manualshive.com logo in svg

A.O. Smith BTH 120-250(A), Инструкция по установке и эксплуатации, Страница: 15 / 32

Поделиться
Скачать
A.O. Smith BTH 120-250(A) Скачать руководство пользователя страница 15

15

OPERATION

SEQUENCE OF OPERATION

Typical Control/Appliance Operating Sequence

1. When the control is initially powered, it enters a test mode and will

display the current software revision (example "104") for approximately
2 seconds, then "88.8" and all the LED's will illuminate for approximately
2 seconds. At this point, the control is in the idle mode and will display
the actual tank temperature.

2. If the control determines the actual water temperature inside the tank is

below the programmed temperature setpoint less one half the differential,
a call for heat is activated.

3. The control then performs selected system diagnostic checks. This

includes confirming the proper state of the air switch, ignitor, gas valve,
flame sense rod, and ECO limit device.

4. If all checks are successfully passed, the combustion blower is energized

for the pre-purge cycle.

5. When the pre-purge cycle is complete, power is applied to the ignitor

element for the ignitor warm-up period (blower should continue to run).

6. During the ignitor warm-up period, the control will sense ignitor current.

If ignitor current is within the specified range, the controller will energize
(open) the gas valve at the end of the ignitor warm-up period, allowing
gas to enter the burner chamber. If ignitor current is not within the
specified range, the control will not energize the gas valve, and the
control will return to Step 2 of the process. (See section below: Appliance
Ignition Failure).

7. After energizing the gas valve, the control will keep the ignitor on for a

short predetermined time period, then remove power to the ignitor.

8. After an additional 1 second, the control will monitor the flame sense

probe to confirm a flame is present. If a flame is not verified within this
time period, the controller will immediately de-energize (close) the gas
valve, and return to step two of the process. (See section below:
Appliance Ignition Failure).

9. If a flame is confirmed, the control will enter the heating mode where it

will continue heating the tank water until the setpoint temperature plus
one half the differential is reached. At this point, the gas valve is closed
and the control enters the post-purge cycle.

10.The combustion blower will run for the duration of the post purge cycle

to purge the system of all combustion  gases. When the post purge
cycle is complete, the blower is de-energized and will coast to a stop.

11. The control will now enter the idle state while continuing to monitor the

internal tank water temperature and the internal state of the controller. If
the temperature drops below the setpoint value less one half the
differential, the control will automatically return to Step 2 and repeat the
entire operating cycle.

SELF DIAGNOSTIC CONTROLLER

A green LED is mounted on the Main Control Board to indicate line voltage
polarity is properly connected. The green LED is mounted next to connector
CN1 (Line input connection). When 120 VAC input power is properly
connected to the Main Control Board, the green LED will illuminate. If an
error is made when connecting 120 VAC input power, this LED will not light.
Improperly connecting the input power may result in a false sensor failure.

The 24 VAC circuitry is protected with a 3 amp auto fuse. If the fuse opens,
the LED display and discrete LED's on the Display Board assembly will not
illuminate. The recommended fuse replacement part is Littlefuse p/n 257003
automotive fuse. Repeated failure of the fuse is an indication of possible
damage to the Main Control Board. If repeated fuse failure occurs, return
the Control Board for service.

Under normal operating conditions, should the ignitor current fall out of
specification or the gas fail to light at the burner during the first trial for
ignition, the control will perform two (2) more ignition trials prior to entering
a lockout state. Note that each subsequent ignition trial will not occur
immediately. After a failed trial for ignition, the controller will remove all
power from the blower, gas valve, and ignitor and return to the call for heat
state. If a call for heat is activated, the controller will energize the combustion
blower for the pre-purge cycle, and again activate the ignitor to complete its
warm-up period. After the warm-up period, the gas valve is opened, ignitor
power removed, and the control will again check for flame.

If ignition is sensed during any one of these trials, normal operation will
resume. If ignitor current should fall out of specification or flame is not
sensed after the third ignition trial, the control will automatically enter a
lockout state ("Loc" displayed on the Display Board) and the ignitor or gas
valve LED on the Display Board will flash. The lockout state is manually
reset by momentarily pressing the push-button on the Display Board. If a
manual reset does not occur within a one hour time period, the controller
will automatically reset the lockout condition and provided the call for heat
still exists, will attempt another ignition sequence.

FIGURE 18

FIGURE 17

14. Tubing-Pressure
15. Tubing-Pressure
17. Switch-On/Off
18. Low Gas Pressure Switch

(BTH 120 and 250 Only).

19. Bocked Inlet Switch
20. Wire Assembly-Air

Flow Switch

ITEM DESCRIPTION

 

 1.

