AUTO
HEAT
COOL
OFF
AUTO
ON
AUTO
HEAT
COOL
OFF
AUTO
ON
Fig. 6. Thermostat mode (Heating) Fig. 6a Thermostat mode (Cooling)
27.7°c
8°C
8°C
8°C
8°C
8°C
28°C
28°C
28°C
28°C
28°C
AUTO
HEAT
COOL
OFF
AUTO
ON
AUTO
HEAT
COOL
OFF
AUTO
ON
Fig. 7 - Heating
Fig. 7A - Cooling
8°c
8°c
8°c
8°c
8°c
28°c
28°c
28°c
28°c
28°c
13:52
AUTO
HEAT
COOL
OFF
AUTO
ON
Fig. 9.
Temperature lowered - cooling
system & fan running.
20.0°c 15.5°c
13:52
PROGRAM OVERRIDE
While running in
AUTO
mode both the heating system and cooling
system will be switched on and off to maintain the selected
temperatures.
The
SEL
(select) button can be
used to select one of three other
modes (See Fig. 10).
With
HEAT
selected only the
heating system will be controlled,
the cooling system being switched
off.
With
COOL
selected only the
cooling system will be controlled,
the heating system being switched
off.
With
OFF
selected both heating
and cooling will be switched off,
except that the HP75 will switch
on the heating system should the
space temperature being sensed
fall below 5°C (41°F).
FAN OVERRIDE
Pressing the button marked
FAN
will change the fan mode between
AUTO
,
ON
and
SMART FAN
.
AUTO
:
Thermostat starts fan
when there is a demand for either
heating or cooling. Note: If the installer has selected "Fossil Fuel Aux.
Heat", the fan is controlled by the warm air heater whenever there is
a call for auxiliary heating.
ON
:
Fan runs continuously.
SMART FAN
:
Fan runs continuously during events 1-6 unless a
programmed "Off" is encountered, but reverts to Auto mode during
event 6-1. When in "Smart Fan" mode, the bar on the display adjacent
to FAN ON will flash.
SELECTING EMERGENCY HEAT MODE
The EM HEAT button beneath the
flap can be used to select the
"Emergency Heat" mode. When
selected the heat pump will be turned
off and all heating will be provided
by the auxiliary heating stage. An
"E" in the display will flash until the
unit is returned to normal operation (See Fig.11). To restore the
system to normal heat pump operation press the EM HEAT button,
then SEL button three times to return the unit to the AUTO mode.
BATTERY MAINTENANCE
It is recommended that high quality alkaline batteries are used.
New batteries will provide the power for switching the outputs on and
off for approximately 2 years. When the batteries' voltage drops to the
minimum level needed to maintain operation, a battery symbol will
blink in the display (See Fig.12). When this symbol appears both
batteries should be replaced with high quality alkaline cells. Operation
will continue normally until the 15th midnight after the symbol started
blinking and then the unit will switch off all outputs and shut down with
just the time and the blinking battery displayed. While the battery
symbol is still blinking, the old batteries may be removed and new
batteries placed in the sleeve and inserted
within one minute.
Internal circuitry will maintain the user set program during this period.
Fig. 12.
Blinking battery symbol,
change batteries.
AUTO
HEAT
COOL
OFF
AUTO
ON
20.0°c 15.0°c
13:59
Fig. 8.
Temperature raised - heating
system & fan running.
AUTO
HEAT
COOL
OFF
AUTO
ON
23.3°c 18.3°c
AUTO
HEAT
COOL
OFF
AUTO
ON
25.0°C 20.0°C
°C
20.0
TIME OR TEMPERATURE DISPLAY
The default display in RUN mode shows the time of day. This may be
changed to display the actual temperature being sensed by pressing
both
COPY
and
NEXT
buttons simultaneously. Return to time display
by pressing them simultaneously again.
THERMOSTAT MODE
The HP75 can be converted to control either heating or cooling, (not
both), at a constant user selected temperature by selecting "Thermostat
mode". To do this, press and hold down both
buttons until the
display changes to that shown in fig. 6. When entering thermostat
mode the default setting is heating only, with a default temperature of
8°C (46°F), this can be changed as required by pressing either or
until the require temperature is displayed.
To control at a constant cooling temperature (heat off), press the 'SEL'
button to select 'COOL', the temperature will be shown as 28°C (82°F)
(fig. 6a) use the and buttons to select the required temperature.
When in thermostat mode if "OFF" is selected by means of the
button, both heating and cooling are turned off.
To return to normal programmed operation, press and hold both and .
FROST PROTECTION MODE
While in thermostat mode the HP75 may be set to guard against
possible frost damage in areas where the unit (or its remote sensor)
is installed. The heating control temperature may be set to a suitable
level using the
and pressed simultaneously.
VACATION MODE - HEATING ONLY OR COOLING ONLY
While in thermostat mode with either HEAT or COOL selected, pressing
the
DAY
button will activate the holiday mode. The display will change
to that shown in Fig. 7 or Fig. 7a with a number indicating the default
holiday period of 00 days. Use the + or - buttons to set the number of
days required, in the range 1-99 days. If the number of days is left at 00
then the unit will return to normal at event 1 the following day. When the
selected number of days have elapsed the unit will automatically return
to normal, controlling temperatures to the set programme.
Control may also be restored to normal before all days have elapsed
by pressing the and simultaneously.
USER OVERRIDES
While the unit is operating normally in RUN mode the following
overrides are available:
TEMPERATURE SETTING OVERRIDE
Press to increase or to decrease the current set temperatures.
Each press will change the temperature settings by 0.5°C (or 1°F). To
make larger changes press the button and hold it down. The
temperatures can be raised until the cooling setpoint reaches 36°C
(97°F) or lowered until the heating setpoint reaches 5°C (41°F). Note
that the programmed dead band between the heating and cooling
temperatures is maintained while the override is being used. (Fig. 8 &
Fig.9).
AUTO
HEAT
COOL
OFF
AUTO
ON
AUTO
HEAT
COOL
OFF
AUTO
ON
20.0°c
25.0°c
13:54
13:54
AUTO
HEAT
COOL
OFF
AUTO
ON
AUTO
HEAT
COOL
OFF
AUTO
ON
5.0°c
5.0°c
13:54
13:54
Fig. 10
AUTO
HEAT
COOL
OFF
AUTO
ON
E
20.0°c
13:54
Fig.11
Part No: 31181 Iss.3. 06/01
Danfoss Randall Ltd
Ampthill Road
Bedford MK42 9ER
Tel: (01234) 364621 Fax: (01234) 219705
Email: [email protected]
Website: www.danfoss-randall.co.uk
Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This
also applies to products already on order provided that such alterations can be made without subsequent changes being necessary in specifications already agreed.
Fig. 5.
Temperature Display. (Space
temperature is below the set
temperature, so the heating system
and fan are operating).
