Toshiba RAS-B13N3KVP-E - Defrost Control (Only in Heating Operation)

– 33 –
Item
Operation flo
w and applicable data, etc.
Description
7. Defrost control
(Only in heating
operation)
(This function removes frost adhered to the outdoor
heat e
xchanger.)
The temper
ature sensor of the outdoor heat ex-
changer (T
e sensor) judges the frosting status of the
outdoor heat e
xchanger and the defrost operation is
perf
ormed with 4-way valve reverse defrost system.
The necessity of defrost operation is
detected b
y the outdoor heat exchanger
temper
ature. The conditions to detect the
necessity of defrost oper
ation differ in A,
B
, or C zone each. (Table 1)
<Defr
ost operation>
• Defrost oper
ation in A to C zones
1)
Stop operation of the compressor for
20 seconds
.
2)
Invert (ON) 4-way valve 10 seconds
after stop of the compressor
.
3)
The outdoor fan stops at the same time
when the compressor stops
.
4) When temperature of the indoor heat
e
xchanger becomes 38
°C or lo
wer,
stop the indoor f
an.
<Finish of defr
ost operation>
• Retur
ning conditions from defrost
oper
ation to heating operation
1)
Temperature of outdoor heat exchanger
r
ises to +8°
C or higher
.
2
) Temperature of outdoor heat exchanger
is k
ept at +5°
C or higher f
or 80 seconds.
3)
Defrost operation continues for
15 min
utes.
<Returning fr
om defrost operation>
1)
Stop operation of the compressor for
approx. 50 seconds.
2) Invert (OFF) 4-way valve approx. 40
seconds after stop of the compressor
.
3)
The outdoor fan starts rotating at the
same time when the compressor star
ts.
T
able 1
* The minimum value of Te sensor 10 to 15 minutes
after star
t of operation is stored in memory as Te0.
–5˚C
0
’
10
’
15
’
27
’40”
34
’
–
7˚
C
–
20˚
C
Oper
ation time
(Min
ute)
Star
t of heating operation
*
Outdoor heat exchanger temperature
C zone
A z
one
B z
one
A zone
B zone
C zone
When Te0 - TE ≥ 2.5 continued for 2 minutes in A zone,
defrost oper
ation starts.
When the operation continued for 2 minutes in B zone,
defrost oper
ation starts.
When Te0 - TE ≥ 3 continued for 2 minutes in C zone,
defrost oper
ation starts.
FILE NO. SVM-12051