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SERVICE REMINDER
INSTALLATION
NUMBER:
DATE:
SERVICE
Tampa Sales District
The Trane Company
9208 Palm River Road
Suite 301
Tampa, FL 33619
(813) 621-7070
4-01
10/17/01
TO: ALL AUTHORIZED TRANE DEALERS AND SERVICERS
SUBJECT:
TROUBLESHOOTING SILICON NITRIDE IGNITION INTEGRATED
FURNACE CONTROLS: “9 FLASH” LOCKOUTS, HSI FAILURES
MODELS AFFECTED: *DD/*UD/*DX/*UX/*DY/*UY SILICON NITRIDE MODELS
INTRODUCTION:
(See also FURN-TRN-SB-12). This bulletin provides additional information
regarding failure modes, troubleshooting, and factory corrective actions. Detected faults have caused “ 9
Flash” lockouts and premature hot surface igniter failures. Some of these faults are field repairable and
other faults required new software to resolve the problem. This new software is being incorporated in
today’s controls, which are more “fault tolerant”. (See IFC date code reference table on page 3). The
notes below and previous service bulletins can be used to determine if the fault can be repaired. When all
wiring faults have been eliminated, and a field installed “electrical noise filter” does not solve the
problem (9 flash or solid LED lockouts) a new control with revised software needs to be installed.
DISCUSSION:
• Factory Miswire: One fault discovered is a factory miswired 12-pin plug in the low voltage wire
harness. The green, ground wire was inserted into the wrong hole (#5) in the wire harness. The
proper location for the ground wire is in hole #8. (See Fig.1, p.3) This causes an error in the voltage
regulation to the silicon nitride HSI. The result is excessive voltage output to the igniter and
premature igniter failure. The problem is believed to be limited to single stage furnaces (TDD/TUD-C
and TDX/TUX-C).
! This fault is detected by measuring voltage between the “Line N” terminal and the “B/C”**
terminal (low voltage “Common”) on the Integrated Furnace Control (I.F.C.). If miswired,
transformer secondary voltage will be measured. (See Fig. 1, p.3).
** Some models use “B” to denote “Common”, some use “C” and some use “B/C”
!
Factory Corrective Action - 12 Pin Plug Miswire: A fixture is being used in the wiring
harness area that will prevent inserting a wire into the unused holes of the 12-pin plug. This
improvement went into effect on the 90+ furnace line FW09 of 2001 (Z09 date codes) and
also on the 80+ lines on FW11 of 2001 (Z11 date codes).
!
Field Corrective Action
1.
2.
3.
4.
Turn off the electrical power to the furnace.
Using a pin extraction tool - remove the green wire from hole #5 and re-insert it into hole #8.
Unplug the hot surface igniter.
Measure the resistance of the igniter while it is still cold. A good igniter will measure between 11
and 18 ohms. If the igniter resistance is above 18 ohms, replace it with IGN00104.
5. After ensuring a good igniter is properly installed in the furnace and all wiring is properly
reconnected, turn the electrical power back on.
6. Re-check the voltage from “Line N” to “B/C”. It should be less than 2 volts. If not, skip steps 7
and 8 and go directly to Field Wiring Faults below.
7. Initiate a call for heat.
8. Measure the output voltage to the igniter while it is heating (the igniter has to be electrically
connected for the IFC to work properly.) A properly functioning IFC, with a good igniter will
indicate a range of 90 to 110 volts on the first ignition cycle. This range should reduce with each
subsequent cycle (“learn down”) as long as the furnace lights reliably on the first try of each cycle.
(Refer to the training manual Gas Furnace Silicon Nitride Igniter Models, pub. no. 34-3405-04).
Note: When checking this output with a digital voltmeter, the display will normally fluctuate over
a 20 to 30 volt range if the power supply is working properly. The needle will “bounce” on an
analog meter. Check the output voltage to the igniter during 2 or 3 complete ignition sequences t o
ensure the power supply is “learning down”.
9. If there are no detected wiring faults and the voltage output to the igniter is steady (nonfluctuating) at or near the supply line voltage, then the voltage regulation circuit on the IFC has
failed and the IFC needs replaced. (See Field Wiring Faults below.)
Caution: Make sure the IFC being installed is correct for the furnace being serviced. See t h e
IFC-to-Furnace-Family cross reference at the end of this bulletin.
Field Wiring Faults
It has been discovered that a poor Earth ground connection can result in early HSI failures in Silicon
Nitride systems. This can be easily detected by measuring the voltage between the IFC “Line N”
terminal and the IFC low voltage “C” terminal. The measured voltage should be less than 2 volts. Some
furnaces will have a measured voltage between “Line N” and “C” when the only fault is a poor Earth
ground. A good Earth ground will prevent this from being a problem. If the voltage measured between
“Line N” and “C” is greater than 2 volts, correct the ground circuit. Note: This fault should not yield a
“9 flash” lockout but will yield a high output voltage to the igniter.
