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1183746-UIM-B-0215

16

Johnson Controls Unitary Products

Main Burner Operation

The control board keeps the main gas valve and induced draft motor
energized while continuously monitoring the call for heat, pressure
switch, and flame status.

If the call for heat (W) is removed, the control de-energizes the gas
valve, begins post purge and heat blower off delay.

If the pressure switch opens, the control de-energizes the gas valve
and begins pressure switch proving mode.

If flame is removed, the control de-energizes the gas valve within 2.0
seconds and counts the flame loss. If flame has been lost less than 5
times, the control attempts re-ignition after a 15 second inter-purge
period. If flame has been lost more than 5 times within the same call for
heat, the control board locks out flashing “8” on the LED. Post Purge

The control board runs the induced draft motor for a 15 second post-
purge period, and then de-energizes the inducer. If a call for heat
occurs during post-purge, the control finishes the postpurge, and imme-
diately begins the next ignition sequence.

Heat Blower Off Delay

After a heating sequence the control board de-energizes the indoor
blower motor after a delay time as selected by a movable shunt (60, 90,
120 or 180 seconds). Blower off timing begins when the thermostat is
satisfied and removes (W) the call for heat. The control returns to
standby when the blower off delay is complete.

If the thermostat call for heat returns before the blower off delay is com-
plete, the control begins an ignition sequence with prepurge while the
blower off delay continues.

Lockout

While in lockout, the control board keeps the main gas valve and
induced draft motor de-energized.

Lockouts due to failed ignition or flame losses may be reset by remov-
ing the call for heat (W) for more than 1 second, or by removing power
from the control for over 0.25 seconds. The control will automatically
reset lockout after 60 minutes.

Lockouts due to detected internal control faults will reset after 60 min-
utes or power interruption. Cooling operations are available during a
heating lockout.

High Temperature Limit Switch

Any time the high temperature limit switch is open less than 5 minutes
the control board will run the indoor blower motor on heat speed, run
the inducer, de-energize the gas valve, and flash “4” on the LED. When
the high temperature switch closes, the control will restart the ignition
sequence beginning with pre-purge.

If the limit switch has been open more than 5 minutes the control will
de-energize the inducer, continue to operate the indoor blower motor on
heat speed, and flash “11” on the LED

Rollout Switch

If the limit circuit is open for more than 15 minutes, the control board will
flash “5” on the LED. The blower output will be energized during an
open rollout condition.

If the rollout switch is reset, the control shall remain locked out until
power is removed or a call for heat (W) is removed.

Rollout switch lockout shall not reset automatically.

Power Interruptions

Power interruptions of any duration shall not cause lockout or any oper-
ation requiring manual intervention.

Flame present with Gas off

If flame is sensed for longer than 4.0 seconds during a period when the
gas valve should be closed, the control will enter lockout flashing “1” on
the LED. The control will energize the inducer blower while the flame is
sensed.

GAS VALVE FAULT

If the main valve output is sensed to be energized for more than 1 sec-
ond when commanded to be off, the control de-energizes the induced
draft motor (if flame is not present) to attempt to open the pressure
switch to de-energize the gas valve. If the main gas valve is still sensed
as energized after the inducer has been off for 10 seconds, the control
re-energizes the inducer to vent the unburned gas. The control enters a
hard lockout flashing "10" on the LED.

The only way to recover from a hard lockout is to remove and reapply
24VAC power to the control board.

Safety Controls

The control circuit includes the following safety controls:

1.

Limit Switch (LS) - This control is located inside the blower compart-
ment and protrudes into the heat exchanger compartment and is set
to open at the temperature indicated in the Temperature Controls
Table of the unit wiring diagram. It resets automatically. The limit
switch operates when a high temperature condition occurs, thus
shutting down the ignition control, closes the main gas valve and
energizes the blower.

2.

Pressure Switch (PS) - If the draft motor should fail, the pressure
switch prevents the ignition control and gas valve from being ener-
gized.

3.

Flame Sensor - The flame sensor is located on the left-most burner.
If an ignition control fails to detect a signal from the flame sensor
indicating the flame is properly ignited, then the main gas valve will
close.

4.

Rollout Switch (RS) - This switch is located on the burner assembly.
In the event of a sustained main burner flame rollout, the control will
close the main gas valve. The is a manual reset type switch.

NOTICE

The manual reset Rollout Switch (RS) must be reset before allowing
furnace operation.

