11 commissioning – Grant Products HPAW155 User Manual
11.2 Setting the ATC Controller
The main purpose of the ATC controller
is to give an overall maximum
temperature control over the heat
pump. In contrast, the BTC controller
will give accurate control over both CH
and DHW temperatures, even if they
each have different target temperatures.
There are 3 main conditions the ATC
can be set in:
1. OFF – no signal to the heat pump,
irrespective of other heating
controls. THE HEAT PUMP WILL
NOT OPERATE IN THIS
2. Automatic (Sun Symbol) – The heat
pump is in a fully automatic
condition. Conditions such as
running, defrosting, frost protection
are all operative.
3. Stand-by (Triangle Symbol) - Only
basic functions are possible. Frost
protection and back up heater will
Press the ‘M’ button to switch between
‘Automatic’ and ‘Standby’ settings.
The ATC also has a series of fault
codes which will help in any fault
diagnosis, should an internal fault occur.
Refer to Section 13.3 for details.
Set the time function on the ATC using
the following procedure.
1. Press the ‘SET’ button twice. The
hour segments will flash. Using the
buttons to alter the hour
2. Press the ‘SET’ button again to set
the minutes Using the
3. Press the ‘SET’ button to confirm
4. The clock is now set.
Setting the ATC parameters:
The table shown on page 31 gives a list
of the parameters applicable to the
ATC. Please note that there are
parameters that MUST NOT be altered.
Changing these parameters will
adversely affect the efficiency of the
heat pump and will invalidate all
To alter a parameter, first press
you have reached the appropriate
function. To alter the setting, press the
‘SET’ button once, then use the
buttons to alter the value. Once set,
press the ‘SET’ button to exit back to
the function menu.
If no button is pressed for a period
of 20 seconds, the ATC will
automatically default back to normal
Figure 11-1: ATC display and buttons