MAJOR COMPONENTS
Variable speed Control Board
The HP control board controls the following functions:
SCompressor speed S Contactor operation
S Outdoor fan motor operation S Reversing valve operation S Defrost operation
S Low ambient cooling
S Crankcase heater operation S Pressure switch monitoring S Time Delays
S Pressure Transducer
S .EXV operation control
S .Inverter communication and control
Inverter
The inverter is located inside the control box. This is an air-cooled device that communicates with the control board and drives the compressor to the demanded RPM. When the contactor closes, it powers the inverter with line voltage. The inverter converts the line voltage to 410 volts DC. The inverter then converts DC voltage into 3-phase variable frequency and variable voltage.
NOTE: Manually closing the contactor will not cause the unit to operate. The unit must be operated with an Evolution Control. A standard thermostat will allow operation only in the emergency mode (high speed heating or cooling).
Motor Control Drive (Inverter):
S Converts the sinusoidal AC input mains voltage into a variable frequency AC output generated used PWM modulation of the output.
SDrive adjusts the output voltage to run the compressor at the correct speed at any load point in the envelope.
SThe drive actively controls the motor current to insure the proper torque is provided for the given loading condition.
SThe drive control algorithms insure the magnetic field set up in
the motor is synchronized with the rotor insuring smooth efficiency operation.
S The drive actively controls the input current at heavy loading conditions to insure the input power factor to the drive is >0.95.
Variable Speed Compressor
This unit contains a variable speed compressor that has a wide operating range. This compressor can only be operated by the specific inverter supplied with the unit.
Motor Control Drive + BPM together:
SThrough the combination of the drive and motor, the system is able to operate over a wide speed range.
SThe drive provides protection of the system to various abnormal conditions including limiting the compressor envelope of operation to appropriate boundaries.
SProvides many pieces of system data as feedback to the system controller.
SAllows operation at least than full performance in case of system faults or issues.
!CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage and/or improper operation.
Do not attempt to apply line voltage directly to the compressor. This will destroy the compressor.
Compressor Brush-less Permanent Magnet Motor (BPM):
SThe motor inductance reacts to the drive current and a sinusoidal
current is induced through the motor windings.
S The sinusoidal current sets a rotating magnetic field, at the frequency set by the drive.
SThe magnets enable the motor to synchronize to that frequency, set by the drive.
SSupplies the mechanical power afforded to it by the drive voltage, current and frequency.
Electronic Expansion Valve (EXV)
This unit uses an electronic expansion valve for refrigerant metering in the heating mode. The control board drives the EXV to its proper position based on the operating mode and conditions. The Evolution Control Service mode allows for manual opening and closing of the EXV for troubleshooting and pump down.
Field control Connections
For normal operation use the ABCD Evolution connections only. Only two wires, AB are required. See Fig. 18. Discrete inputs (Y,C,
O)are available for emergency operation if the Evolution Bus is not in operation.
Pressure Transducer (SPT)
A 5 VDC output low pressure transducer that provides a 0-5 VDC data for interpretation by the control board for a 0 to 200 psig range of pressure at the suction tube. This interpreted pressure data is then intelligently used by the control board for low pressure cut-out, loss of charge management, compressor overall envelope management, oil circulation management, lubrication management and EXV control. (See Fig. 17.)
Compressor Control Contactor
The contactor has a 24 volt coil. The electronic control board controls the operation of the contactor.
TROUBLESHOOTING
Systems Communication Failure
If communication with the Evolution control is lost with the User Interface (UI), the control will flash the appropriate fault code (see Table 7). Check the wiring to the User Interface and the indoor and outdoor units and power.
Model Plug
Each control board contains a model plug. The correct model plug must be installed for the system to operate properly (see Table 3).
Table 3 – Model Plug Information
MODEL | | PIN RESISTANCE |
MODEL PLUG | (K---ohms) |
NUMBER | NUMBER | | |
| | Pins 1---4 | Pins 2---3 |
| | | |
280ANV024 | HK70EZ001 | 5.1K | 11K |
| | | |
280ANV036 | HK70EZ002 | 5.1K | 18K |
| | | |
280ANV048 | HK70EZ003 | 5.1K | 24K |
| | | |
280ANV060 | HK70EZ004 | 5.1K | 33K |
| | | |
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.