Transformer

  2. Control Board & Cable Ass'y
  3. E.C.O./Temperature  Probe
  4. Blower Proving Air Switch
  5. Low  Voltage Cable Assembly
  6. Line  Voltage  Cable Assembly
  7. Blower/Motor  Assembly
  8. Igniter  Assembly
10. Control Display Board
11.

Blocked Outlet Exhaust Switch

12. Lower Temperature Probe
13. Wire Assembly-Gas Pressure

Switch

Содержание BTH 120-250(A)

Страница 1: ...FORE INSTALLING AND USING THIS APPLIANCE INSTALLATION OPERATION SERVICE MAINTENANCE LIMITED WARRANTY WARNING If the information in these instructions is not followed exactly a fire or explosion may result causing property damage personal injury or death Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance WHAT TO DO IF YOU SMELL GAS Do n...

Страница 2: ... ProtectionAssociation 1 Batterymarch Park Quincy MA02269 FOREWORD CYCLONE XHE BTH 120 250 ROUGH IN DIMENSIONS TEMPERATURE RISE DEGREES C LITERS PER HOUR Approx Input Liter Model kW Capacity 17 C 22 C 28 C 33 C 39 C 44 C 50 C 56 C 61 C 67 C 72 C 78 C BTH 120 37 Nat 227 1798 1348 1079 898 768 674 598 538 488 450 416 386 BTH 120 35 L P 227 1726 1295 1037 863 738 647 575 519 469 432 397 371 BTH 150 4...

Страница 3: ...tion WATER TEMPERATURE CONTROL TABLE OF CONTENTS ROUGH INDIMENSIONS 2 FOREWORD 2 FEATURES 3 4 Water Temperature Control 3 High Limit Switch E C O 4 Dishwashing Machine Requirement 4 Circulating Pump 4 INSTALLATIONINSTRUCTIONS 4 13 Required Ability 4 Insulation Blankets 4 5 Locating The Heater 5 Clearances 5 Hard Water 6 Air Requirements 6 Mechanical Exhausting of Room Air 6 Unconfined Space 6 Conf...

Страница 4: ...n Foundation requirements are designed to operate with water flow pressures between 15 and 25 pounds per square inch 103 Kpa and 173 Kpa Flow pressures above 25 pounds per square inch 173 Kpa or below 15 pounds per square inch 103 Kpa will result in improperly sanitized dishes Where pressures are high a water pressure reducing or flow regulating control valve should be used in the 180 F 82 C line ...

Страница 5: ...quality water pressure and the environment in which the water heater is installed Water heaters are sometimes installed in locations where leakage may result in property damage even with the use of a drain pan piped to a drain However unanticipated damage can be reduced or prevented by a leak detector or water shut off device used in conjunction with a piped drain pan These devices are available f...

Страница 6: ...UNLESS RUBBER ISOLATION PIPE HANGERSARE USED THIS PREVENTSANY VIBRATIONS FROM BEING ALCOVE HARDWATER Where hard water conditions exist water softening or the threshold type of water treatment is recommended This will protect the dishwashers coffee urns water heaters water piping and other equipment See MAINTENANCE section for details of tank cleanout procedure AIR REQUIREMENTS KEEP APPLIANCE AREA ...

Страница 7: ...RMINATE EXHAUST OVER PUBLIC AREA WHERE CONDENSATE OR VAPOR CAN CAUSE NUISANCE OR HAZARD ON DIRECT VENT INSTALLATIONS EXHAUST VENT HOOD MUST BE LOCATED 1 30 5cm MINIMUM FROM ANY OPENING IN BUILDING ON DIRECT VENT INSTALLATIONS EXHAUST VENT HOOD MUST BE LOCATED 4 122cm MINIMUM FROM ANY OPENING IN BUILDING ...

Страница 8: ... the vent system layout so that proper clearances are maintained from plumbing and wiring Vent pipes serving power vented appliances are classified by building codes as vent connectors Required clearances from combustible materials must be provided in accordance with information in this manual under LOCATION OF HEATER and CLEARANCES and with National Fuel Gas Code and local Codes IMPORTANT Plan th...

Страница 9: ... wall Align the holes by drilling a hole through the center of the template from the inside through to the outside The template can now be positioned on the outside wall using the drilled holes as a centering point for the template 3 A MASONRY SIDE WALLS Chisel an opening approximately 1 2 1 3 cm larger than the marked circle B WOODEN SIDE WALLS Drill a pilot hole approximately one quarter inch ou...

Страница 10: ...tions should be sealed with a plumbing roof boot or equivalent flashing 3 The intake vent termination and the exhaust vent termination must penetrate the same side of roof 4 The center line of the intake vent termination and the center line of the exhaust vent termination must be no closer than 24 61cm 5 The intake vent terminal and the exhaust vent terminal must be oriented facing downward and th...

