Troubleshooting

If the compressor fails to operate with a cooling call, Table 4 can be used to verify if there is any damage to the compressor windings causing system malfunction.

Table 4 – Winding Resistance

	Winding resistance at 70_F +/--- 20_F
Winding		(21.11_C +/--- 11.11_C)
Winding	187B024	187B036 /	187B048	187B060
		187B036 /
		180B036
		180B036
Start (S---C)	2.74	1.98	1.55	0.6
Run (R---C)	0.8	0.75	0.48	0.49

Systems Communication Failure

If communication with the Evolution Control is lost with the user interface, the control will flash the appropriate fault code. (See Table 6) Check the wiring to the User Interface, indoor and outdoor units.

Model Plug

Each control board contains a model plug. The correct model plug must be installed for or the system to operate properly (see Table 5).

Table 5 – Model Plug

Model	Model Plug	Pin Resistance
Model	Model Plug	(k - Ohms)
Number	Number	(k - Ohms)
Number	Number	Pin 1 - 4	Pin 2 - 3
		Pin 1 - 4	Pin 2 - 3
187B024	Hk70EZ040	18K	75K
187B036	Hk70EZ042	18K	120K
180B036	Hk70EZ011	5.1K	150K
187B048	Hk70EZ044	18K	180K
187B060	Hk70EZ046	18K	270K

The model plug is used to identify the type and size of unit to the control.

On new units, the model and serial numbers are input into the board’s memory at the factory. If a model plug is lost or missing at initial installation, the unit will operate according to the information input at the factory and the appropriate error code will flash temporarily.

An RCD replacement board contains no model and serial information. If the factory control board fails, the model plug must be transferred from the original board to the replacement board for the unit to operate.

NOTE: The model plug takes priority over factory model information input at the factory. If the model plug is removed after initial power up, the unit will operate according to the last valid model plug installed, and flash the appropriate fault code temporarily.

Pressure Switch Protection

The outdoor unit is equipped with high and low pressure switches. If the control senses the opening of a high or low pressure switch, it will respond as follows:

1.De-energize the appropriate compressor contactor,

2.Keep the outdoor fan operating for 15 minutes,

3.Display the appropriate fault code (see Table 6).

4.After a 15 minute delay, if there is still a call for cooling and the LPS or HPS is reset, the appropriate compressor contac- tor is energized.

5.If LPS or HPS has not closed after a 15 minute delay, the outdoor fan is turned off. If the open switch closes anytime after the 15 minute delay, then resume operation with a call for cooling.

6.If LPS or HPS trips 3 consecutive cycles, the unit operation is locked out for 4 hours.

7.In the event of a high pressure switch trip or high pressure lockout, check the refrigerant charge outdoor fan operation and outdoor coil for airflow restrictions.

8.In the event of a low pressure switch trip or low pressure lockout, check the refrigerant charge and indoor airflow.

Control Fault

If the outdoor unit control board has failed, the control will flash the appropriate fault code. (See Table 6) The control board should be replaced.

Brown Out Protection

If the line voltage is less than 187v for at least 4 seconds, the appropriate compressor contactor and fan relay are de-energized. Compressor and fan operation are not allowed until voltage is a minimum of 190v. The control will flash the appropriate fault code (see Table 6)

230 V Brown Out Protection Defeated:

The brownout feature can be defeated if needed for severe noisy power conditions. This defeat should always be a last resort to solving the problem. Defeat is available on the User Interface setup screen (available with SYSTXBBUID01-C UI) or can be initiated through the forced defrost pins for non-communicating systems as follows:

The brownout toggle is accomplished by shorting the defrost pins from power up with the OAT and OCT sensor connector removed. After 3 seconds, the status of the force defrost short and the OAT/OCT as open will be checked. If correct, then the brownout will be toggled.

SStatus code 6 shows the brownout is disabled. S Status code 5 shows the brownout is active.

After the brownout defeat is set, power down and reinstall the OAT/OCT sensor and remove the short from the forced defrost pins. As long as the short on the forced defrost remains, the OAT and OCT faults will not be cleared. The code will continue to be flashed.

The control is shipped with the brownout active. The change in status is remembered until toggled to a new status. A power down/power up sequence will not reset the status. It may be necessary to do the toggle twice to cycle to the desired state of the defeat.

230V Line (Power Disconnect) Detection

If there is no 230v at the compressor contactor(s) when the indoor unit is powered and cooling demand exists, the appropriate error code is displayed (see Table 6). Verify that the disconnect is closed and 230v wiring is connected to the unit.

Compressor Voltage Sensing

The control board input terminals labeled VS and L2 (see Fig. 6) are used to detect compressor voltage status, and alert the user of potential problems. The control continuously monitors the high voltage on the run capacitor of the compressor motor. Voltage should be present any time the compressor contactor is energized, and voltage should not be present when the contactor is de-energized.

Contactor Shorted Detection

If there is compressor voltage sensed when there is no demand for compressor operation, the contactor may be stuck closed or there is a wiring error. The control will flash the appropriate fault code.

Compressor Thermal Cutout

If the control senses the compressor voltage after start-up, and is then absent for 10 consecutive seconds while cooling demand exists, the thermal protector is open. The control de-energizes the compressor contactor for 15 minutes, but continues to operate the outdoor fan.

The control Status LED will flash the appropriate code shown in Table 6. After 15 minutes, with a call for low or high stage cooling, the compressor contactor is energized. If the thermal protector has not reset, the outdoor fan is turned off. If the call for cooling continues, the control will energize the compressor contactor every 15 minutes. If the thermal protector closes, (at the next 15 minute interval check), the unit will resume operation. If the thermal

187B / 180B

187B specifications

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