Solahart 151J, Owner'S Manual

Page: 13 / 60

OPERATING YOUR SOLAR WATER HEATER
13
Timer Control of the Tank Boosting
A timer control switch can be installed and will help maximise energy savings with an electrically boosted solar water
heater connected to a
continuous, time of use or extended Off-Peak (overnight and day) electricity supply. Further
information for an electrician on the recommended methods of wiring the timer are outlined in
“Timer Control Switch”
on
page 23.
Programming the Timer
Power must be available to the timer control switch before the booster heating unit can be activated.
The timer control switch should be programmed:
•
to suit the hot water consumption pattern of the household,
•
with the end of the boost period to coincide with the commencement of the evening hot water usage,
•
to enable a boosting period of not less than the recommended continuous length of time for boosting, and
•
for a period when power will be available for the booster heating unit to operate.
It may be necessary to program a second period into the timer, such as prior to the morning hot water usage.
Note: When daylight saving time applies, you may consider resetting the timer accordingly.
The booster heating unit will only activate if heating is required and power is available from the timer. When the water is
below the thermostat setting, the booster heating unit will turn on and heat the water. The booster heating unit will
automatically turn off either when the temperature of the water reaches the thermostat setting or at the end of the timer
period, whichever comes first.
The recommended boosting periods are sufficient to allow the booster heating unit to heat up the boost volume of the solar
storage tank to 60°C where the winter cold water temperatures do not fall below those shown. This may be necessary
during periods of very low solar energy gain through the solar collectors, such as during constant rain or extremely cloudy
weather, particularly in winter when the incoming cold water temperature is lower. The period will also provide a
sufficient heat up time for the electric booster to operate, if required, to satisfy the requirements of AS 3498.
The recommended continuous length of time for boosting (for a 240 V power supply) is:
Cool/temperate climate
Minimum winter cold water supply temperature = 10°C
Thermostat set point = 60°C
Temperature rise = 50°C
Booster Heating Unit 150 model 180 model 300 model
1.5 kW 3 hours 3 ¾ hours 6 hours
1.8 kW 2 ½ hours 3 hours 5 hours
2.4 kW 2 hours 2 ¼ hours 3 ¾ hours
3.6 kW 1 ½ hours 1 ½ hours 2 ½ hours
4.8 kW 1 hour 1 ¼ hours 2 hours
Temperate/sub-tropical climate
Minimum winter cold water supply temperature = 15°C
Thermostat set point = 60°C
Temperature rise = 45°C
Booster Heating Unit 150 model 180 model 300 model
1.5 kW 2 ¾ hours 3 ¼ hours 5 ½ hours
1.8 kW 2 ¼ hours 2 ¾ hours 4 ¾ hours
2.4 kW 1 ¾ hours 2 hours 3 ½ hours
3.6 kW 1 ¼ hours 1 ½ hours 2 ¼ hours
4.8 kW 1 hour 1 hours 1 ¾ hours