White Rodgers 50M56U-751 User manual

FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY
BEFORE INSTALLING OR OPERATING THIS CONTROL COULD CAUSE
PERSONAL INJURY AND/OR PROPERTY DAMAGE.
PARTS INCLUDED
• 50M56U-751 Integrated Furnace Control
• 9-Pin Adapter Harness
• Flip Adapter Harness
• 4 – 1” Sheet Metal Screws
• 3 – 1/2” Sheet Metal Screws
• Installation Instructions
DESCRIPTION
SPECIFICATIONS & TIMINGS
ELECTRICAL RATINGS:
Input Low Voltage: 24 VAC, 60 Hz
Input Line Voltage: 120 VAC, 60 Hz, 1φ
Max Input Current: 0.45 A @ 24 VAC
Relay Contact Ratings:
Gas Valve: 1.5 A, 0.6 PF @ 24 VAC
Ignitor Relay: 1.2 A @ 120 VAC
Inducer Relay: 2.8 A @ 120 VAC
Circulator Relay: 10 FLA, 25 LRA @ 120 VAC
Humidifier Load: 1.0 A @ 24 or 120 VAC
Electronic Air Cleaner: 1.0 A @ 120 VAC
Flame Current Requirements:
Minimum current to ensure flame detection:
0.25 μA DC*
Maximum current for non-detection: 0.1 μA DC
Maximum allowable leakage resistance: 100 M
ohms
* Measured with a DC ammeter
Flame Establishing Time: 0.8 seconds maximum
Flame Failure Response Time:
2.0 seconds maximum
OPERATING TEMPERATURE RANGE:
-40° to 176°F (-40° to 80°C)
HUMIDITY RANGE:
5 to 95% relative humidity (non-condensing)
PART NO. 37-7751001
2031
50M56U-751 with Black Cover
Carrier/ICP Integrated Single Stage
120V Hot Surface Ignition Control Kit
INSTALLATION INSTRUCTIONS
50M56U-751 is an aftermarket direct replacement
control kit for Carrier and ICP single stage furnace
products with PSC blower motors.
Risk of Electric Shock.
Disconnect electric power
to system until installation
is complete. Do not use on
circuitexceedingspecified
voltage.Highervoltagewill
damage control and could
cause shock or fire hazard.
This control is not intended
for use in locations where
it may come in contact with
water.
May cause flame rollout.
Shut off main gas to
heating system until
installation is complete.
TWINNING: 50M56U-751 can be twinned. The other
control must also be a 50M56U-751 with Black
cover to ensure proper functionality.
AGENCY APPROVALS: UL USA / Canada
GASES APPROVED: Natural, Manufactured, Mixed, Liq-
uid Petroleum, and LP Gas Air Mixtures.
emerson.com/white-rodgers

WIRING
Most furnaces are serviced by simply connecting the OEM wiring
directly to the new 50M56U-751 control. Exceptions to this rule are
covered below:
NOTE: Furnaces previously serviced with Carrier 325878-751, ICM 282A, or White-Rodgers 50M56U-751 kits
may have an adapter harness already installed between the factory wiring and the control being replaced. If found,
remove the old adapter harness and replace it with the new one provided in the kit.
NOTE: Using the “Flip” harness when replacing controls other than HK42FZ018 or failure to use the “Flip” harness
when replacing HK42FZ018 will result in a miswiring that will cause a Limit / Rollout Switch Open Error (Code 33)
and eventually a Limit / Rollout Switch Lockout (Code 13).
The 11-pin inline connections for these applications are reversed or “flipped” 1 for 1 from the standard pinout. To
allow for this, the “Flip” harness connects pin 1 on the control to pin 11 in the furnace, Pin 2 on control to Pin 10 in
the furnace, etc.
9-Pin Adapter Harness
Used when replacing the following OEM controls:
HK42FZ004, HK42FZ007, HK42FZ008, HK42FZ009, HK42FZ011, HK42FZ016
11-Pin “Flip” Adapter Harness
Used when replacing the following OEM control: HK42FZ018
Furnace 2-Pin
Furnace 11-Pin
Control Board
Neutrals
Control Board
11-Pin
Control Board
2-Pin
Control Board
11-Pin
Furnace 3-Pin
Furnace 9-Pin
11
10
9
8
7
6
5
4
3
2
1
1
2
3
4
5
6
7
8
9
10
11
2