Table 14: 

Ignition Control Board Flash Codes

Flash Code

Description

Normal Operation

Green Heartbeat

Standby mode

Amber Heartbeat

Call for furnace heat active

Operational Faults

Steady ON (any color) Control failure

Rapid Amber Flash

Low flame current <1.5 VDC at test pad

1 Red Flash

Flame sensed with gas valve off

2 Red Flashes

Pressure switch closed with inducer off

3 Red Flashes

Pressure switch open with inducer on

4 Red Flashes

Limit switch or rollout switch open

5 Red Flashes

Limit switch or rollout switch open >15 minutes

6 Red Flashes

Pressure switch cycle lockout

7 Red Flashes

Lockout due to failed ignition

8 Red Flashes

Lockout due to too many flame dropouts

10 Red Flashes

Gas valve fault

11 Red Flashes

Limit/Rollout switch open between 5 and 15 
minutes

Wiring Related Faults

9 Red Flashes

Incorrect low voltage polarity

4 Amber Flashes

Y thermostat demand without a G

Summary of Contents for PCG4 Series

Page 1: ...y gas piping electric power and duct connections are required at the point of installation The gas fired heaters have spark ignition The refrigerant system is fully charged with R 410A Refrigerant and is tested and factory sealed SECTION II SAFETY This is a safety alert symbol When you see this symbol on labels or in manuals be alert to the potential for personal injury Understand and pay particul...

Page 2: ...ce or additional information consult a qualified installer service agency or the gas supplier CAUTION This system uses R 410A Refrigerant which operates at higher pres sures than R 22 No other refrigerant may be used in this system Gage sets hoses refrigerant containers and recovery systems must be designed to handle R 410A If you are unsure consult the equip ment manufacturer Failure to use R 410...

Page 3: ... unit to meet local codes they are to be installed at the dealer s and or customer s expense Size of unit for proposed installation should be based on heat loss heat gain calculation made according to the methods of Air Conditioning Contractors of America ACCA This furnace is not to be used for temporary heating of buildings or structures under construction FIGURE 1 Component Location FAN MOTOR CO...

Page 4: ...h a forklift Slotted openings in the base rails are provided for this purpose WARNING Excessive exposure of this furnace to contaminated combustion air may result in equipment damage or personal injury Typical contami nates include permanent wave solution chlorinated waxes and cleaners chlorine based swimming pool chemicals water softening chemicals carbon tetrachloride Halogen type refrigerants c...

Page 5: ...and recirculate Direction Distance in Direction Distance in Top3 3 Units must be installed outdoors Over hanging structure or shrubs should not obstruct condenser air discharge outlet 48 Power Entry Right Side 42 Side Opposite Ducts 36 Left Side 36 Duct Panel 12 Bottom4 4 Units may be installed on combustible floors made from class A B or C roof covering materials 1 HIGH VOLTAGE CONNECTION 7 8 HIG...

Page 6: ...y the blower decreasing your units efficiency and increasing operating costs and wear and tear on the unit and controls Filters should be checked monthly this is especially important since this unit is used for both heating and cooling CONDENSATE DRAIN A condensate trap must be installed in the condensate drain The plumbing must conform to local codes DO NOT use Teflon tape or Pipe thread compound...

Page 7: ...h unit must be wired with a separate branch circuit fed directly from the main distribution panel and properly fused Refer to Figures 7 and 8 for typical field wiring and to the appropriate unit wiring diagram for control circuit and power wiring information FIGURE 6 Typical Field Control Wiring Diagram For Gas Heat AC Models FIGURE 7 Typical Field Power Wiring Diagram THERMOSTAT NOTE Heat Anticip...

Page 8: ...Operating WT lbs 359 366 379 386 415 422 426 442 446 495 503 508 522 530 535 Compressors Type Recip Recip Recip Scroll Scroll Scroll Condenser Coil Data Face area Sq Ft 15 1 17 0 15 1 17 0 23 8 26 0 Rows 1 1 2 2 2 2 Fins per inch 22 22 22 22 22 22 Tube diameter 3 8 3 8 3 8 3 8 3 8 3 8 Circuitry Type Interlaced Interlaced Interlaced Interlaced Interlaced Interlaced Evaporator Coil Data Face area Sq...

