Hitachi RWM-(H)FSN3E, Service Manual

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5 Control system
SMGB0070 rev. 1 - 08/2011
147
5
Target temperature
• Space heating
Being a parallel system (either Heat Pump or Boiler), water setting will be the same as the water set-point for Heat pump
without outdoor unit temperature restrictions but with restrictions of Maximum water temperature by installer.
• DHW heating
Water set-point for DHW is defined to 80 ºC.
•
Conditions for enabling and disabling boiler.
- Conditions for Enabling
Unit will enable boiler operation if all the following conditions are met.
1 Heating operation selected (Space Heating or DHW)
2
Boiler or Heater complementary heating selected
3
Ambient temperature < Boiler Bivalent point (6-007) (-5ºC Default) more than (Waiting time for boiler) (6-006)
4 Water temperature (Two3) ≤ Water Temperature target (Ttwo) - Supply set point control offset (4ºC default) (6-001)
-
Conditions for Disabling
Unit will not enable boiler operation in any of the following conditions are met:
1 Demand OFF by Room Thermostat
2 Ambient temperature > Boiler Bivalent point (6-007) more than 10 minutes.
User variables:
CODE REF Description Default Value Range Steps Units
6-001 kscob Supply set-point control offset 4.0ºC 0 ~10 1 ºC
6-006 WTBO Waiting time for boiler 30 min 1 ~90 1 min
• Conditions for THERMO ON/OFF Boiler:
- Conditions for Thermo ON Enabling:
1
Water temperature (Two3) < Water temperature setting (Ttwo) - Supply set point offset (4ºC Default)
2
Room thermostat in demand ON.
-
Conditions for Thermo OFF:
When any of Conditions a, b, or c are fulfilled.
a. Measured outlet temp value (Two3) ≥ Water temperature 5ºC.
b. Outlet water temp (Two3) = Max water range temp by installer (1&2 (3-(0)(1)11)) + 2ºC.
c. Thermo OFF by Room Thermostat.
N O T E
Complementary disabling functions for the boiler itself:
In any of the following conditions step will be forced to 0 (boiler off):
• Boiler is disabled by user or thermo OFF by itselfs
• There is an alarm related to boiler