Страница 11: ...90 elbows with the 4 inch venting is six 6 on the intake and six 6 on the exhaust A 90 elbow is equal to five 5 equivalent feet 1 5m of pipe One 1 90 elbow is equal to two 2 45 elbows Any venting configuration using less than 50 equivalent feet should use 3 inch venting See Table 2 The 3 inch venting terminals provided must be used with the 4 inch venting by adding 4x3 reducing couplings at the ve...

Страница 12: ...h is considered normal for low pressure systems Note that fittings such as elbows and tees will add to the pipe pressure drop CAUTION DO NOT USE FLEXIBLE GAS PIPING TABLE 3 MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS PER HOUR Based upon a Pressure Drop of 0 5 inch Water Column and 0 6 Specific Gravity Gas and max gas pressure of 0 5 psig WARNING THE HEATER IS NOT INTENDED FOR OPERATIONAT HIGHER ...

Страница 13: ...ter is too small ask the gas company to install a larger meter having adequate capacity GAS PRESSURE REGULATION Main line gas pressure to the water heater should be between a maximum 14 0 3 45Kpa W C and a minimum as shown in Table 4 that is for Natural Gas 5 0 1 25Kpa W C for BTH 120 250 or 4 5 1 12Kpa W C for BTH 150 199 or for L P Gas 11 0 2 74Kpa W C The inlet gas pressure must not exceed the ...

Страница 14: ...TER TANK IS FILLED WITH WATER NOTE This controller is Polarity Sensitive If the Hot and Neutral Supply Voltage is reversed the controller will not sense flame Verify polarity before connecting the unit WATER LINE CONNECTIONS This manual provides detailed installation diagrams see back section of this manual for typical methods of application for the water heaters The water heater may be installed ...

Страница 15: ...y return to Step 2 and repeat the entire operating cycle SELF DIAGNOSTIC CONTROLLER A green LED is mounted on the Main Control Board to indicate line voltage polarity is properly connected The green LED is mounted next to connector CN1 Line input connection When 120 VAC input power is properly connected to the Main Control Board the green LED will illuminate If an error is made when connecting 120...

Страница 16: ... Clogged gas valve 6 Replace gas valve 7 Faulty gas valve 7 Replace gas valve 8 Defective control 8 Replace control 9 Burner improperly adjusted 9 Adjust burner 10 Dirty burner 10 Clean burner GAS VALVE LED FLASHING This condition results from a failure to establish burner ignition after three successive trials In such cases 1 Investigate the possible cause and remedy any observations 2 Momentaril...

Страница 17: ...ntrol problem 2 Water in tank above freezing 2 Temperature probe out of tolerance replace temp probe PossibleCause Remedy 1 Water in tank is low probe 1 Fill tank immersed in steam 2 Probe wiring shorted 2 Repair wiring 3 Defective probe 3 Replace probe PossibleCause Remedy 1 Temp Probe unplugged 1 Check connectors 2 Temp probe wiring damaged 2 Repair wiring 3 Water in tank too hot 3 Normal condit...

Страница 18: ...ect orifice PRIOR TO START UP REQUIRED ABILITY INSTALLATION OR SERVICE OFTHIS WATER HEATER REQUIRESABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE FIELD INVOLVED PLUMBING AIR SUPPLY VENTING GAS SUPPLY AND ELECTRICALWORKAREREQUIRED Before attempting start up thoroughly study and familiarize yourself with the exact sequence of operation and all other details on the specific heater being us...

Страница 19: ...19 FORYOUR SAFETYREAD BEFORE OPERATING WARNING If you do not follow these instructions exactly a fire or explosion may result causing property damage personal injury or loss of life ...

Страница 20: ...LATIONS WARNING BTH HEATERSARE CERTIFIED FOR USE WITHOUT MODIFICATION FOR ALTITUDES UP TO 6500 FEET INSTALLATIONSABOVE 6500 FEET MAY REQUIRE REPLACEMENT OF THE BURNER ORIFICE CALL THE TECHNICAL CENTER 800 527 1953 FOR REQUIREMENTS Some gas utility companies derate their gas for altitude making it unneccessary to install high altitude orifices Call the local gas or utlity company to verify BTU cont...

Страница 21: ...alve when finished flushing 4 Turn on the heater electrical disconnect switch DRAINING The heater must be drained if it is to be shut down and exposed to freezing temperatures Maintenance and service procedures may also require draining the heater 1 Turn off the heater electrical disconnect switch 2 Close the cold water inlet valve to heater 3 Open a nearby hot water faucet to vent the system 4 Op...

Страница 22: ...and a tank explosion In areas with poor water conditions it may be necessary to inspect the T P valve more often than every three years CAUTION BEFORE MANUALLY OPERATING THE VALVE MAKE SURE THAT A DRAIN LINE HAS BEEN ATTACHED TO THE VALVE TO DIRECT THE DISCHARGE TOAN OPEN DRAIN FAILURE TO TAKE THIS PRECAUTION COULD MEAN CONTACT WITH EXTREMELY HOT WATER PASSING OUT THE VALVE DURING THIS CHECKING OP...