INSTALLATION
MOUNTING
NOTE: All wiring should be installed according to local
and national electrical codes and ordinances.
1. Disconnect electrical power and shut off gas supply
to unit, then remove unit access panels.
2. Mark and disconnect all wires from the existing
control, then remove existing control.
3. Mount 50M56U-751 in the unit using one of the
three mounting options noted in the Mounting
section. Be certain not to damage any components
such as wire harnesses or blower wheels when
drilling or installing screws.
4. If needed, refer to the Wiring section and select
the proper adapter harness needed to replace the
board being serviced.
5. Connect all the wires back onto the 50M56U-751
control board referencing the Wiring Diagram
section as needed.
6. Ensure all wires are secure to the control board
and unused blower speed wires are attached to
the SPARE terminals. Apply wire ties as needed to
secure wiring.
7. Verify Heat ON delay, Constant Fan Speed, Heat
OFF Delay, and Cool OFF Delay settings, as
described in the Configuration section.
8. Reinstall unit access panels and reconnect electric
power. Restore gas supply to the unit.
9. Verify unit operation in heating, cooling, and fan
only mode.
Tabs: For OEM direct mounting when
replacing controls with a tray. Secure with a
½" screw.
Corner Holes: For OEM direct mounting when
replacing controls with metal standoffs. Align
right hand side corner holes with factory sheet
metal hole locations. Secure with 2 1" screws.
Optional: Secure with 2 additional 1" screws on
left hand side (drilling required).
Custom mounting: Utilize any combination of
½" screws with mounting tabs and 1" screws
with corner holes to secure control. Tabs can
be cut off if additional clearance for mounting
is needed.
NOTE: Start all screws prior to fully
tightening to ensure proper alignment.
A
B
Optional B
C
A
B
Optional B
A
B
B
Optional
AA
3

CONFIGURATION
SELF TEST
Heat ON Delay (sec.) Constant Fan Speed Heat OFF Delay (sec.)
ON
ON
ON ON ON
ON
ON
ON
OFF
OFF
OFF OFF OFF
OFF
OFF
OFF
180 150
120* 90
25
HEAT*
FAN
4
3
2
1
4
3
2
1
4
3
2
1
4
3
2
1
4
3
2
1
4
3
2
1
4
3
2
1
4
3
2
1
1
2
3
4
1
2
3
4
*Default
SW1-1 SW1-2 SW1- 3 & 4
60*
Cool Off Delay Setting
The default cool off delay is 90 seconds. If dehumidification control via the thermostat is not desired, the cool off
delay can be changed to 5 seconds by placing a jumper between the Y/Y2 and DHUM thermostat inputs.
Automatic Configuration
50M56U-751 automatically configures its functional operation to match that of the OEM control being replaced
across a variety of Carrier and ICP applications. This automatic configuration feature allows 50M56U-751 to
accept various connections (HPS Input, Inducer Ground, or Not Connected) on Pin 3 of the 11 Pin main harness
connector. See the Wiring Diagram for additional details on connections specific to your application
Enter Self-Test immediately after control
power up by:
• Double pressing the “FAULT RECALL” button while
LED rapid flashes green.
NOTE: Control will terminate Self-Test mode if any
system fault occurs. Control will ignore any active
thermostat calls during Self-Test.
Sequence is as follows:
• LED will flash all stored fault codes five times. If there
are no faults LED will be off for 2 seconds.
• Afterward,the LEDwillslowly flashcode11 in alternate
colors (green, amber, red) to indicate Self-Test is
active. This will continue until Self-Test is complete.
• Inducer motor will turn ON and continue running until
Self-Test is complete.
• After15 seconds,the ignitorwill turnONfor15seconds,
then OFF.
• Blower motor runs at the Fan (SW1-2), Heat, and Cool
speeds respectively for 10 seconds each.
• Blower and Inducer motors turn OFF.
• Self-Test is complete, LED will display solid green to
indicate Standby mode.
4

