Toshiba RAV-SM304MUT-E Service Manual page 31

No. Item
8 Freeze preventive control
(Low temperature release)
AMP Air Conditioning
Outline of specifications
1) The cooling operation (including Dry operation) is
performed as follows based on the detected
temperature of Tc sensor or Tcj sensor.
When [J] zone is detected for 6 minutes
(Following figure), the commanded frequency is
decreased from the real operation frequency.
After then the commanded frequency changes
every 30 seconds while operation is performed in
[J] zone.
In [K] zone, time counting is interrupted and the
operation is held.
When [ I ] zone is detected, the timer is cleared
and the operation returns to the normal operation.
If the commanded frequency becomes S0
because the operation continues in [J] zone, the
return temperature A is raised from 5°C to 12°C
until [ I ] zone is detected and the indoor fan
operates with [L] mode.
˚C
5 I
2
In heating operation, the freeze-preventive control
works if 4-way valve is not exchanged and the
following conditions are satisfied.
(However the temperature for J zone dashing control
is changed from 2°C to –5°C.)
<Conditions>
Q R
• When or is established 5 minutes after
activation.
Q
Tcn ≤ Tc (n – 1) – 5
R
Tcn < Tc (n – 1) – 1 and Tcn ≤ Ta < 5°C
– 31 –
Tcj:
Indoor heat exchanger
sensor temperature
A
K
J
Tcn:
Tc temperature when 5
minutes elapsed after
activation
Tc (n – 1):
Tc temperature at start
time
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Remarks