Other Faults: Open or grounded HSI wiring harness. There have been reports of the HSI harness
lying against a hot surface inside the furnace and then the insulation melting. This ground condition
may not cause a circuit breaker to trip, but can cause excess current flow through the voltage regulation
circuit. This may cause the triac on the IFC board to fail. Normally the triac will fail “open” and no
voltage will go to the igniter. However, a shorted triac will apply 120 VAC to the igniter and may cause
an early igniter failure. A visual inspection should reveal this fault. After repairing the wire, perform
steps 3 through 8 above to check out the igniter and igniter power supply.
There have been a few reports of one of the igniter power leads being open (pinched or broken). This
fault could give an intermittent 9 flash lockout. A continuity check of the igniter leads with the cable
ties removed and the wires being flexed should reveal this fault, if present. Again, after repairing the
harness, perform steps 3 through 8 above.
Factory Corrective Action: As soon as reported, special attention was given to wire dress on the
assembly lines. A design change has been made to change the routing of the igniter harness to the
channel formed in the front of the furnace by the cabinet wrapper door flange.
CONCLUSION:
A control checkout survey (sample attached) is being included with all replacement controls. Please fill
this form out when repairing the furnace. Each parts distributor is required to return these controls t o
the manufacturer for analysis. The survey form will greatly aid in identifying problems and solutions.
Failed controls must be returned to the local parts distributor when claimed in warranty.
This bulletin is intended to be informative. Any faults deemed to be factory error or IFC design related
need to be brought to the attention of the local Field Service Representative.
ISSUED BY:
AFTER SALE SUPPORT -TRENTON
FIGURE 1
Measure voltage from
“Line N” to the “C”
terminal
DATE CODE REFERENCE (NEW SOFTWARE IMPROVEMENTS)
PART NUMBER
CNT03076
CNT03077
CNT03078
CNT02871
CNT02536
PART D/C
0049
0101
0101
0103
0111
FURNACE MODEL
*DD/*UD-C, DX/UX-C
*DD/*UD-R
*DD/*UD-R9V
*DX/*UX-R9xxV
*DY/*UY-RV-V
FURNACE DATE CODE
Z10
Z10
Z10
Z10
Z18
*CNT02536 does not have a 9 flash code fault and has not exhibited the same problems as the other
silicon nitride controls. However, the software revisions for fault tolerant circuitry are being
incorporated into these controls as well. All current replacement parts in Memphis stock have revised
software.
IFC-TO-FURNACE MODEL FAMILY CROSS REFERENCE
MODEL FAMILY
Approximate First
Production Date (Date
Code)
TRANE P/N
W-R P/N
Trane DWG#
IGN
TYPE
ONE STAGE IFC
FCA/FUA-A-A0…A1 & CUD-A-A1…A3
*DE/*UE-A-K0…K1 & FCA/FUA-A-E0 &
KIT03793
*DE/*UE-K2 and later & CUB (current production)
XE-80 *DD/*UD-C-A1…B0
XE-80 *DD-C-C0…C1 & *UD-C-H0…H1
XE-80 *DD-C-C3…C4 & *UD-C-H3...H4
XE-80 *DD/*UD-C-J0 and later
Nov. '97 (M47 )
1991
July '95
April 29, '96 (L17)
FW15-99 (P15)
CNT02789
CNT01309
CNT01848
CNT02182
**CNT03076
50A55-571
50A50-405
50A50-471
50A50-473
50A65-475
D341122P01
D340035P01
D340774P01
D330930P01
D341396P01
SiC
SiC
SiC
SiC
SiNi
XE-90
XE-90
XE-90
XE-90
XE-90
XE-90
Nov. '92
July '95
April 29, '96 (L17)
July, '98 (N31)
July, '98 (N30)
April '99 (P17)
CNT01616
CNT01849
*CNT02183
**CNT02891
CNT02854
**CNT03076
50A50-406
50A50-472
50A50-474
50A55-474
50A65-474
50A65-475
D340354P01
D340790P01
D330934P01
D341235P01
D341213P01
D341396P01
SiC
SiC
SiC
SiC
SiNi
SiNi
*DC/*UC-C-A, *DX/*UX-C-A
*DC/*UC-C and *DX/*UX-C-BO …B2
*DC/*UC-C and *DX/*UX-C-B
*DC/*UC-C and *DX/*UX-C-B
*DX/*UX-C-C0
*DX/*UX-C-C1 and later
1991
Mar, 11, '96
TWO
XL-80 *DD/*UD-R
XL-80 *DD/*UD-R
