FUNCTION AND CONTROL

6.2Description of Each Control Operation

1.Temperature Parameters

Indoor preset temperature (Tpreset )

Indoor ambient temperature (Tamb.) 2. Basic Functions

Once energized, in no case should the compressor be restarted within less than 3 minutes. In the situation that memory function is available, for the first energization, if the compressor is at stop before de-energization, the compressor will be started without a 3-minute lag; if the compressor is in operation before de-energization, the compressor will be started with a 3-minute lag; and once started, the compressor will not be stopped within 6 minutes regardless of changes in room temperature;

(1) Cooling Mode

Working conditions and process of cooling

When Tamb.≥ Tpreset, the unit will enter cooling operation, in which case the indoor fan, the outdoor fan and the compressor will work and the indoor fan will run at preset speed.

When Tamb.≤ Tpreset-28F, the compressor will stop, the outdoor fan will stop with a time lag of 30s, and the indoor fan will run at preset speed.

When Tpreset-28F<Tamb.< Tpreset+34F, the unit will remain at its previous state.

Under this mode, the four-way valve will be de-energized and temperature can be set within a range from 61F to 86F If the compressor is shut down for some reasonS , the indoor fan and the swing device will operate at original state.

 

 

 

 

 

 

Tamb

 

 

 

 

 

 

Start cooling

 

 

 

 

Tpreset

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Original working stat

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Tpreset -28 F

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Stop cooling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6 minutes

 

3 minutes

 

 

 

 

 

 

 

 

 

 

6 minutes

 

Compressor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Outdoor fan

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indoor fan

 

Preset fan Speed

 

 

 

 

 

 

 

 

 

 

 

 

Run

 

Stop

Protection

Antifreeze protection

Under cooling and dry mode, 6 minutes after the compressor is started: If T evap.≤ 36F, the compressor will operate at reduced frequency.

If T evap.≤ -30F is detected for durative 3 minutes, the compressor will stop, and after 30 seconds, the outdoor fan will stop; and under cooling mode, the indoor fan and the swing motor will remain at the original state.

If T evap. ≥ 42F and the compressor has remained at OFF for at least 3 minutes, the compressor will resume its original operation state.

Total current up and frequency down protection

If Itotal≤ A, frequency rise will be allowed; if Itotal ≥B, frequency rise will not be allowed; ifItotal ≥ C, the compressor will run at reduced frequency; and if Itotal ≥D, the compressor will stop and the outdoor fan will stop with a time lag of 30s.

(2) DRY Mode

Working conditions and process of dRY

If Tamb. Tpreset, the unit will enter cooling and dRY mode, in which case the compressor and the outdoor fan will operate and the indoor fan will run at low speed.

If Tpreset-28F Tamb.≤ Tpreset, the compressor remains at its original operation state.

If Tamb.< Tpreset -28F , the compressor will stop, the outdoor fan will stop with a time lag of 30s, and the indoor fan will operate at low speed.

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Friedrich MR12C1H, MW12C1H, MW09C1H, MR09C1H manual Description of Each Control Operation