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5604542-UIM-B-0419

Johnson Controls Ducted Systems

15

Operation

The defrost mode is equivalent to the cooling mode except that the out-
door fan motor is de-energized. The control shall do the following to ini-
tiate a defrost cycle.

• De-energize the outdoor fan.
• Energize the reversing valve.
• Energize the auxiliary heat output through the Wout terminal.
• Begin the maximum defrost cycle length timer.

If the call for heating (Y) is removed from the control during the defrost
cycle, it will terminate the defrost cycle and de-energize the compres-
sor. The control will also stop the defrost cycle length timer but not reset
it. When the control receives another call for heating, it will restart the
defrost cycle and the timer at the point at which the call for heating was
removed. This will happen only if the coil sensor temperature conditions
allow defrost to occur.

Defrost Curves

The control uses a set of defrost curve parameters that are selected
using the defrost curve selection jumper. The location of the defrost
curve selection jumper is shown on the Tabular Data sheet for each
heat pump model.

Defrost Curve Selection

The second page of the tabular data sheet indicates the proper jumper
setting for the specific heat pump model.

The control only reads the jumper input when the Y and W thermostat
inputs are de-energized. If a jumper position is changed while either of
these inputs is energized, the control will not act upon the jumper
changes until the thermostat calls are de-energized or power (24 VAC)
to the control is cycled.

Defrost Cycle Initiation

The control will allow the heat pump to operate in the heating mode until
the combination of outdoor ambient and outdoor coil temperatures indi-
cate that a defrost cycle is necessary. 

The control will initiate a defrost cycle when the coil temperature is
below the initiate point for the measured ambient temperature (See Fig-
ure 15) continuously for 4-1/2 minutes. This delay eliminates unneces-
sary defrost cycles caused by refrigeration surges such as those that
occur at the start of a heating cycle.

The control will initiate a defrost cycle every 6 hours (accumulated com-
pressor run time) to recirculate refrigerant lubricants. This forced
defrost timer will be reset and restarted following the completion or ter-
mination of a defrost cycle.

The control shall initiate a defrost cycle when the Defrost Inhibit Time
Limit has elapsed if the previous defrost cycle was terminated based on
the Maximum Defrost Cycle Time. This shall occur regardless of the liq-
uid line (coil) temperature reading. The coil does not have to be cold for
the unit to be forced into defrost. Once the defrost cycle begins the con-
trol shall follow the normal defrost cycle routine.

The control will also initiate a defrost cycle when the TEST terminals
are shorted. This feature allows an installer or service technician to start
a defrost cycle immediately as required. When the TEST terminals are
shorted for more than 5 seconds with a Y input energized and the pres-
sure switch input is closed, the ASCD will be bypassed, the reversing
valve will be energized, the ODF will be de-energized and the compres-
sor and the Wout terminal to auxiliary heat will be energized.

When the TEST inputs are used to force a defrost cycle, the control will
ignore the state of the coil temperature and outdoor ambient tempera-
ture inputs. The coil does not have to be cold and the outdoor tempera-
ture does not have to be within a certain range for the heat pump to be
forced into a defrost cycle. After the TEST input jumper is removed, the
defrost mode will be terminated as normal. The defrost cycle length
timer will not be started until the TEST input is removed. If the TEST ter-
minals remain shorted, the control will keep the unit in defrost mode.

Defrost Inhibition

The control will not initiate a defrost cycle if the liquid line temperature is
above 40°F unless the defrost cycle is forced using the TEST input, or
the previous defrost exited on maximum time (12 minutes).

The control will also prevent a defrost cycle from being initiated too
soon after the initiation of the previous defrost cycle. When power is
applied to the control and after the completion or termination of each
defrost cycle, the control will start a 40-minute timer. When this timer
expires, the control will allow another defrost cycle when needed. The
timer is based on accumulated compressor run time.

Defrost Termination

The control will terminate the defrost cycle immediately after the liquid
line temperature reaches the terminate temperature or after 12 minutes
of defrost operation. See Figure 15.

The control will do the following to terminate a defrost cycle:

• Energize the outdoor fan.
• De-energize the reversing valve.
• De-energize the auxiliary heat output through the Wout terminal.
• Reset and restart the 40-minute defrost inhibit timer.

 FIGURE 15: 

Defrost Operation Curves

RE

G

ION C

TER

M

INATE CURVE

IN

H

I

B

IT CURVE

INITIA

TE

CUR

VE

RE

G

ION A

RE

G

ION 

B

RE

G

ION D

RE

G

ION E

A

MB

IENT TE

M

PERATURE

LIQUID LINE 

(

COIL

)

TE

M

PERA

TURE

D

e

f

rost

 

prevente

d f

rom

 

starting

N

o

 

ca

ll f

or

 d

e

f

rost

T

ime

 D

e

f

rost

 

(6

 

hour)

 

prevente

d

N

o

 

ca

ll f

or

 D

e

f

rost

T

ime

 D

e

f

rost

 

(6

 

hour)

 

a

ll

owe

d

C

a

ll f

or

 D

e

f

rost

D

e

f

rost

T

erminate

d

A

0144-001

Содержание TH4 Series

Страница 1: ...2 B 32 42 s Gen2 21 LIST OF TABLES Maximum Minimum Operating Limit Conditions 2 R 410A Saturation Properties 8 YHE18 Heat Charging Charts 8 YHE24 Heat Charging Charts 8 YHE30 Heat Charging Charts 9 YH...

Страница 2: ...on the UPGNET web site Provide adequate structural support for the unit ADD ON REPLACEMENT RETROFIT When this unit is being used as a replacement for an R 410A unit it is required that the outdoor uni...

Страница 3: ...HU EUDFH XQGHU FHQWHU RI FRPSUHVVRU 127 QVXUH DGHTXDWH ZDOO VXSSRUW 87 21 6SHFLDO FDUH PXVW EH WDNHQ WR DYRLG UHFLUFXODWLRQ RI GLVFKDUJH DLU WKURXJK RXWGRRU FRLO FIGURE 2 Alternative Installation Clea...

Страница 4: ...taken not to damage the couplings or kink the tubing Use clean hard drawn copper tubing where no appreciable amount of bending around obstruction is necessary If soft copper must be used care must be...

Страница 5: ...ide the grommet back into original position 6 Protect the vapor valve with a wet rag and braze the vapor line con nection to the outdoor unit The nitrogen flow should be exiting the system from the va...

Страница 6: ...place on TXV and install liq uid line to the top of the thermal expansion valve Adjust assembly so liquid line aligns with hole in access panel Hand tighten the liq uid line and apply an additional 1...

Страница 7: ...e for the indoor unit s static pressure vs CFM or to a curve chart CHARGING THE UNIT The factory charge in the outdoor unit includes enough charge for the unit 15 ft 4 6 m of refrigerant piping and th...

Страница 8: ...80 60 70 80 60 70 80 60 70 80 60 70 80 450 Liquid Pressure PSIG 381 427 472 351 394 436 336 384 432 318 363 409 274 324 375 276 318 361 600 Liquid Pressure PSIG 345 389 434 319 355 404 308 354 400 294...

Страница 9: ...58 303 348 1400 Liquid Pressure PSIG 309 351 393 292 336 381 285 332 379 272 315 357 255 299 342 246 290 335 Suction Pressure PSIG 136 109 96 80 60 52 YHE TH4 RHP14L35 CF CM CU42 AE42 AVC42 RFCX42CE C...

Страница 10: ...oor Temperature F 60 70 80 60 70 80 60 70 80 60 70 80 60 70 80 60 70 80 1400 Liquid Pressure PSIG 336 384 433 312 359 406 293 344 395 279 321 364 230 290 349 248 282 316 1600 Liquid Pressure PSIG 320...

Страница 11: ...cess panel FIELD CONNECTIONS POWER WIRING 1 Install the proper size weatherproof disconnect switch outdoors and within sight of the unit 2 Remove the screws at the top and sides of the corner cover Sl...

Страница 12: ...ton be supplied at all times To see connection diagrams of all UPG equipment the Low Voltage System Wiring document is available online at www upgnet com in the Product Catalog Section INDOOR CUBIC F...

Страница 13: ...ing table summarizes the behavior of the control when the two TEST pins are connected More detailed descriptions of the various functions are included in other sec tions of this document TABLE 11 TEST...

Страница 14: ...rrangement of the refrigeration circuit within the coil The control may initiate a defrost cycle even when the coil is not completely cov ered with frost This is normal operation The control regulates...

Страница 15: ...ur regardless of the liq uid line coil temperature reading The coil does not have to be cold for the unit to be forced into defrost Once the defrost cycle begins the con trol shall follow the normal d...

Страница 16: ...te flash code The control will reset the soft lockout condition when any of the follow ing occur after removal of the fault condition 1 Power is cycled to the R or Y inputs of the control This will ca...

Страница 17: ...OPEN REMOTE DISCONNECT SO ELECTRICAL SUPPLY TO HEAT PUMP IS SHUT OFF COMPONENTS SHOWN IN DASH LINES ARE OPTIONAL DUAL CAPACITOR SHOWN SEPARATE CAPACITORS MAY BE USED ON ACTUAL UNIT WIRING MUST CONFOR...

Страница 18: ...RAL 1 2 3 4 5 LEGEND AS AMBIENT SENSOR CAP CAPACITOR CC CONTACTOR COIL CCH CRANKCASE HEATER HPS HIGH PRESS SWITCH HS HEATER SWITCH CS COIL SENSOR LPS LOW PRESS SWITCH RV REVERSING VALVE SC START CAPAC...

Страница 19: ...LE PERSONAL INJURY TO PREVENT ELECTRICAL SHOCK OPEN REMOTE DISCONNECT SO ELECTRICAL SUPPLY TO HEAT PUMP IS SHUT OFF COMPONENTS SHOWN IN DASH LINES ARE OPTIONAL WIRING MUST CONFORM TO NATIONAL AND LOCA...

Страница 20: ...RICAL SHOCK OPEN REMOTE DISCONNECT SO ELECTRICAL SUPPLY TO HEAT PUMP IS SHUT OFF COMPONENTS SHOWN IN DASH LINES ARE OPTIONAL WIRING MUST CONFORM TO NATIONAL AND LOCAL CODES IF ANY OF THE ORIGINAL WIRE...

Страница 21: ...TOR CONNECT L2 OF CONTACTOR TO NEUTRAL 1 2 3 4 5 LEGEND AS AMBIENT SENSOR CAP CAPACITOR CC CONTACTOR COIL CCH CRANKCASE HEATER HPS HIGH PRESS SWITCH HS HEATER SWITCH CS COIL SENSOR LPS LOW PRESS SWITC...

Страница 22: ...5604542 UIM B 0419 22 Johnson Controls Ducted Systems NOTES...

Страница 23: ...ta Venting if applicable Electrical Line Voltage Outdoor Unit Model Outdoor Unit Serial Filter Thermostat Accessories Filter Location s Connections Per Installation Instructions and Local Codes Gas pi...

Страница 24: ...ON OFF or the appropriate Value for the fields that apply to the defrost control board installed Run Time Time and Temperature board only 30 60 or 90 minutes Bonnet Sensor Present HEAT Refrigerant Ch...

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