background image

5285473-UIM-E-1217

Johnson Controls Unitary Products

17

COOLING SEQUENCE OF OPERATIONS

When the thermostat calls for “COOL,” the thermostat terminals “G” and
“Y1” are energized, which signals the compressor, outdoor fan and
indoor blower to run on first stage cooling.

With a call for “Y1,” the circulating fan is energized at first stage cooling
speed.

The control cycles the compressor and indoor fan to second stage cool-
ing speed anytime a second stage cooling (Y2) call is received during a
first stage cooling (Y1) call. The control does not operate on second
stage cooling without a call on the “Y2” thermostat input.

When the thermostat is satisfied, terminals “G” and “Y” are de-ener-
gized, de-energizing the compressor and outdoor fan.

After a cool fan off delay timing of 30 seconds, the circulating fan is de-
energized.

Dehumidification/Humidity Switch Input

This model unit features a built in de-humidification feature for
advanced dehumidification during cooling operation. The unit indoor
blower control is designed to work with a humidity control that closes
when the humidity is below the set-point. The control is open when the
humidity is above the set-point. This humidity control may be referred to
as a humidistat or dehumidistat.

To use this feature, the control “HUM STAT” jumper must be set to
“YES,” the AC / HP jumper must be set to “A/C,” and a humidistat is
connected from the low voltage “R” and “HUM” color coded leads.
During cooling operation if the humidity level is above the humidistat set
point, the indoor blower speed is reduced by approximately 15%.

Safety Controls

The control circuit includes the following safety controls:

High Pressure Switch (HP) -

 This switch protects against excessive

discharge pressures due to a blocked condenser coil or a condenser
motor failure (switch opens at 650 ± 

25 psig and closes at 450 ± 

25

psig).

Low Charge Switch (LCS) - 

The switch protects against loss of charge

due to a leak in the system. 

The high pressure switch is specifically designed to operate with R-
410A systems. R-22 pressure switches must not be used as replace-
ments for the R-410A pressure switches.

Indoor Circulating Blower

When the thermostat calls for “FAN,” the thermostat terminal “G” is
energized signaling the indoor blower control board to operate the cir-
culating blower to run continuously. The circulating blower airflow is
approximately 63% of the “HIGH COOL” airflow selected on the indoor
blower control board.

If a call for “COOL” occurs on “Y1,” the indoor blower runs at the “LOW
COOL” speed based on the “COOL” jumper setting. If a call for cool is
present on “Y1”+”Y2,” the indoor blower runs at the “HIGH COOL”
speed based on the “COOL” jumper setting.

If a call for “HEAT” occurs “W1” or “W1”+“W2”, the circulating blower
runs at the heat speed based on the “HEAT” jumper setting.

When the thermostat ends the call for “FAN,” the thermostat terminal
“G” is de-energized, and the indoor blower control board stops the cir-
culating blower operation.

Delay Profiles

The Delay Profiles are shown in Table 15 for each Delay jumper setting. 

The levels shown in the Pre-Run, Short-Run, and Run Periods are a
percentage of the blower speed corresponding to the thermostat call. 

The Post-Run and Off Delay levels are derived from the level of the pre-
vious state, not the blower speed corresponding to the thermostat call. 

If in Delay Profile B and in the Short-Run Period (82% of capacity) and
the thermostat call is removed, this causes the control to enter the Post-
Run state. The Post-Run state level for Delay Profile B is 100% of the
previous level, so the level during the Post-Run state is 82%. 

Table 13: 

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 Flashes

Low flame current 

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 greater than 
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 code

11 Red Flashes

Limit/Rollout switch open between 5 and 15 
minutes

12 Red Flashes

Model plug not inserted

Wiring Related Faults

9 Red Flashes

Incorrect line voltage polarity

4 Amber Flashes

Y

 

thermostat demand without a G

 WARNING

The ability to properly perform maintenance on this equipment
requires certain expertise, mechanical skills, tools and equipment. If
you do not possess these, do not attempt to perform any mainte-
nance other than those procedures recommended in this Installation
Manual. Failure to heed this warning could result in serious injury
and possible damage to this equipment.

!

TABLE 14 : Delay Profile Descriptions

Delay 

Profile

Period

Cooling

Level%

Time in State 

(Minutes)

A

Pre-Run

Bypass

Bypass

Short-Run

Bypass

Bypass

Run

100

No Limit

Post-Run*

100

1

Off Delay*

Bypass

Bypass

B

Pre-Run

50

2

Short-Run

82

5

Run

100

No Limit

Post-Run*

100

1

Off Delay*

Bypass

Bypass

C

Pre-Run

Bypass

Bypass

Short-Run

Bypass

Bypass

Run

100

No Limit

Post-Run*

100

1

Off Delay*

50

1

D

Pre-Run

Bypass

Bypass

Short-Run

63

1.55

Run

100

No Limit

Post-Run*

100

1

Off Delay*

63

0.5

Summary of Contents for PCG6B42

Page 1: ...Feet Per Hour 20 SECTION I GENERAL INFORMATION These are electric cooling gas heating units designed for outdoor instal lation Only gas piping electric power and duct connections are required for ins...

