MAY
CAUSE
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
.
WARNING
T
O
PREVENT
PERSONAL
INJURY
OR
DEATH
DUE
TO
IMPROPER
INSTALLATION
,
ADJUSTMENT
,
ALTERATION
,
SERVICE
OR
MAINTENANCE
,
REFER
TO
THIS
MANUAL
. F
OR
ADDITIONAL
ASSISTANCE
OR
INFORMATION
,
CONSULT
A
QUALIFIED
INSTALLER
,
SERVICE
AGENCY
OR
THE
GAS
SUPPLIER
.
WARNING
