Defrost Operation - Toshiba RAS-07EKH Service Manual

8-17. Defrost Operation

8-17-1. Condition to Start the Defrost Operation
Defrost operation starts when the elapsed time is
longer than 40 to 90 minutes, whichever specified.
Note:
• When the high-temperature limit control opera-
tion (with the outdoor fan OFF) is performed for
a total of 90 minutes, defrost operation starts and
continues for 10 minutes.
The cumulative operation time is cleared only
when the defrost operation is completed.
Fig. 8-32
8-17-2. Defrost Operation Time Control
(1) The heating operation is performed for at least
40 minutes.
(2) The maximum defrost operation time is 6 min-
utes. The defrost operation time for the 4th cycle
is 10 minutes. (When the outdoor temperature is
very lower, however, the defrost operation time
is 10 minutes.)
Fig. 8-33
8-17-3. Ending condition at Defrost Operation
When the compressor current becomes 5.5A or more
during defrost operation, the defrost operation stops
and the heat operation restarts. (The current sensor
detects the compressor current.) The defrost opera-
tion continues for at most 6 minutes.
DEFROST LAMP:
• During defrost operation, the PRE-DEF. lamp
is on and the indoor and outdoor fans are off.
• The compressor start protection timer is inter-
locked with the PRE-DEF. lamp. So the PRE-
DEF. lamp is off (the fans stop) for about 3
minutes after the START/STOP button is
turned on. When the compressor is turned on,
the PRE-DEF. lamp comes on. After the heat
exchanger is preheated to about 30°C or
higher, the PRE-DEF. lamp goes off, and the
indoor fan starts.
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