XL-80 *DD/*UD-R
CNT01309 50A50-405
CNT02181 50A50-571
STAGE IFC ( STANDARD
1991
April 29, '96 (L17)
Sept. '99 (P38)
1992
Oct. '95 (K43)
Sept. '96
Sept. '99 (P38)
Aug. '94
Sept. '96
Aug. '97
Oct. '98
MODELS )
CNT01308 50A51-405 D340021P01 SiC
CNT02184 50A51-495 D330937P01 SiC
**CNT03077 50M61-495 D341418P01 SiNi
TWO STAGE IFC ( VARIABLE
XV-80 *DD/*UD-R9V-A1
XV-80 *DD-R9V-B0...C3 & *UD-R9V-A1...H0
XV-80 *DD-R9V-C4 & *UD-R9V-H4
XV-80 *DD-R9V-D0 & *UD-R9V-J0 and later
XV-90 *DY/*UY-R9V-A0…A3
XV-90 *DY-R9V-A4, *UY-R9V-H4
XV-90 *DY/*UY-R9V-V
XL-90 *DX/*UX-R-V
D340035P01 SiC
D330927P01 SiC
SPEED MODELS )
CNT01523
CNT01819
CNT02223
**CNT03078
CNT01819
**CNT02223
**CNT02536
**CNT02871
50A51-505
50A51-506
50A51-507
50V61-507
50A51-506
50A51-507
50A61-605
50V65-495
D340236P01
D340641P01
D340949P01
D341420P01
D340641P01
D340949P01
C341033P01
D341232P01
*Universal replacement for 1 stg SiC IFC's (Also used in KIT05216 Radiant Sense to Flame Rectification Conversion)
**Current replacement part (CNT02789 and CNT02891 are currently superseded by CNT02183
SiC
SiC
SiC
SiNi
SiC
SiC
SiNi
SiNi
INTEGRATED FURNACE CONTROL RETURN CHECKLIST
Please take time to fill out this checklist and return it with the defective control so
a diagnosis and evaluation can be made.
Dealer:
Furnace Model:
City:
Customer Name:
Serial Number:
State:
Installation Type:
__ New Construction
__ Existing Residential Home
__ Commercial
Fuel Type:
__ Natural Gas
__ Liquid Petroleum
Installed Date:
Today’s Date:
Mode of Operation:
__ Heating
__ Cooling
__ Continuous Fan
The observed problem was:
___ No response from the control (Dead)
___ No inducer operation
___ No igniter operation, igniter OK.
___ Igniter will not turn off
___ No gas valve operation after igniter warm-up
___ No flame sensed after gas ignition.
___ Flame goes out after some period of operation.
___ No blower operation after gas ignition
___ No blower operation in cooling mode
___ No blower operation in continuous fan operation.
___ No high stage operation (two stage models only)
___ Other not listed. Explain:
_________________________________________________
_________________________________________________
_________________________________________________
Failed Control Part Number: ________________________________
New Control Part Number: ________________________________
When does the Problem
usually occur:
____ Morning
____ Afternoon
____ Evening
____ Random
____ Recovering from
setback
Furnace Grounding: What is
measured voltage from:
Line “H” at IFC to “C”
terminal? _______ volts
Was the flame current
measured?
___ Yes
___ Micro Amps DC
___ No
Line “N” at IFC to “C”
terminal? _______ volts
Where is the furnace located?
Has the control been replaced before?
Closet _ Attic _ Garage _
Utility Room _ Basement _
___ Yes … how many times ___?
___ No
Electronic Air Cleaner installed?
___ Yes
___ No
How is the furnace installed?
Upflow _ Downflow _
Horizontal _
Check the appropriate line to indicate the fault light
flash mode when the problem was observed.
__ 1 Flash Slow Rate
__ 1 Flash Fast Rate
__ 2 Flashes
__ 3 Flashes
__ 4 Flashes
__ 5 Flashes
__ 6 Flashes
__ 7 Flashes
__ 8 Flashes
__ 9 Flashes
__ Light ON Continuously
__ Light OFF Continuously
ISSUED BY: Tom Menard, Field Service Representative.
Are there any unusual conditions
that have occurred prior to
replacement:
___ Power outage
___ Brown out
___ Lightning storm
___ Other
_______________________
_______________________
Describe any unusual electrical or electronic
systems in the building (lighting control,
audio/video, generator, computer networks). Use the
back if necessary.
________________________________________
________________________________________
____________________________________________________