background image

SERVICE AND TECHNICAL SUPPORT MANUAL

Gas Furnace: N9MSB

Specifications  subject to change without notice.

14

440 04 4413 03

Table 5

COOLING AIR DELIVERY - CFM (with filter 

1

)

SIZE

RETURN

 

AIR

CONNECTION

WIRE

LEAD

COLOR

COOL

-

ING

TONS

CFM

/TON

TEST

 

AIRFLOW

 

DELIVERY

 

@

 

VARIOUS

 

EXTERNAL

 

STATIC

 

PRESSURES

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

401410

SIDE/BOTTOM

Black

2.5

388

1145

1100

1060

1015

970

920

860

785

680

615

Blue

2.0

413

970

940

905

870

825

775

730

675

570

505

Yellow

2.0

385

910

880

845

810

770

725

675

600

535

475

Red

1.5

397

725

695

665

635

595

555

510

460

390

340

401712

SIDE/BOTTOM

Black

3.0

380

1365

1310

1255

1200

1140

1080

1015

950

860

795

Yellow

2.5

418

1245

1200

1150

1100

1045

990

930

855

790

730

Orange

2.5

366

1050

1025

985

950

915

870

820

760

705

655

Blue

2.0

435

980

955

935

905

870

830

780

725

675

625

Red

1.5

437

720

705

690

675

655

625

590

555

525

485

601412

SIDE/BOTTOM

Black

3.0

385

1215

1205

1205

1195

1155

1100

1045

975

910

805

Blue

2.5

370

980

985

980

955

925

880

835

780

695

585

Yellow

2.0

425

910

920

905

880

850

815

765

695

630

545

Red 

3

1.5

430

750

730

705

680

645

605

555

490

435

370

601716

SIDE/BOTTOM

Black

4.0

376

1600

1545

1505

1475

1505

1445

1400

1330

1235

1140

Yellow

3.5

377

1380

1340

1335

1330

1320

1285

1225

1155

1085

1000

Blue 

3

3.0

387

1190

1185

1195

1195

1160

1125

1075

1015

950

885

Red 

3

2.5

394

1030

1025

1030

1010

985

940

905

855

805

735

801716

SIDE/BOTTOM

Black

4.0

408

1800

1770

1735

1685

1630

1570

1495

1415

1330

1230

Yellow

3.5

386

1445

1430

1410

1385

1350

1305

1255

1195

1120

1045

Orange

3.0

390

1250

1240

1225

1200

1170

1130

1090

1040

975

910

Blue

2.5

404

1090

1080

1060

1035

1010

970

930

885

835

765

Red 

3

2.0

390

880

860

835

810

780

750

710

665

615

560

802120

BOTTOM or

TWO

SIDES 

4,5

Black

5.0

377

2225

2160

2070

1980

1885

1790

1690

1575

1460

1345

Yellow

4.0

386

1690

1665

1640

1595

1545

1485

1410

1330

1235

1135

Orange

3.5

397

1485

1470

1455

1430

1390

1340

1280

1205

1120

1035

Blue 

3

2.5

426

1120

1110

1100

1090

1065

1035

990

935

870

805

Red 

3

2.0

433

940

920

910

890

865

830

790

745

690

625

1002116

SIDE/BOTTOM

Black

4.0

373

1715

1660

1610

1555

1490

1420

1340

1245

1150

1065

Yellow 

3

3.5

379

1535

1480

1435

1380

1325

1260

1180

1095

1010

910

Blue 

3

3.0

367

1300

1255

1205

1160

1100

1035

970

905

810

730

Red 

3

2.0

445

1110

1055

1005

955

890

835

770

690

610

535

1002120

BOTTOM or

TWO

SIDES 

4,5

Black

5.0

394

2270

2205

2130

2055

1970

1880

1780

1670

1555

1425

Yellow

5.0

367

2090

2040

1980

1910

1835

1755

1670

1570

1460

1340

Blue

4.0

416

1850

1815

1775

1725

1665

1600

1525

1435

1335

1225

Red

3.5

421

1580

1550

1540

1515

1475

1420

1355

1280

1190

1100

1202420

BOTTOM or

TWO

SIDES 

4,5

Black

5.0

410

2385

2310

2230

2150

2050

1920

1780

1650

1540

1415

Yellow

5.0

369

2130

2070

2010

1940

1845

1740

1630

1525

1420

1305

Blue

4.0

416

1875

1840

1795

1735

1665

1580

1495

1410

1310

1205

Red 

3

3.5

414

1610

1585

1555

1515

1450

1395

1325

1250

1160

1080

NOTES:
1. A filter is required for each return

air inlet. Airflow performance includes a 3/4 in. (19 mm) washable filter media such as contained in factory

      authorized accessory filter rack. See accessory list. To determine airflow performance without this filter, assume an additional 0.1 in. W.C. 

     available external static pressure.