WIRING DIAGRAM
(MED LO) (LO) (MED HI) (HI)
TWIN TERMINAL
CONNECT TO ANOTHER 50M56U-751
(COM)
COOLHEATFANSPARE-1
SPARE-2SPARE-3
TWIN
120VAC HOT
120VAC
NEUTRAL
IGNITOR
CIRCULATOR
(SEE 11 PIN DETAIL)
L2
INDUCER
PR-2
WHT
WHT
WHT
WHT
WHT
WHT
WHT
BLU
RED
IGN
IND
EAC-2
NEUTRAL
PL2
120V HUM PR-1
ELECTRONIC
AIR CLEANER
EAC-1
BLK
BLU
RED
YEL
TRANSFORMER
24V HUM
GRY
SEC-1
SEC-2
BLW
HUMIDIFIER
120VAC
L1
11 PIN WIRING DETAIL
RED YEL WHT BLK GRN GRY BLU
THERMOSTAT
R Y/Y2 W COM G DHUM Y1
HUMIDIFIER
24VAC
PIN 3: NOT CONNECTED
FLAME SENSOR
LGPS (WHEN USED)
LPS ORG
YEL
WHT
BLU
FRS1LS1DSSBVSS
(WHEN USED)
GAS VALVE
RED
RED
GRN/YEL
FRS2LS2
(WHEN USED)
(WHEN USED)
1
2
3
4
5
6
7
8
9
10
11
PIN 3: HOUSING PRESSURE SWITCH INPUT
FLAME SENSOR
HPS
LGPS (WHEN USED)
LPS ORG
BRN
YEL
WHT
BLU
FRS1LS1DSSBVSS
(WHEN USED)
GAS VALVE
WHT
RED
WHT
RED
GRN/YEL
FRS2LS2
(WHEN USED)
(WHEN USED)
1
2
3
4
5
6
7
8
9
10
11
1
2
3
4
5
6
7
8
9
10
11
FLAME SENSOR
PRESSURE OUT
(SEE 11 PIN DETAIL)
PRESSURE IN
GAS VALVE GND
LIMIT OUT
(SEE 11 PIN DETAIL)
LIMIT IN
(SEE 11 PIN DETAIL)
GAS VALVE OUT
(SEE 11 PIN DETAIL)
#DESCRIPTION
11 PIN FUNCTIONS
BLU
PIN 3: INDUCER GROUND
FRS1LS1DSSBVSS
(WHEN USED)
GAS VALVE
FLAME SENSOR
WHT
LGPS (WHEN USED)
LPS
RED
WHT
RED
GRN/YEL
ORG
YEL
WHT
INDUCER
GRN/YEL
1
2
3
4
5
6
7
8
9
10
11
FRS2LS2
(WHEN USED)
(WHEN USED)
FAULT RECALL PUSH BUTTON
DIPSWITCHES
SW1-1HEAT ON DELAY
SW1-2FAN SPEED
SW1-3&4HEAT OFF DELAY
BVSS Blocked Vent Shutoff Switch, Manual-reset, SPST -(N.C.)
DSS Dra Safeguard Switch
FRS1,2 Flame Rollout Switch - Manual Reset, SPST-(N.C.)
HPS Housing Pressure Switch, SPST-(N.O.)
LGPS Low Gas Pressure Switch, SPST-(N.O.)
LPSPressure Switch, SPST-(N.O.)
LS1,2 Limit Switch - Auto Reset, SPST (N.C.)
LEGEND
1VDC=1µA
FLAME
CURRENT
SENSE
STATUS LED
5

OPERATION
HEAT MODE
Output Standby Call for Heat Self-Check Pre-Purge Ignitor Warm-up (Adaptive, starts at 17s) Ignition Activation Period Blower Heat ON Delay (*Default) Heating until Thermostat is Satisfied Post-Purge Blower Heat Off Delay (*Default) Standby
15 s 5-21 s 2.8 s 25, *60 s 15 s 90, *120, 150, 180 s
Thermostat - W
Inducer
Pressure Switch
Ignitor
Gas Valve
Flame Sensor
Blower (Heat Speed)
Humidifier (24V)
Humidifier (120V)
EAC
LED On Amber LED - 42 Flash Green LED – Solid On
Cool On Delay
• Cool blower ON delay is 2 seconds.
Fan & Low Cool
• The constant fan speed (G) and low cool speed
(Y1) are determined by the fan speed tap selected
with dipswitch SW1-2 (heat speed is default).
• There is a 1 second blower ON delay and a 1
second blower OFF delay for a fan only demand.
• Set thermostat to Fan ON for continuous fan.
Dehumidification
NOTE: This feature requires connection to a thermostat
with a dehumidification function (DHUM terminal).
• DHUM input is reverse logic in that presence of a
24V signal = no dehumidify demand, and absence
of a 24V signal = dehumidify demand.
• Dehumidify demand with a Y1 input runs the blower
at the low cool speed selected by dipswitch SW1-2
(heat speed is default).
• Dehumidify demand with a Y / Y2 input runs the
blower at the cool speed for 10 minutes, then
reduces the blower speed from cool to low cool
for 10 minutes, then returns to the cool speed for 10
minutes.
• Alternating 10-minute cycles continue for as long as
there is a call for 2nd Stage cooling (Y2).
• When the call for cool is satisfied and there is a
dehumidify demand, the blower off delay is reduced
to 5 seconds.
Air Conditioner & Heat Pump
• Systems retrofitted with 50M56U-751 can be paired
with either a 1 or 2 stage air conditioner or heat
pump.
• When paired with a 1-stage unit, connect the Y
output from the thermostat to Y/Y2 input on the
control. For 2-stage units, connect the Y1 output
from the thermostat to the Y1 input on the control
and the Y2 output from the thermostat to the Y/Y2
input on the control.
• 50M56U-751 will provide auxiliary heating during
a heat pump defrost cycle if it receives heat and
cool calls simultaneously (W + any Y).
6

