6
APPLICATION & OPERATION NOTES
loads are present on specific connector terminals. It is critical
that system wiring match one of the scenarios outlined in the
Wiring Diagrams section and that all system components
(such as inducer motors and pressure switches) are operating
properly prior to automatic configuration taking place.
Automatic configuration occurs during the first power up and
is verified at the next power up. After the same application
is detected 2 consecutive times, the corresponding
configuration is written to memory and automatic
configuration will no longer occur at power up. However once
stored, the automatic configuration can always be cleared
using menu option 5 (CHC). If an automatic configuration
error code (E41) is reported, verify all wiring connections
are correct, all components in the system are present and
functioning properly before power cycling the control and
attempting another automatic configuration process.
Note: A single valid automatic configuration is sufficient to
proceed with control installation and verification testing.
Blower Type Selection and Speed Settings
50M56X-843 is able to replace furnaces with PSC or ECMx
(constant torque) blower motors. The motor type present in
the furnace must be configured by the installer based on the
options in the Configurations Menu option number 6 (BLr).
PSC options include 2 speed (heat & cool) or 3 speed (heat,
cool, and fan). ECMx options include 2 (heat & hi-cool),
3 (heat, hi-cool, & fan), 4 (heat, lo-cool, hi-cool, & fan), 5,
and 9 speed options. For 5 (F01 – F05) and 9 (F01-F09)
speed blowers use the Configuration Menu to select the
appropriate speed for cool, heat, and fan. For 2 speed motors
constant fan (G) calls will default to the heat speed.
Note: If additional fan speed connections are available via the
motor wiring but not in use, the system can be upgraded to
operate with additional blower speeds in certain scenarios, for
example constant fan, dehumidification, and/or high and low
cooling. Reference OEM literature for more information on fan
speed connections and approximate CFM.
Roll Out Configuration
Certain Trane, American Standard, and York (including York
P3UR / PCLU) furnaces do not have an individually monitored
rollout switch in their main harness wiring configuration and
instead place the rollout switch in series with other limit
switches for example the high limit (HL) switch. As these
models share the same connector #8 in the Wiring Diagrams
with other OEMs that utilize a separately monitored rollout
switch between pins 5 and 11. Instead of using a physical
shunt jumper or wire accessory to bypass the rollout input for
these applications, changing Configuration Menu setting
number 21 (rOb) to Yes will digitally bypass the rollout inputs.
Note: Failure to bypass the rollout input for certain Trane,
American Standard, and York furnaces that do not require
one will disable furnace operation and result in a rollout
switch open error (E07).
OEM Wiring Terminal Spacing Connector
Retrofit (Special Case)
Some OEM furnaces, for example Trane and American
Standard, have a plastic connector housing that groups
together line and neutral spade terminals. This is done so
they can plug onto OEM controls all at once saving time
on the manufacturer’s production line albeit at a cost of
expanded spacing and therefore limited room for additional
accessory terminals such as electronic air cleaners and 120V
humidifiers.
If encountered during replacement, simply snip off the wire
near the plastic connector housing, strip the insulation, and
crimp on one of the provided ¼” female spade terminals.
Then connect the black wires to Line terminals (Line-H,
XFMR-H, & CIRC-H) and connect white wires to neutral
terminals.
Note: The 3 line connections (Line-H, XFMR-H, & CIRC-H)
are electrically continuous as are all neutral terminal
connections. As such, the order of connection is arbitrary in
a retrofit scenario as long as all 120V line connections (black
wires) are connected to a line terminal and all 120V neutral
connections (white wires) are connected to a neutral terminal.
FLAME SENSOR KIT Required on RHEEM/
RUUD Models (1994 and earlier)
If the control being replaced has 2 green lights (no amber
light), and a date code of 3294 or earlier, a Flame Sensor Kit,
RHEEM part number 62-24044-71 is required (not available
through White-Rodgers).
Replacing Previously Installed Universal
Controls
When replacing a failed Resideo/Honeywell H9200U1000,
ICM ICM2812-KIT & ICM-2812, or White-Rodgers 50M56U-
843 & 50X57-843 (unlikely scenario), identify and remove any
wiring adapter harness between OEM furnace wiring and the
failed universal control prior to replacement with 50M56X-843.
Status Display During Active Calls
During an active call for heat, cool, or constant fan, the
display will alternate between up to 3 status indicators. As
outlined in Table 2, the first indicator will display the active
call from the thermostat. If applicable the active motor speed
selection will also be displayed alongside flame current (in
heating mode only). If an active error code is present, it
will be displayed in an alternating pattern with the others
discussed above.