2. ADJUST THE BLOWER SPEED TAPS AS NECESSARY FOR THE PROPER AIR TEMPERATURE RISE FOR EACH INSTALLATION.

3. Shaded areas indicate that this airflow range is BELOW THE RANGE ALLOWED FOR HEATING OPERATION.   THESE AIRFLOW RANGES

     MAY ONLY BE USED FOR COOLING.
4. Airflows over 1800 CFM require bottom return, two

side return, or bottom and side return. A minimum filter size of 20” x 25” is required.

5. For upflow applications, air entering from one side into both the side of the furnace and a return air base counts as a side and bottom return.
6. All airflows that are shown in BOLD exceed 0.58 Watts per CFM at the given external static pressure.

Summary of Contents for N9MSB

Page 1: ...ls The signal word WARNING is used throughout this manual in the following manner Safety alert symbol When you see this symbol on the unit and in instructions or manuals be alert to the potential for personal injury TABLE OF CONTENTS START UP CHECK SHEET FOR PSC MOTOR 3 START UP ADJUSTMENT AND SAFETY CHECK 4 PRIME CONDENSATE TRAP WITH WATER 4 PURGE GAS LINES 4 ADJUST TEMPERATURE RISE 10 ADJUST BLO...

Page 2: ...death WARNING signifies hazards which could result in personal injury or death CAUTION is used to identify unsafe practices which may result in minor personal injury or product and property damage NOTE is used to highlight suggestions which will result in enhanced installation reliability or operation WARNING PERSONAL INJURY AND OR PROPERTY DAMAGE HAZARD Failure to carefully read and follow this w...

Page 3: ...eam of Furnace Drip Leg Gas Valve turned ON Type of Gas Natural Propane Filter Type and Size Check in box the Blower OFF Delay Jumper Heating Position for Fan Time OFF Setting 1 and 2 2 and 3 3 and 4 5 and 6 90 120 150 180 Calculated Input BTU Rate See Checks and Adjustments Section Heating Check Measured Line Pressure During Heat Measured Manifold Pressure Heat Temperature of Supply Air Heat Temp...

Page 4: ...ON Before operating furnace check flame rollout manual reset switch for continuity If necessary press button to reset switch EAC 115vac terminal is energized whenever blower operates HUM 24vac terminal is only energized the draft inducer is energized in heating Prime Condensate Trap with Water CARBON MONOXIDE POISONING HAZARD Failure to follow these warnings could result in personal injury or deat...

Page 5: ... gas heating values Refer to the instructions provided in the factory specified Propane conversion kit for instructions for setting gas manifold pressures for Propane applications In the USA the input rating for altitudes above 2000 ft 610 M must be reduced by 2 percent for each 1000 ft 305 M above sea level refer to Table 1 The natural gas manifold pressures in Table 3 adjust for BOTH altitude an...

Page 6: ...ometer to the inlet pressure tap on gas valve 4 Turn on furnace power supply 5 Turn gas supply manual shutoff valve to ON position 6 Turn furnace gas valve switch to ON position 7 Jumper R and W thermostat connections at the furnace control board 8 When main burners ignite confirm inlet gas pressure is between 4 5 in w c 1125 Pa and 13 6 in w c 3388 Pa 9 Remove jumper across thermostat connections...

Page 7: ...lution and note reading The 2 or 5 cubic feet dial provides a more accurate measurement of gas flow e Refer to Table 2 for cubic ft of gas per hr f Multiply gas rate cu ft hr by heating value Btuh cu ft to obtain input If clocked rate does not match required input from Step 1 increase manifold pressure to increase input or decrease manifold pressure to decrease input Repeat steps b through e until...

Page 8: ...FORMER 24 VAC CONNECTIONS P2 HOT SURFACE IGNITOR HSI INDUCER MOTOR IND CONNECTOR 115 VAC L1 LINE VOLTAGE CONNECTION SPARE1 COM BLUE 115 VAC L2 NEUTRAL CONNECTIONS 24 V THERMOSTAT TERMINALS HUMIDIFIER TERMINAL 24 VAC 0 5 AMP MAX 3 AMP FUSE LED OPERATION DIAGNOSTIC LIGHT 24VAC RED BLOWER SPEED SELECTION TERMINALS HUM XFMR HUMIDIFIER TERMINAL 115 VAC 120 180 90 150 SPARE2 J2 JUMPER J2 HUM 24VAC BLW S...