TROUBLESHOOTING
Green LED Flash Amber LED Flash Red LED Flash Error / Condition
Up to 5 Flash Codes Stored in Memory (Auto-Erased After 14 Days)
13 Limit / Roll-Out Lockout
14 Ignition Lockout - After 3 Retries
15 Ignition Lockout - After 10 Recycles
17 Ignitor Failure - Replace Ignitor
21 Gas Heating Lockout
22 Abnormal Flame Proving Signal
23 LPS - Pressure Switch Did Not Open
24 Secondary Voltage Fuse is Open
25 Reversed 120V Line Polarity
26 HPS - Pressure Switch Did Not Open
27 Bad Ground
31 LPS - Pressure Switch Did Not Close
33 Limit or Flame Rollout Switch Open
34 Ignition Failure
36 HPS - Pressure Switch Did Not Close
Flash Codes NOT Stored in Memory
12 Blower on After Power Up
Rapid Twinning Error
Solid ON Internal Fault - Replace Control
11 11 11 Component Self Test - Colors Alternate
OFF OFF OFF No Power - Check L1/L2 & SEC-1/SEC-2
41 Weak Flame Sensed
42 Normal Heat Mode (W)
43 Normal Cool Mode (Y)
44 Normal Fan Mode (G)
Rapid Control Power Up - Test Mode Entry
Solid ON Standby Mode
Two Digit Flash Codes: The 1st digit is the number of short flashes, the 2nd digit is the number of long flashes
Example: Ignition failure would display on the Red LED as 3 short flashes followed by 4 long flashes
Fault Recall
When the control is in standby mode, press and
hold the “FAULT RECALL” button (approximately 3-5
seconds) until the solid green LED turns off, then
release the button.
NOTE: While displaying the stored fault codes, the
control will ignore any new call for heat, cool or fan.
Fault Code Reset
When the control is in standby mode, press and hold
the “FAULT RECALL” button until the diagnostic LED
begins to rapid flash (approximately 7-10 seconds)
then release the button. The LED will turn off for
2 seconds after fault codes are erased. Faults will
automatically be cleared from memory after 14 days.
NOTE: If the switch is held pressed for over 10
seconds, faults will not be cleared, rapid flash will stop,
and the LED will be solid green to indicate return to
standby.
Control Reset
Control reset is automatic after 1 hour in lockout.
Removing 24 VAC power to the control for greater than
10 seconds will manually reset the control.
Flame Current Test
Set multimeter to DC volts and place leads on the
flame current sense pins. Read the voltage directly as
microamps (1 VDC = 1μA) with the burners on.
Reading results: 0.5 – 1.0 = marginal, 1.0 – 5.0 =
good.
7

emerson.com/white-rodgers
Emerson and White-Rodgers are
trademarks of Emerson Electric Co.
©2020 Emerson Electric Co.
All rights reserved.
TECHNICAL SUPPORT: 1-888-725-9797