Page 9: ... on the outside of the pipe and blowing out the loose dirt and scale Before initial start up be sure that all of the gas lines external to the unit have been purged of air CAUTION This system uses R 410A Refrigerant which operates at higher pres sures than R 22 No other refrigerant may be used in this system CAUTION Do not leave the system open to the atmosphere Unit damage could occur due to mois...

Page 10: ...y unauthorized human contact around this area during the heating cycle Flue hood surfaces and the immediate area reach high temperatures during the heating cycle New Graphic to be added later AIR INTAKE HOOD AIR INTAKE SCREEN EXHAUST HOOD A0284 001 Table 9 Natural Gas Application Data Available On Models Input MBH 1 High Fire 1 Heating capacity valid for elevations up to 2000 feet above sea level ...

Page 11: ...995 942 889 834 Medium 3 1259 1209 1166 1126 1084 1032 980 928 Medium High 4 1314 1271 1229 1186 1144 1097 1049 998 High 5 1506 1471 1403 1389 1345 1305 1262 1216 36075 Low 1 1225 1174 1131 1090 1046 993 941 888 Low Medium 2 1259 1209 1166 1126 1084 1032 980 928 Medium 3 1314 1271 1229 1186 1144 1097 1049 998 Medium High 4 1348 1306 1259 1222 1179 1133 1086 1036 High 5 1506 1471 1403 1389 1345 130...

Page 12: ...1413 Medium 3 1922 1863 1804 1754 1724 1658 1612 1559 Medium High 4 2001 1952 1890 1839 1820 1742 1696 1651 High 5 2146 2085 2025 1960 1872 1862 1798 1735 60065 Low 1 1073 1043 1009 988 963 941 917 892 Low Medium 2 1329 1292 1250 1223 1192 1165 1136 1105 Medium 3 2054 1998 1934 1890 1843 1801 1757 1710 Medium High 4 2195 2144 2098 2049 2003 1955 1883 1868 High 5 2445 2388 2306 2293 2235 2178 2129 ...

Page 13: ... 863 Medium 3 1262 1223 1181 1137 1091 1044 994 952 Medium High 4 1324 1282 1245 1202 1161 1112 1067 1018 High 5 1517 1475 1447 1400 1357 1318 1275 1232 36075 Low 1 1231 1186 1146 1103 1069 1030 977 912 Low Medium 2 1270 1225 1189 1140 1098 1046 1008 960 Medium 3 1317 1286 1245 1198 1151 1110 1064 1024 Medium High 4 1358 1317 1275 1238 1197 1148 1105 1057 High 5 1517 1475 1447 1400 1357 1318 1275 ...

Page 14: ...1419 Medium 3 1912 1875 1805 1787 1750 1713 1672 1636 Medium High 4 2105 2014 2006 1931 1898 1845 1793 1739 High 5 2131 2058 1998 1949 1892 1840 1788 1728 60065 Low 1 1026 999 989 950 907 907 886 862 Low Medium 2 1263 1230 1192 1165 1167 1101 1099 1071 Medium 3 1987 1933 1861 1817 1820 1715 1725 1651 Medium High 4 2114 2050 2047 1974 1899 1889 1920 1866 High 5 2369 2308 2249 2183 2126 2088 2034 19...

Page 15: ...on trial If the call for heat is removed during an ignition trial period the control immediately de energizes spark and gas The control runs the inducer motor through a post purge period before de energizing If the pressure switch opens during an ignition trial period the control immediately de energizes spark and gas The control begins pressure switch proving before an inter purge and reignition ...

Page 16: ...ved or a call for heat W is removed Rollout switch lockout shall not reset automatically Power Interruptions Power interruptions of any duration shall not cause lockout or any oper ation requiring manual intervention Flame present with Gas off If flame is sensed for longer than 4 0 seconds during a period when the gas valve should be closed the control will enter lockout flashing 1 on the LED The ...

Page 17: ...our service technician or gas supplier To Turn Off Gas To Unit 1 Set the thermostat to the OFF position 2 Turn off all electric power to the appliance if service is to be per formed 3 Remove the control access panel 4 Turn the gas valve switch to the OFF position DO NOT FORCE 5 Replace the control access panel Post Start Check List After the entire control circuit has been energized and the heatin...

Page 18: ...on sumed per hour by the BTU content of the gas in your particular locality Contact your gas company for this information since it varies widely from city to city Table 15 Gas Rate Cubic Feet Per Hour1 1 EXAMPLE By actual measurement it takes 38 seconds for the hand on the 1 cubic foot dial to make a revolution with just a 100 000 BTUH furnace running Using this information locate 38 seconds in th...

