Bryant 677C--A Check Burner Flame, Normal Operation, Airflow and Temperature Rise, Limit Switches

Page 15

REGULATOR

COVER SCREW

PLASTIC

ADJUSTMENT

SCREW

ON/OFF SWITCH

REGULATOR SPRING (PROPANE - WHITE) (NATURAL - SILVER)

 

GAS PRESSURE

 

REGULATOR

INLET

ADJUSTMENT

PRESSURE TAP

 

MANIFOLD

PRESSURE TAP

A07751

Fig. 13 - Single-Stage Gas Valve

If larger adjustments are required, change main burner orifices following the recommendations of national and local codes.

NOTE: All other appliances that use the same meter must be turned off when gas flow is measured at the meter.

Proceed as follows:

1.Turn off gas supply to unit.

2.Remove pipe plug on manifold (See Fig. 11) and connect manometer. Turn on gas supply to unit.

3.Record number of seconds for gas meter test dial to make one revolution.

4.Divide number of seconds in Step 3 into 3600 (number of seconds in one hr).

5.Multiply result of Step 4 by the number of cubic feet (cu ft) shown for one revolution of test dial to obtain cubic feet (cu ft) of gas flow per hour.

6.Multiply result of Step 5 by Btu heating value of gas to obtain total measured input in Btuh. Compare this value with heating input shown in Table 3 (Consult the local gas supplier if the heating value of gas is not known).

EXAMPLE: Assume that the size of test dial is 1 cu ft, one revolution takes 32 sec, and the heating value of the gas is 1050 Btu/ft3. Proceed as follows:

1.32 sec. to complete one revolution.

2.3600 ÷ 32 = 112.5.

3.112.5 x 1 =112.5 ft3 of gas flow/hr.

4.112.5 x 1050 = 118,125 Btuh input.

If the desired gas input is 115,000 Btuh, only a minor change in the manifold pressure is required.

Observe manifold pressure and proceed as follows to adjust gas input:

1.Remove regulator cover screw over plastic adjustment screw on gas valve (See Fig. 13).

2.Turn plastic adjustment screw clockwise to increase gas input, or turn plastic adjustment screw counterclockwise to decrease input (See Fig. 13). Manifold pressure must be between 3.2 and 3.8 IN. W.C.

!WARNING

FIRE AND UNIT DAMAGE HAZARD

Failure to follow this warning could result in personal injury or death and/or property damage.

Unsafe operation of the unit may result if manifold pressure is outside this range.

3.Replace regulator cover screw on gas valve (See Fig. 13).

4.Turn off gas supply to unit. Remove manometer from pressure tap and replace pipe plug on gas valve. (See Fig. 11.) Turn on gas to unit and check for leaks.

Measure Manifold Pressure (Propane Units)

Refer to propane kit installation instructions for properly checking gas input.

NOTE: For installations below 2,000 ft (610 m), refer to the unit rating plate for proper propane conversion kit. For installations above 2,000 ft (610 m), contact your distributor for proper propane conversion kit.

Check Burner Flame

With control access panel (see Fig. 19) removed, observe the unit heating operation. Watch the burner flames to see if they are light blue and soft in appearance, and that the flames are approximately the same for each burner. Propane will have blue flame (See Fig. 12). Refer to the Maintenance section for information on burner removal.

Normal Operation

An LED (light-emitting diode) indicator is provided on the integrated gas unit controller (IGC) to monitor operation. The IGC is located by removing the control access panel (see Fig. 19). During normal operation, the LED is continuously on (See Table 5 for error codes).

Airflow and Temperature Rise

The heating section for each size unit is designed and approved for heating operation within the temperature-rise range stamped on the unit rating plate.

Table 10 shows the approved temperature rise range for each heating input, and the air delivery cfm at various temperature rises for a given external static pressure. The heating operation airflow must produce a temperature rise that falls within the approved range.

Refer to Indoor Airflow and Airflow Adjustments section to adjust heating airflow when required.

Limit Switches

Normally closed limit switch (LS) completes the control circuit. Should the leaving-air temperature rise above the maximum allowable temperature, the limit switch opens and the control circuit “breaks.” Any interruption in the control circuit instantly closes the gas valve and stops gas flow to the burners and pilot. The blower motor continues to run until LS resets.

When the air temperature at the limit switch drops to the low-temperature setting of the limit switch, the switch closes and

677C-- -- A

15

Image 15
Contents Safety Considerations Table of ContentsIntroduction Receiving and Installation677C--A24-30 Unit Dimensions 677C--A36-60 Unit Dimensions CPRFCURB012A00 Unit SizeCPRFCURB010A00 CPRFCURB011A00Rig and Place Unit InspectionRigging/Lifting of Unit See Fig Carbon Monoxide Poisoning Hazard Install Flue HoodInstall Gas Piping Connect Condensate DrainInstall Duct Connections Configuring Units for Downflow Vertical DischargeFire or Explosion Hazard Furnace Section CompressorsRefrigerant Metering CFMPhysical Data Unit 677C--A Cont’d Maximum Gas Flow CapacityHeating Inputs Control Voltage Connections Install Electrical ConnectionsSpecial Procedures for 208-V Operation High-Voltage ConnectionsFIRE, EXPLOSION, Electrical Shock Hazard Balance Point Setting-Thermidistat or Hybrid ThermostatPRE-START-UP Transformer ProtectionUnit Sequence of Operation Start-up Heating and Make Adjust- mentsSTART-UP Check for Refrigerant LeaksUnit Damage Hazard Adjust Gas InputCheck Heating Control Check Gas InputNormal Operation Airflow and Temperature RiseLimit Switches Check Burner FlameIndoor Airflow and Airflow Adjustments Start-up Cooling and Make Adjust- mentsRollout Switch Checking and Adjusting Refrigerant ChargeColor Coding for Indoor Fan Motor Leads Two Cooling Fan Speeds Set-up Dehumidification feature usedGas Heating Fan Speed Set-up Continuous Fan OperationFilter Size CFM 677C--A Wet Coil Pressure DropRise Speed Color Range Unit Heating Motor Wire1505 1452 1413 1358 1323 1282 1234 1169 1130 25 55oF Heating 1962 1915 1880 1843 1794 1753 1711 1675 1628 35 65oF Heating 1962 1915 1880 1843 1794 1753 1711 1675 1628 30 60oF Heating 1887 1847 1783 1726 1677 1625 1578 1527 1432 30 60oF Heating 677C a 208/230-3-60 Wiring Diagram, Unit 677C--A Cooling Charging Table-Subcooling Indoor Blower and Motor MaintenanceCleaning the Blower Motor and Wheel Air FilterFlue Gas Passageways Limit SwitchInduced Draft combustion air Blower Assembly Burner IgnitionEXPLOSION, Personal Injury and Environmental Hazard Electrical Controls and WiringOutdoor Fan Refrigerant CircuitIndoor Airflow Pressure SwitchesLoss of Charge Switch Gas InputHigh-Pressure Switch Copeland Scroll Compressor Puron RefrigerantExplosion Hazard Servicing Systems on Roofs and with Synthetic materials Unit Operation and Safety HazardRefrigerant System Compressor OilTroubleshooting START-UP ChecklistPuronr R-410A Quick Reference Guide Symptom Cause Remedy Troubleshooting Guide Cooling or Heat Pump Heating ModeTroubleshooting Guide-Heating Troubleshooting Guide-LED Status CodesLED OFF III. START-UP Electrical Supply Voltage Compressor Amps TemperaturesRemove and Store in Job Files Preliminary Information Model no