LE DÉFAUT DE LIRE ET DE RESPECTER SOIGNEUSEMENT TOUTES LES
DIRECTIVESAVANT L’INSTALLATION OUL’UTILISATIONDE CETTECOMMANDE
PEUT CAUSER DES BLESSURES OU DES DOMMAGES MATÉRIELS.
PIÈCES INCLUSES
• Commande de fournaise intégrée 50M56U-751
• Faisceau de câbles adaptateur à 9 broches
• Faisceau de câbles d’inversion
• 4 – Vis à tôle de montage de 1 po
• 3 – Vis à tôle de montage de 1/2 po
• Directives d’installation
DESCRIPTION
CARACTÉRISTIQUES TECHNIQUES ET MINUTAGES
SPÉCIFICATIONS ÉLECTRIQUES :
Tension basse d’entrée : 24 V c.a., 60 Hz
Tension secteur d’entrée : 120 V c.a., 60 Hz, 1 φ
Courant d’entrée maximal : 0,45 A à 24 V c.a.
Paramètres du contact de relais :
Vanne à gaz : 1,5 A, 0,6 PF à 24 V c.a.
Relais de l’allumeur : 1,2 A à 120 V c.a.
Relais de l’inducteur : 2,8 A à 120 V c.a.
Relais du ventilateur : 10 FLA, 25 LRA à 120 V c.a.
Charge de l’humidificateur : 1,0 A à 24 V c.a. ou 120 V c.a.
Purificateur d’air électronique : 1,0 A à 120 V c.a.
Exigences de courant pour la flamme :
Courant minimum requis pour assurer la détection de la
flamme : 0,25 μA c.c.*
Courant maximum pour la non-détection : 0,1 μA c.c.
Résistance à la fuite maximum permise : 100 Mohms
* Mesuré avec un ampèremètre c.c.
Temps requis pour établir une flamme :
0,8 seconde maximum
Temps de réponse en l’absence de flamme :
2,0 secondes maximum
PLAGE DE TEMPÉRATURES DE MARCHE :
-40° à 176 °F (-40° à 80 °C)
PLAGE D’HUMIDITÉ :
5 à 95 % d’humidité relative (sans condensation)
NODE PIÈCE 37-7751001
2031
50M56U-751 avec couvercle noir
Trousse de commande d’allumage de surface chauffante 120 V
mono-étage intégré Carrier/ICP
DIRECTIVES D’INSTALLATION
La commande 50M56U-751 est une trousse de commande de
rechange universelle du marché des pièces de rechange pour les
fournaises mono-étage Carrier et ICP avec moteurs de ventilateur
PSC.
Risque de décharge électrique.
Débranchez l’alimentation
électrique du système jusqu’à ce
que l’installation soit terminée.
N’utilisez pas cet appareil sur des
circuitsdontla tension est supérieure
à celle indiquée. Une tension plus
élevée endommagera la commande
et pourrait présenter un risque de
décharge électrique ou d’incendie.
Cette commande n’est pas conçue
pour être utilisée dans les endroits
où elle peut entrer en contact avec
de l’eau.
Peut causer un débordement de
flamme. Coupez l’alimentation
de gaz principale au système
de chauffage jusqu’à ce que
l’installation soit terminée.
JUMELAGE : La commande 50M56U-751 peut être jumelée.
L’autre commande doit également être une 50M56U-751 avec un
couvercle noir pour assurer le fonctionnement approprié.
HOMOLOGATIONS OFFICIELLES : UL É.-U./Canada
GAZ APPROUVÉS : Gaz naturel, manufacturé, mélangé, pétrole
liquide et mélanges de GPL et air.
emerson.com/white-rodgers

CÂBLAGE
L’entretien de la plupart des fournaises se fait par le simple branchement
direct du câblage d’origine à la nouvelle commande 50M56U-751.
Les exceptions à cette règle sont données ci-dessous :
REMARQUE : Les fournaises précédemment entretenues avec les trousses Carrier 325878-751, ICM 282A ou White-Rodgers
50M56U-751 peuvent avoir un faisceau adaptateur installé entre le câblage d’usine et la commande remplacée. Dans ce cas,
retirez l’ancien faisceau adaptateur et remplacez-le par le nouveau faisceau fourni dans la trousse.
REMARQUE : L’utilisation d’un autre faisceau d’inversion pour le remplacement des commandes que le HK42FZ018 ou le
fait de ne pas utiliser le faisceau d’inversion pour le remplacement de HK42FZ018 entraîne un câblage inapproprié qui cause
une erreur d’interrupteur de fin de course/débordement (Code 33) et finit par un verrouillage de l’interrupteur de fin de course/
débordement (Code 13).
Les branchements intégrés à 11 broches de ces applications sont inversés 1 pour 1 à partir de la fiche normale. Pour
permettre ceci, la broche 1 du faisceau d’inversion sur la commande se branche sur la broche 11 de la fournaise, la
broche 2 de la commande sur la broche 10 de la fournaise, etc.
Faisceau de câbles adaptateur à 9 broches
Utilisé pour le remplacement des commandes d’origine ci-dessous :
HK42FZ004, HK42FZ007, HK42FZ008, HK42FZ009, HK42FZ011, HK42FZ016
Faisceau de câbles d’inversion à 11 broches
Utilisé pour le remplacement de cette commande d’origine : HK42FZ018
2 broches de la
fournaise
11 broches de la
fournaise
Neutres du
panneau de
commande
11 broches du
panneau de
commande
2 broches du
panneau de
commande
11 broches du
panneau de
commande
3 broches de la
fournaise
9 broches de la
fournaise
11
10
9
8
7
6
5
4
3
2
1
1
2
3
4
5
6
7
8
9
10
11
10