Toshiba MD-VNK802HEXE, Service Manual

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22
7 Auto
capacity
control 1) The outdoor unit determines the operational performance of the indoor unit
according to the difference between TRA and Ts.
* Ts refers to a value corrected in 6.
Ts: Temperature setting
8 PMV control
Suction
temperature
control 1) The Air to Air Heat Exchanger with DX Coil Unit performs PMV control using the
corrected value of each sensor by operation mode.
1) Cool
• Correct the indoor coil temperature (TC1) and coil suction temperature (TSA) to
perform SH control.
2) Heat
• Correct the indoor coil temperature (TC2, TCJ) and coil suction temperature (TSA) to
perform UC control.
2) A value displayed by the monitoring function of the remote controller switch is the
sensor data detected before corrected. (See "Monitoring function of wired remote
controller" on page 47)
Corrected data
• Air Suction Temperature
of direct expansion coil
(TSA)
• Coil Temperature (TC1,
TC2, TCJ)
9 Fan control 1) Judgment by the temperature sensors (TRA, TOA, TSA, TFA) is not performed
while the fan is stopped or within 5 minutes after the operation starts.
• The 5 minutes include the time while defrosting or heat refrigerant (oil) collecting is
performed or after the operation is finished.
2) The fan is stopped during heat refrigerant collecting when the cooling or fan
operation is selected. The fan continues running during cool refrigerant collecting
when the heating operation is selected. The forced fan OFF control is given priority.
TFA: Discharge
temperature
10 Forced
thermo OFF 1) The thermo is turned off forcedly by the Air Suction Temperature of direct expansion
coil (TSA).
• Cool ... TSA < 16 °C, TSA
43 °C
• Heat ... TSA < 7 °C
2) The thermo is turned off forcedly if the supply air fan needs to be stopped.
• If the forced fan OFF conditions are met
3) The thermo is turned off forcedly if the Automatic mode changes to the Bypass
mode.
11 Forced fan
OFF 1) Forced fan OFF judgment
Judge the following conditions 1 – 3 of stoppage and release, and determine the
forced fan OFF operation.
Condition 1
• Stoppage: Air Suction Temperature of direct expansion coil TSA < 3 °C
• Release: Air Suction Temperature of direct expansion coil TSA
5 °C
Condition 2
• Stoppage: Discharge temperature TFA < 3 °C for 20 minutes during humidifying
operation
• Release: Air Suction Temperature of direct expansion coil TSA 5 °C
Condition 3
• Stoppage: Cooling zone is Zone B or Zone C
• Release: Cooling zone is Zone A
No. Item Specification outline Remarks
TRA
Cool Heat
TRA