DORCHESTER DR-FC 25, Installation, Commissioning And Maintenance Instructions

Page: 69 / 98

Introduction
Instruction Manual DR-FC 69
is
9 Service program
9.1 Introduction
The service program is used by the installer or service and maintenance
engineer for:
•
Setting the hysteresis ;
• Displaying the error history ;
• Displaying the water heater history ;
• Display the selected water heater ;
• Setting the pump on/off ;
• Setting the service interval ;
• Setting the display contrast ;
• Setting the backlight time ;
• Setting the display scroll speed .
These sub-menus are briefly described in the following paragraphs. If you are
not familiar in general with how to use the displays and menus, first read chapter
’5 The control panel’ .
n
Remark
The notation convention for the service menu is identical to that described
in paragraph
’8.2 Notational convention for menu-related instructions’ . The
difference is, you use
S
to bring up the service program, instead of
B
which brings up the main menu.
9.2 Setting the
hysteresis
If the preset temperature (SETPOINT) is higher than the current water
temperature, then the water heater might
not immediately start the heating
cycle (see chapter ’7.4 The water heater’s heating cycle’ ). To prevent
excessively frequent switching on and off, a there is a heating margin. We refer
to this margin as the hysteresis. The standard setting for this margin is 2°C. The
heating cycle starts if the water temperature drops to 2°C below the SETPOINT
and ends when the water reaches 2°C above the SETPOINT.
Set the hysteresis via:
•
S
:
HYSTERESE UP
Figure 9.2 shows an example.
Set the hysteresis via
•
S
:
HYSTERESE DOWN
9.3 Displaying the error
history
Display the error history via:
•
S
:
HISTORIE OF ERRORS
The controller will display an overview of ‘Blocking errors’ and ‘Lock out errors’.
In both cases, note that the control panel reserves 15 lines for the last 15 error
messages. If there are less than 15 error messages, then an ellipsis (...) is
displayed. The display first shows the ‘Blocking errors’. When
E
is
pressed, the ‘Lock out Errors’ are then displayed.
SERVICE MENU
»HYSTERESE
^ HISTORIE OF ERRORS
È APPLIANCE HISTORY
SELECT APPLIANCE
PUMP RELAY
SERVICE INTERVAL
CONTRAST DISPLAY
TIME BACKLIGHT
SCROLLSPEED
Figure 9.1 Service program
HYSTERESE UP »3ÉC
Figure 9.2 Heating cycle upper
limit
is