Page 19: ...U 43 GND BLK WHT 11 CONTACTOR COIL SINGLE POLE CONTACTOR RED 45 BLU 42 BLU 30 PUR 2 YEL 21 BLK YEL 18 GRN 44 LINE VOLTAGE FIELD INSTALLED POWER LOW VOLTAGE FIELD INSTALLED CONTROL 5 4 3 2 6 1 BLK BRN GRN 10 RED COOLING UNIT WITH GAS HEAT CONNECTION WIRING DIAGRAM CAUTION OPEN ALL DISCONNECTS BEFORE SERVICING THIS UNIT 1 ALL FIELD WIRING TO BE ACCOMPLISHED FOLLOWING CITY LOCAL AND OR NATIONAL CODES...

Page 20: ... CONTACTOR COIL 4 2 F H C DUAL CAPACITOR START CAP 1 2 5 START RELAY T1 L1 L2 T2 DRAFT MOTOR CONTROL BOARD RELAY CAP BLU RED WHT GRN Y R G C THERMOSTAT RED GRN ORG RED RED BLK ROLLOUT PRESSURE LIMIT FS L1 IND SPARK TRANSFORMER YEL YEL GRN ORG 4 5 6 1 2 3 7 8 9 3 2 1 24V COM Y SPD G SPD W SPD W Y O R G C RED ORG IGNITOR FLAME SENSOR GAS VALVE CONTROL BOARD W YEL BLU YEL RED WHT 3A FUSE BLK RED RED ...

Page 21: ...TACTOR RED 45 BLU 42 BLU 30 PUR 2 YEL 21 BLK YEL 18 GRN 44 LINE VOLTAGE FIELD INSTALLED POWER LOW VOLTAGE FIELD INSTALLED CONTROL 5 4 3 2 6 1 BLK BRN GRN 10 RED COOLING UNIT WITH GAS HEAT CONNECTION WIRING DIAGRAM CAUTION OPEN ALL DISCONNECTS BEFORE SERVICING THIS UNIT 1 ALL FIELD WIRING TO BE ACCOMPLISHED FOLLOWING CITY LOCAL AND OR NATIONAL CODES IN EFFECT AT THE TIME OF INSTALLATION OF THE UNIT...

Page 22: ...MOTOR 5 3 C 1 HI PRESS CONTACTOR COIL 4 2 F H C DUAL CAPACITOR T1 L1 L2 T2 DRAFT MOTOR CONTROL BOARD RELAY CAP BLU RED WHT GRN Y R G C THERMOSTAT RED GRN ORG RED RED BLK ROLLOUT PRESSURE LIMIT FS L1 IND SPARK TRANSFORMER YEL YEL GRN ORG 4 5 6 1 2 3 7 8 9 3 2 1 24V COM Y SPD G SPD W SPD W Y O R G C RED ORG IGNITOR FLAME SENSOR GAS VALVE CONTROL BOARD W YEL BLU YEL RED WHT 3A FUSE BLK RED BRN RED OD...

Page 23: ...y Manifold sets must be at least 700 psig high side and 180 psig low side with 550 psig retard All hoses must have a service pressure rating of 800 psig Leak detectors must be designed to detect HFC refrigerants Systems must be charged with liquid refrigerant Use a commercial type metering device in the manifold hose R 410A can only be used with POE type oils POE type oils rapidly absorb moisture ...

Page 24: ...1183746 UIM B 0215 24 Johnson Controls Unitary Products NOTES ...

Page 25: ...L1 to L2 L2 to L3 L1 to L3 Total amperes L1 L2 L3 Compressor amperes L1 L2 L3 Measured voltage R and C outdoor unit control board Electrical Connections Inspection Check all that apply Equipment Data Additional Kits Accessories Installed Check all that apply Equipment Data Blower Type Set Up Supply air dry bulb temperature ADJUST A B C D A B C D Total external static pressure Supply static inches ...

Page 26: ...ion and Cycle Test Operate the unit through continuous fan cycles from the thermostat noting and correcting any problems Operate the unit through cooling cycles from the thermostat noting and correcting any problems Job site has been cleaned indoor and outdoor debris removed from job site Tools have been removed from unit All panels have been installed TXV Fixed Orifice Liquid line temperature Suc...

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