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© 2010 D 156 - 06/10
Display
Setpoint Operation
▼
POINTER
Displays the control operation as
indicated by the text.
HEAT
HEAT RELAY
Displays when the HEAT relay is
closed.
°
°F°
°C
°F, °C
Units of measurement
PRGM
PROGRAM MENU
Program the control settings.
The Difference Setpoint Control 156 has two control points;
heat source and storage. The heat source could be a solar
collector or wood boiler while the heat storage is typically
a storage tank. The control is looking at the temperature
difference (ΔT) between the source and storage to determine
when to close the relay and start the heat transfer. The
setpoint operation that follows will explain the on and off
points of the relay.
ΔT
Source
Maximum
Minimum
Storage
ΔT • hours
Diff’l
Item
Number Field
Displays the current value
of the selected item
Item Field
Displays the current
item selected.
Menu Field
Displays the
current menu
Buttons
Selects Menus, Items
and adjusts settings
Heat
Source
Heat
Storage
Pump
Storage
Sensor
Source
Sensor
Sequence of Operation
Symbol Description
When the Difference Setpoint Control 156 is powered up,
all segments are displayed in the LCD for 2 seconds, and
then the type number is displayed for 2 seconds. Next,
the software version is displayed for 2 seconds. Finally,
the control enters into the normal operating mode and by
default the LCD displays the current ΔT temperature.
Powering Up the Control
Status Field
Displays the current
status of the relay.