Page 9: ... 300 21 171 343 857 62 58 116 290 22 164 327 818 64 56 112 281 23 157 313 783 66 54 109 273 24 150 300 750 68 53 106 265 25 144 288 720 70 51 103 257 26 138 277 692 72 50 100 250 27 133 267 667 74 48 97 243 28 129 257 643 76 47 95 237 29 124 248 621 78 46 92 231 30 120 240 600 80 45 90 225 31 116 232 581 82 44 88 220 32 113 225 563 84 43 86 214 33 109 218 545 86 42 84 209 34 106 212 529 88 41 82 2...

Page 10: ...3 42 3 4 42 3 5 42 3 6 3001 800 43 3 8 42 3 2 42 3 3 42 3 4 915 825 43 3 6 43 3 7 43 3 8 42 3 2 850 44 3 8 43 3 5 43 3 6 43 3 7 875 44 3 6 44 3 7 43 3 4 43 3 5 4000 900 44 3 4 44 3 5 44 3 7 44 3 8 1219 925 44 3 2 44 3 4 44 3 5 44 3 6 950 44 3 1 44 3 2 44 3 3 44 3 4 750 42 3 3 42 3 4 42 3 5 42 3 6 4001 775 43 3 7 43 3 8 42 3 3 42 3 4 1220 800 43 3 5 43 3 6 43 3 7 43 3 8 825 44 3 8 43 3 4 43 3 5 43 ...

Page 11: ...ading Leaving blower door off will result in incorrect temperature measurements due to possible changes in duct static pressure and airflow FURNACE DAMAGE HAZARD Failure to follow this caution may result in S Overheating the heat exchangers or condensing flue gases in heat exchanger areas not designed for condensate S Shortened furnace life S Component damage Temperature rise must be within limits...

Page 12: ...se terminals R and W The thermostat anticipator should NOT be in the circuit while measuring current 1 Remove thermostat from sub base or from wall 2 Connect an amp meter across the R and W sub base terminals or R and W wires at wall 3 Record amp draw across terminals when furnace is in low heat and after blower starts 4 Set heat anticipator on thermostat per thermostat instructions and install on...

Page 13: ... Verify that there are no unsealed openings in the blower shelf or casing 5 Verify that the blower lower door in upflow position and control Main or upper door in upflow position doors are properly installed 6 Verify that the Status LED heartbeat bright dim If not check that the power supply is energized and that the blower door is secure See Figure 14 to interpret diagnostic codes 7 Cycle test fu...

Page 14: ...1665 1640 1595 1545 1485 1410 1330 1235 1135 Orange 3 5 397 1485 1470 1455 1430 1390 1340 1280 1205 1120 1035 Blue 3 2 5 426 1120 1110 1100 1090 1065 1035 990 935 870 805 Red 3 2 0 433 940 920 910 890 865 830 790 745 690 625 1002116 SIDE BOTTOM Black 4 0 373 1715 1660 1610 1555 1490 1420 1340 1245 1150 1065 Yellow 3 3 5 379 1535 1480 1435 1380 1325 1260 1180 1095 1010 910 Blue 3 3 0 367 1300 1255 ...

Page 15: ...blower is located below the combustion and controls section of the furnace and conditioned air is discharged upward Since this furnace can be installed in any of the 4 positions shown in Figure 6 you must revise your orientation to component location accordingly Figure 6 Multipoise Orientations A93041 Electrical Controls and Wiring Pressure Switches Each pressure switch is labeled with the referen...

Page 16: ... are active The stored status codes will NOT be erased from the control memory when 115 or 24 V power is interrupted See the Service Label See Figure 14 for more information The most recent fault code may be retrieved as follows 1 Leave 115 V power connected to furnace 2 Observe the status LED through the blower door the lower door on upflow applications indicator Refer to the Service Label See Fi...

Page 17: ...ace with filter or filtration device access doors removed WARNING CUT HAZARD Failure to follow this caution may result in personal injury Sheet metal parts may have sharp edges or burrs Use care and wear appropriate protective clothing safety glasses and gloves when handling parts and servicing furnaces CAUTION The minimum maintenance on this furnace is as follows 1 Check and clean air filter each...

Page 18: ...teps a through e g Tighten all clamps 15 lb in See Figure 8 for steps 5 through 14 5 Remove screws securing blower assembly to blower shelf and slide blower assembly out of furnace Detach ground wire and disconnect blower motor harness plugs from blower motor NOTE Blower wheel is fragile Use care 6 Clean blower wheel and motor by using a vacuum with soft brush attachment Be careful not to disturb ...

