Control And Safety Switch Adjustment - Trane *UH2B060A9V3VA Installer's Manual

Installer's Guide
NOTE TO INSTALLER
Review warnings and the contents of USER'S INFORMA-
TION MANUAL with the homeowner when installation is
complete and equipment is ready to be turned over to the
homeowner for normal operation.
CONTROL AND SAFETY SWITCH
ADJUSTMENT
LIMIT SWITCH CHECK OUT
The limit switch is a safety device designed to close the Gas
Valve should the Furnace become overheated. Since proper
operation of this switch is important to the safety of the unit,
it must be checked out on initial start up by the
installer.
To check for proper operation of the Limit Switches, set the
Comfort Control to a temperature higher than the indicated
temperature to bring on the Gas Valve. Restrict the airflow
by blocking the return air or by disconnecting the blower.
When the Furnace reaches the maximum outlet temperature
as shown on the rating plate, the burners must shut off. If
they do not shut off after a reasonable time and overheating
is evident, a faulty Limit Switch is probable and the Limit
Switch must be replaced. After checking the operation of the
Limit Control, be sure to remove the paper or cardboard from
the return air inlet, or reconnect the blower. Refer to the
Service Facts for additional instructions.
INDOOR BLOWER TIMING
WARNING
!
ELECTRIC SHOCK HAZARD
DISCONNECT POWER TO THE UNIT BEFORE REMOVING
THE BLOWER DOOR. ALLOW A MINIMUM OF 10 SECONDS
FOR IFC POWER SUPPLY TO DISCHARGE TO 0 VOLTS.
FAILURE TO FOLLOW THIS WARNING COULD RESULT IN
PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
Heating: The Integrated Furnace Control (IFC) controls the
Variable Speed Indoor Blower. The blower "on" time is fixed
at 45 seconds after ignition. The FAN-OFF period is field
selectable by dip switches #1 and #2 located on the Inte-
grated Furnace Control between the 5-pin and 9-pin wire
connectors. The delay may be set at 60, 100, 140, or 180 sec-
onds. The factory setting is 100 seconds (See unit wiring
diagram).
Cooling: The fan delay-off period is set by dip switches on the
Integrated Furnace Control. The options for cooling delay off
is field selectable by dip switches #5 and #6.
The following table and graph explain the delay-off settings:
This unit is equipped with a blower door switch which cuts
power to the blower and Gas Valve causing shutdown when
the door is removed.
ROOM AIR COMFORT CONTROL
HEAT ANTICIPATOR ADJUSTMENT
Set the Comfort Control heat anticipator according to the
current flow measured, or the settings found in the notes on
the Furnace wiring diagram (found in the SERVICE FACTS
or inside the furnace casing).
42
Table 22. FAN OFF -- DELAY OPTIONS
SWITCH SETTINGS
5 - OFF 6 - OFF
5 - ON 6 - OFF
5 - OFF 6 - ON
5 - ON 6 - ON
* - This setting is equivalent to BAY24X045 relay
benefit.
** - This selection provides ENHANCED MODE,
which is a ramping up and ramping down of the
blower speed to provide improved comfort, quiet-
ness, and potential energy savings. See Wiring
Diagram notes on the unit or in the Service Facts
for complete wiring setup for ENHANCED MODE.
The graph which follows, shows the ramping
process.
See Wiring Diagram on the unit or in the Service Facts
for complete wiring setup for Enhanced Mode.
80%
Dehumidify
50%
Fast Cooling
OFF
1 7.5
minute minutes
Figure 66
AIRFLOW ADJUSTMENT
WARNING
!
CARBON MONOXIDE HAZARD
OPERATION WITH THE DOOR REMOVED OR AJAR CAN
PERMIT THE ESCAPE OF DANGEROUS FUMES. ALL
PANELS MUST BE SECURELY CLOSED AT ALL TIMES FOR
SAFE OPERATION OF THE FURNACE.
FAILURE TO FOLLOW THIS WARNING COULD RESULT IN
PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
Check inlet and outlet air temperatures to make sure they
are within the ranges specified on the Furnace rating name-
plate. If the airflow needs to be increased or decreased, see
the Service Facts for information on changing the speed of the
blower motor.
NOMINAL
SELECTION
AIRFLOW
NONE SAME
1.5 MINUTES 100% *
3 MINUTES 50%
Enhanced
50 - 100%
Mode**
100% if necessary
50%
Efficiency
OFF
3
minutes
18-CD26D1-10