Страница 23: ...OT WATER SUPPLIED TO FIXTURES PIPE TO OPEN DRAIN INSTALLINACCORDANCE WITH LOCAL CODES CAUTION IF BUILDING COLD WATER SUPPLY HAS A BACK FLOW PREVENTER CHECK VALVEORWATERMETERWITH CHECK VALVE PROVISIONS FOR THERMALEXPANSION OF WATER IN THE HOT WATER SYSTEM MUST BE PROVIDED NOTE CONNECT RETURN LINE FROM HOT WATER CIRCULATING LOOP IF USED TO COLD WATER INLET LINE PIPE TO OPEN DRAIN INSTALLINACCORDANCE...

Страница 24: ...DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATUREATFIXTURES SEEWATERTEMPERATURE CONTROL WARNING ON PAGE 4 IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT ADD AN ANTI SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES CAUTION IF BUILDING COLD WATER SUPPLY HAS A BACK FLOW PREVENTER CHECK VALVE OR WATER METERWITHCHECKVALVEPROVISIONSFORTHERMAL EXPANSION OF WATER ...

Страница 25: ...IT SPECIFICATIONS PAGE28 CAUTION IF BUILDING COLD WATER SUPPLY HAS A BACK FLOW PREVENTER CHECK VALVE OR WATER METER WITH CHECK VALVE PROVISIONS FOR THERMALEXPANSION OF WATER IN THE HOT WATER SYSTEM MUST BE PROVIDED DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE ATFIXTURES SEEWATERTEMPERATURECONTROLWARNINGONPAGE 4 IF HIGHER PREHEAT TEMPERATURESARE NECESSARY TO OBTAIN ADEQUATE BOOSTER...

Страница 26: ...ECTCIRCULATINGLINEOF180 F 82 C ORBOOSTEDWATER IF USED TO INLETWATER LINETO BOOSTER INSTALLINACCORDANCE WITH LOCALCODES TWO TEMPERATURE TWO HEATERS ONE PRE HEATER ONE BOOSTER HEATER WITH OR WITHOUT BUILDING RECIRCULATION DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE ATFIXTURES SEEWATERTEMPERATURECONTROLWARNINGONPAGE 4 IF HIGHER PREHEAT TEMPERATURESARE NECESSARY TO OBTAIN ADEQUATE BO...

Страница 27: ...TANK NOTE4 IFTEMPEREDWATERISRECIRCULATED RETURNLINESHOULD BE CONNECTEDATPOINTA DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE ATFIXTURES SEEWATERTEMPERATURECONTROLWARNINGONPAGE 5 IF HIGHER PREHEAT TEMPERATURESARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT ADD ANANTI SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES CAUTION IF BUILDING COLD WATER SUPPLY HAS A BACK FLOW PREVENTER CHECK ...

Страница 28: ...ter heating and storage potential of the system cannot be achieved Plus the units with the higher water flow may have a shortened life Unions shown in piping diagrams are not included in the manifold kits Dimensions shown are for minimum space occupied by the water heaters assemblies Space for the venting system and unit servicing must be added ...

Страница 29: ...o see if the water heater drain valve is tightly closed Also check the cleanout opening for leakage 2 The apparent leakage may be condensation which forms on cool surfaces of the heater and piping 3 If the outlet of the relief valve is leaking it may represent Excessive water pressure Excessive water temperature Faulty relief valve Excessive water pressure is the most common cause of relief valve ...

Страница 30: ...a W C or lower than the minimal gas supply pressure as shown in Table 4 that is for Natural Gas 5 0 1 25 kPa W C for BTH 120 250 or 4 5 1 1 kPa W C for BTH 150 199 or for L P Gas 11 0 2 74 kPa W C pressure Also the manifold pressure should rise during the three 3 second trial for ignition to the manifold pressure value for the individual unit listed in Table 4 that is for Natural Gas 4 0 1 kPa W C...

Страница 31: ... to unless an effective method of controlling thermal expansion is also installed at the heater s and operational at all times The relief valve installed on the heater is not an acceptable method 4 SERVICEAND REPAIR EXPENSES Under the limited warranty the warrantor will provide only a replacement water heater or part thereof The owner is responsible for all other costs Such costs may include but a...

Страница 32: ...32 A O SMITH WATER PRODUCTS COMPANY 5621 W 115TH STREET ALSIP ILLINOIS 60803 PHONE 1 800 433 2545 FAX 1 800 433 2515 www hotwater com E MAIL parts hotwater com ...

Отзывы:

Нет отзывов