Page 19: ...supply and cycle furnace through one complete heating cycle Verify the furnace temperature rise as shown in Adjustments Section Adjust temperature rise as shown in Adjustments Section Cleaning Burners and Flame Sensor The following items must be performed by a qualified service technician If the burners develop an accumulation of light dirt or dust they may be cleaned by using the following proced...

Page 20: ... Figure 10 and Figure 11 Figure 10 Igniter Position Top View A11405 2 1 2 in 64 4 1 1 4 in 31 8 Figure 11 Igniter Position Side View L12F041 2ïin 2 5 mm 3 8ïin 3 16ïin 0 8 ï1 5 mm 50 mm 9 6 mm 4 6 mm 1 10ïin 1 32 ï 1 16ïin 9 Attach the wires to the roll out switches 10 Align the burner assembly with the openings in the primary cell inlet panel and attach the burner assembly to the cell panel 11 Co...

Page 21: ...rt on collect box and the trap with a small wire Shake any water out of the tube 13 Reconnect relief tube to trap and collector box ports Cleaning Condensate Drain and Trap NOTE If the condensate trap is removed a new gasket between the trap and collector box is required Verify a condensate trap gasket is included in the service kit or obtain one from your local distributor 1 Disconnect power at e...

Page 22: ...y restrict flow of combustion products 8 Reverse items 6 through 1 for reassembly 9 Refer to furnace wiring diagram and reconnect wires to flame rollout switch gas valve igniter and flame sensor 10 Turn on gas and electrical supplies to furnace 11 Check furnace operation through two complete heat operating cycles Look at burners Burner flames should be clear blue almost transparent See Figure 13 F...

Page 23: ...the funnel tube Antifreeze should run through the collector box overfill condensate trap and flow to an open drain 8 Replace the rubber plug in the port on the collector box 9 Remove the middle unused rubber plug from the port on the collector box opposite the condensate trap See Figure 1 10 Repeat Steps 5 through 8 11 If a condensate pump is used check with pump manufacturer to verify pump is saf...

Page 24: ...SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace N9MSB Specifications subject to change without notice 24 440 04 4413 03 Figure 14 Service Label 338310 2 Rev F ...

Page 25: ...SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace N9MSB Specifications subject to change without notice 440 04 4413 03 25 Figure 15 Wiring Diagram 339241 2 Rev A ...

Page 26: ...equence Gas valve and humidifier will not be turned on Inducer motor will start and remain on until the end of the blower test then off The following components are on for 10 15 seconds each individually hot surface igniter blower speeds FAN if present HEAT COOL Was there a previous status code Go to section below for the flashed status code Does the control respond to W Y1 Y Y2 and G 24V thermost...

Page 27: ...ponent test Does the igniter glow orange white by the end of the 15 second warm up period Unplug igniter harness from control and repeat component test Check for 115V between connector P2 HSI and NEUTRAL L2 on the control Was 115V present for the 15 second period Check connections and retry If current is near typical value 4 0 6 0 A DC nominal and burners will not stay on replace control Clean fla...

Page 28: ...nds after the gas valve GV is energized Simultaneously the electronic air cleaner terminal EAC is energized and remains energized as long as the blower motor BLWM is energized f Heat Off Delay When the thermostat is satisfied the R to W circuit is opened de energizing the gas valve GV stopping gas flow to the burners and de energizing the humidifier terminal HUM 24 VAC The inducer motor IDM will r...

Page 29: ...ector box Condensate trap Condensate trap elbow Gaskets WARNING FIRE EXPLOSION ELECTRICAL SHOCK AND CARBON MONOXIDE POISONING HAZARD Failure to follow this warning could result in dangerous operation personal injury death or property damage Improper installation adjustment alteration service maintenance or use can cause carbon monoxide poisoning explosion fire electrical shock or other conditions ...

Page 30: ...X ECM S Single stage T Two stage FEATURE B Base AFUE Efficiency E Extra AFUE Efficiency C Communicating D Dual Certified 2 pipe or 1 pipe R 2 pipe only S Single stage T Two stage N Standard L Low Nox FEATURE 040 40 000 BTU hr 060 60 000 BTU hr 080 80 000 BTU hr 100 100 000 BTU hr 120 120 000 BTU hr INPUT HEAT 14 14 3 16 17 17 1 2 21 21 24 24 1 2 CABINET WIDTH 10 1000 CFM max 14 1400 CFM max 16 160...

Reviews: