Bryant LEGACY 213R Service Manual download pdf (Page 18)

14. Remove jumper between DFT and R terminals. Reconnect

defrost thermostat leads. Failure to remove jumper causes

unit to switch to defrost every 30, 60, or 90 minutes and

remain in defrost for full 10 minutes.

15. Replace control box cover. Restore power to unit.

If defrost thermostat does not check out following above items

or incorr ect calibration is suspected, check for defective

thermostat as follows:

1. Follow items 1-- 5 above.

2. Route sensor or probe underneath coil (or other convenient

location) using thermocouple temperature measuring

device. Attach to liquid line near defrost thermostat. Insulate

for more accurate reading.

3. Turn on power to outdoor unit.

4. Restart unit in heating.

5. Within a few minutes, liquid line temperature drops within a

range causing defrost thermostat contacts to close.

Temperature range is from 33_Fto27_F. Notice

temperature at which ohmmeter reading goes from ∞ to zero

ohms. Thermostat contacts close at this point.

6. Short between the speed--up terminals using a small slotted

screwdriver.

7. Unit changes over to defrost within 21 sec (depending on

timing cycle setting). Liquid line temperature rises to range

where defrost thermostat contacts open. Temperature range

is from 60_Fto70_F. Resistance goes from zero to ∞ when

contacts are open.

8. If either opening or closing temperature does not fall within

above ranges or thermostat sticks in 1 position, replace

thermostat to ensure proper defrost operation.

NOTE: With timing cycle set at 90 minutes, unit initiates defrost

within approximately 21 sec. When you hear the reversing valve

changing position, remove screwdriver immediately. Otherwise,

control will terminate normal 10 -- minute defrost cycle in

approximately 2 sec.

OF2

HK32EA003

QUIET

SHIFT

120

INTERVAL TIMER

OFF

DFT

O R W

Y C

T2 C C O

DFT

T1 Y

SPEEDUP

Speedup

Pins

Defrost interval

DIP switches

Quiet

Shift

A05378

Fig. 11 – HK32EA003 Defrost Control

HK32EA003 Defrost

Control

The HK32EA003 defrost control is used in all 223A and 224A

Legacy Line heat pumps with Puron refrigerant. Its features

include selectable defrost intervals of 30, 60, 90, & 120 minutes,

Quiet Shift, compressor time delay, deluxe defrost speed up

capability. This section describes the sequence of operation and

trouble shooting methods for this control.

Quiet

Shift

This control has the option of shutting down the compressor for 30

seconds going in and coming out of defrost. This is accomplished

by turning DIP switch 3 to the ON position. Factory default is in

the OFF position. Enabling this feature eliminates occasional noise

complaints associated with switching into and out of defrost.

Five-- Minute Compressor

Delay

This control features a 5--minute time delay to protect the

compressor from short cycling. The delay begins counting when

the low voltage is interrupted, and at the end of heating or cooling

cycle.

Sequence of

operation

On power--up (24 volts between R -- C) the 5 minute cycle timer

begins counting down. The compressor will not be energized until

this timer is elapsed.

Cooling

On a call for cooling, thermostat makes R--O, R--Y, and R-- G.

Circuit R--O energizes reversing valve switching it to cooling

position. Circuit R-- Y sends low voltage through the safeties and

energizes the T1 terminal on the circuit board. If the compressor

has been off for 5 minutes, or power has not been cycled for 5

minutes, the OF2 relay and T2 terminal will energize. This will

close the contactor, start the outdoor fan motor and compressor.

When the cycle is complete, R-- Y is turned off and compressor and

outdoor fan should stop. When using Bryant thermostats, the

reversing valve remains energized in the cooling mode until the

thermostat is switched to heat, or the mode it turned of f. The

5--minute time guard begins counting. Compressor will not come

on again until this time delay expires. In the event of a power

interruption, the time guard will not allow another cycle for 5

minutes.

Heating

On a call for heating, thermostat makes R--Y, and R--G. Circuit

R-- Y sends low voltage through the safeties and energizes the T1

terminal on the circuit board. T1 energizes the defrost logic circuit.

If the compressor has been off for 5 minutes, or power has not been

cycled for 5 minutes, the OF2 relay and T2 terminal will energize.

This will close the contactor, start the outdoor fan motor and

compressor .

When the cycle is complete, R--Y is turned off and the compressor

and outdoor fan should stop. The 5 minute time guard begins

counting. Compressor will not come on again until this time delay

expires. In the event of a power interruption, the time guard will

not allow another cycle for 5 minutes.

Defrost

Sequence

The defrost control is a time/temperature control that has field

selectable settings of 30, 60, 90 and 120 minutes. These represent

the amount of time that must pass after closure of the defrost

thermostat before the defrost sequence begins.

The defrost thermostat senses coil temperature throughout the

heating cycle. When the coil temperature reaches the defrost

thermostat setting of approximately 32 degrees F, it will close,

which energizes the DFT terminal and begins the defrost timing

sequence. When the DTF has been energized for the selected time,

the defrost cycle begins. If the defrost thermostat opens before the

timer expires, the timing sequence is reset.

Defrost cycle is terminated when defrost thermostat opens or

automatically after 10 minutes.

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Bryant LEGACY 213R Service Manual Page 18

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