Page 2: ...ation in this manual is not followed exactly a fire or explosion may result causing property damage personal injury or loss of life Do not store or use gasoline or other flammable vapors and liquids i...

Page 3: ...stallation only 2 Condenser coils must have an unlimited supply of air Where a choice of location is possible position the unit on either north or east side of building 3 Suitable for mounting on roof...

Page 4: ...the spreader bars exceed the largest dimension across the unit Units may be moved or lifted with a forklift Slotted openings in the base rails are provided for this purpose WARNING Do not permit over...

Page 5: ...rances1 2 Direction Distance in Direction Distance in Top3 36 Power Entry Right Side 36 Side Opposite Ducts 36 Left Side 24 Duct Panel 0 Bottom4 1 NOTES 1 A 1 clearance must be provided between any co...

Page 6: ...is required Filters must always be used and must be kept clean When filters become dirt laden insufficient air is delivered by the blower the unit efficiency is decreased operating costs are increased...

Page 7: ...uld be field provided for the unit If any of the wire supplied with the unit must be replaced replacement wire must be of the type shown on the wiring diagram Electrical service must be sized properly...

Page 8: ...stages 2 2 2 2 2 2 2 2 2 2 Temperature Rise Range High Fire F 40 70 40 70 40 70 40 70 Temperature Rise Range Low Fire F 25 55 25 55 25 55 25 55 Max Static Pressure w c 0 5 0 5 0 5 0 5 Max Outlet Air T...

Page 9: ...value should be checked with the local gas utility Direct Drive Indoor Fan Data Fan Size Inch 11 x 10 11 x 10 11 x 10 11 x 10 Type Centrifugal Centrifugal Centrifugal Centrifugal Motor HP each 1 2 3...

Page 10: ...imum capacity of pipe in cubic feet of gas per hour based upon a pres sure drop of 0 3 inch water column and 0 6 specific gravity gas Length In Feet Nominal Inches Iron Pipe Size 1 2 3 4 1 1 1 4 10 13...

Page 11: ...nches WC 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 1 0 SCFM SCFM SCFM SCFM SCFM SCFM SCFM SCFM SCFM SCFM 36065 High Cool A 1371 1354 1303 1257 1209 1148 1084 1008 934 878 B 1293 1246 1206 1152 1098 1028 938...

Page 12: ...1645 1612 1572 1520 1477 1419 1384 1327 B 1506 1468 1441 1404 1358 1302 1259 1203 1159 1101 C 1322 1278 1238 1191 1138 1077 1030 975 920 859 D 1251 1205 1157 1107 1051 987 938 884 824 761 Low Heat A 1...

Page 13: ...0 872 810 High Heat A 2114 2046 1974 1914 1874 1815 1745 1696 1645 1582 B 1982 1930 1887 1844 1806 1752 1697 1643 1604 1545 C 1785 1746 1720 1687 1647 1596 1551 1494 1459 1402 D 1614 1578 1554 1520 14...

Page 14: ...0 1232 1181 1135 C 1410 1361 1307 1255 1204 1155 1100 1044 992 938 D 1323 1270 1213 1156 1104 1052 993 933 880 821 Low Heat A 1594 1553 1507 1462 1415 1369 1321 1274 1223 1178 B 1323 1270 1213 1156 11...

Page 15: ...oved the control de energizes the inducer without post purge and returns to standby If the pressure switch does not close within 5 seconds of inducer ener gizing the control board flashes 3 on the LED...

Page 16: ...trol faults reset after 60 minutes 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...

Page 17: ...door blower runs at the HIGH COOL speed based on the COOL jumper setting If a call for HEAT occurs W1 or W1 W2 the circulating blower runs at the heat speed based on the HEAT jumper setting When the t...

Page 18: ...t operate follow the instructions To Turn Off Gas To Appliance and call service technician or gas supplier To Turn Off Gas To Unit 1 Set the thermostat to the OFF position 2 Turn off all electric powe...

Page 19: ...the high fire manifold pressure or the low fire manifold pressure 1 Refer to Figure 10 for location of pressure regulator adjustment cap and adjustment screws on main gas valve 2 Turn gas and electric...

Page 20: ...d 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 the first column of Table 17 Read across to the column headed 1 Cub...

Page 21: ...ten as necessary to keep the coil clean If water is used to clean the coil be sure that the power to the unit is shut off prior to cleaning TROUBLESHOOTING FIGURE 12 Measuring External Static Pressure...

Page 22: ...ONAL FAULT CODES NORMAL OPERATION GREEN HEARTBEAT Normal Operation Standby mode AMBER HEARTBEAT Call for furnace heat active RAPID GREEN FLASHES Control in Factory Test mode 4 AMBER FLASHES No G from...

Page 23: ...PLACED WITH TYPE 105 C 600 VOLT WIRE OR EQUIVALENT AND CLEARLY RENUMBERED FOR IDENTIFICATION VERIFY PROPER OPERATION AFTER SERVICING 3 FACTORY WIRED FOR 230 VOLT THREE PHASE SUPPLY POWER FOR 208 VOLT...

Page 24: ...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 re...

Page 25: ...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 Addition...

Page 26: ...cle 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 pro...

Reviews: