Toshiba HWT-602S21SM3W-E(TR) Service Manual page 84

Item
7-3. 2) Control at the time of heating heater operation
Hydro Unit Control • Controlled Object: Backup heater, Booster heater
The backup heater control starts when 3 minutes has passed after the heating heater operation started.
The backup heater control increases, decreases, or maintains the number of heaters every 10 minutes (DN)
depending on the difference between the heating set temperature (TSC_F) and the heater outlet temperature
(THO). Note that when the heating set temperature (TSC_F) +2K is reached, the unit stops energizing the
heater.
TSC_F+2
TSC_F-0
TSC_F-2
Status
Heater 1
Heater 2
Heater 3
Heater 4
HWT-**M3W-E model has the backup heater 1 of 3 kW only.
HWT-**T6W-E model has the backup heater 2 of 3 kW. (Total 6 kW)
Booster heater operation come only output signal. (Booster heater activate under heater only mode).
Related DN
DN
20
21
33
34
2-3) Heater control at the time of defrosting
• Object to be controlled: Backup heater
When a defrosting operation starts during the heating heat
pump operation, the unit energizes a backup heater (3 kW)
according to the heater outlet temperature sensor (THO) and
the set temperature (TSC_F) as shown in Figure.
1) When the heater outlet temperature sensor (THO) drops to
the temperature of 2°C below the TSC_F-β, the backup
heater is energized.
β can be changed for energy saving.
Defrosting ends according to the usual heater control.
Related DN
DN
B8
2-4) Forcible heater energization
To prevent freeze, the unit energizes or stops energizing a backup heater (3 kW) regardless of the unit status, not
operated or in operation.
• Object to be controlled: Backup heater
1) Energization start condition: TWO < 4 or TWI < 4 or THO < 4
2) Energization stop condition: TWO ≥ 5 and TWI ≥ 5 and THO ≥ 5
Defrosting ends according to the usual heater control.
Operation flow and applicable data, etc.
THO
E zone
75
D zone
C zone
B zone
A zone
Heater ON/OFF
Backup-heater 3 kW = ON
Backup-heater 6 kW = ON
Backup-heater 9 kW = ON
Heater 3 + Booster heater
Setting item
Hot water supply heat pump start temperature
Hot water supply heat pump stop temperature
Heater control of down time
Heater control of up time
Setting item
β: 0 = 0K, ..., 4 = 40K
Recommendation: β = 2 (20K)
Abnormality detection (A02 displayed)
Diff: 2K
Heater off
Heater output down every
5, 10, 15, or 20 minutes
Diff: 2K
KEEP
Diff: 2K
Heater output up every
10, 20, 30, or 40 minutes
Default
38°C
52°C
1:10 min
0:10 min
THO
TSC_F - β
Status
Heater 1
Default Setting available range
0K 0K - 40K
83
Setting available range
20 - 45°C
40 - 65°C
0: 5 min 2: 15 min 3: 20 min
1: 20 min 2: 30 min 3: 40 min
Heater OFF
Diff: 2K
β
Heater ON
Heater ON/OFF
Backup heater 3 kW = ON