Toshiba ESTIA HWS-1501CSHM3-E, Service Manual

Page: 79 / 212

78
8-4.
Outdoor unit
control 6) Defrosting control
This control defrosts the outdoor heat exchanger. The temperature sensor (TE sensor) of the outdoor heat exchanger
determines frost formation, and then defrosting is performed in the 4-way valve reverse defrosting method.
1) During a heating operation, defrosting is performed when the TE sensor meets any of the conditions in A through D
zones.
2) During defrosting, when TE sensor maintains 12°C or higher for 3 seconds or 7°C TE < 12°C for a minute, the
defrosting ends. Also, when defrosting continues for 10 minutes even if the TE sensor temperature is below 7°C, the
defrosting ends.
3) After the defrosting, stop the compressor for approx. 40 seconds before starting a heating operation.
4) Switching the jumper "J805" and "J806" of the outdoor control board can change the time of d above mentioned.
(Factory default: 150 minutes)
Jumper switching O: Short circuit ×: Open
Item Operation flow and applicable data, etc.
Heating operation starts
-2
-5
-10
-23
(-25)* 2
TE
[
°C
]
0 10 15 39 45 55 [d]
[min]
D zone
A zone
B zone
C zone
*
1
* 1 In 10 to 15 minutes after the heating
operation starts, the lowest value of
TE is recorded as TEO, and the
lowest temperature of To as ToO.
* 2 Inside brackets: For 803H-E
To Normal
A Zone Maintain " (TEO - TE) - (ToO - To) 3°C" for 20 sec
B Zone Maintain " (TEO - TE) - (ToO - To) 2°C" for 20 sec
C Zone
Maintain " TE -23°C" for 20 sec (except 803H-E)
Maintain " TE < -25°C" for 20 sec (803H-E)
D Zone Accumulate compressor operation status of TE < -2°C for 150 min
To Normal
A Zone Maintain " TEO - TE 3°C" for 20 sec
B Zone Maintain " TEO - TE 2°C" for 20 sec
C Zone
Maintain " TE -23°C" for 20 sec (except 803H-E)
Maintain " TE < -25°C" for 20 sec (803H-E)
D Zone Accumulate compressor operation status of TE < -2°C for 150 min
J805 J806 [d]
O O 150 min (Factory default)
O × 90 min
× O 60 min
× × 30 min
ON
OFF
ON
OFF
ON
OFF
500pulse
200pulse
0pulse
0s 30s 40s
Defrosting operation
0s 30s 10s 40s
Outdoor PMV
4-way valve
Outdoor fan
Compressor