Multi-Zone Technical Overview

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ENGLISH
INTRODUCTION
OVERVIEW & INTRODUCTION
Multi-Zone Outdoor
Multi-Zone Outdoor
The Control of the Outdoor Unit Expansion Valve
When unit starts, the EEV valves will energize and change to a
standard opening. When operation starts, the EEV will change
position to keep the suction vapor superheat level at around
10°F.
When the unit is shut o the opening size of the expansion
valve of the indoor unit is 5 steps;
Four-way valve control
For the details of defrosting four-way valve control, see the
defrosting process.
Under heating mode, the four-way valve opens. If the
compressor does not start or changes to a non-heating
mode, the compressor will be stopped for 2 minutes, and then
the four-way valve will shift.
When the compressor rst starts
The compresor will start in low frequency. After a brief time
delay, the compressor will come up to operating speed to
meet the demand requirement for capacity.
The outdoor fan control (exchange fan)
When adjusting the fan speed, the unit should remain at each
speed for 30+ seconds to avoid speed-change malfunctions.
In Cooling Mode, the wait time between speed levels should
be 15 seconds.
The outdoor fan control when in cooling or dehumidifying
mode
Five seconds after compressor starts, the outdoor fan will
start running at medium speed. After 30 seconds, it begins
to control the fans peed according to the temperature
conditions of the outdoor environment.
Over-temperature Heat Mode Indoor Coil
The over-temperature routine will protect the system from excessive high indoor coil temperature during heat mode operation.
The routine will initiate if the indoor coil temperature sensor reads temperatures in excess of 131F. Conditions that cause high
indoor coil temperature include indoor fan failure, dirty indoor coil and operating the system in heat mode when outdoor air
temperatures exceed operating limit. (Too warm outside)
Should this routine be initiated, the system will reduce compressor frequency until the indoor coil temperature reaches 117F.
Once this is achieved, the system will return to normal operation.
149°F
131°F
138°F
117°F
124°F