Slant/Fin EM-10 Service Manual - Manual (Page 8)

FIRE DELAY (Burner symbol DLY)
Does NOT apply to electric boiler operation.
The Fire Delay is the delay time that may occur between
the time that the control closes the Stage 1 contact and
when the burner fires. This delay is usually the result of a
burner pre-purge or other forms of time delay built into the
burner’s safety circuits.
BOILER TARGET TEMPERATURE (BOIL TARGET)
The boiler target temperature is determined from the
mode of operation and the type of demand applied. The
control displays the temperature that it is currently trying to
maintain at the operating sensor as BOIL TARGET in the
View menu. The operating sensor for modes 1, 3, 4 and
6 is the boiler outlet sensor, and the operating sensor for
modes 2, 5 and 7 is the boiler supply sensor. If the control
does not presently have a requirement for heat, it displays
“– – – ” in the LCD. There is no boiler target temperature
generated in Mode 8.
BOILER MINIMUM (BOIL MIN)
The BOIL MIN setting is the lowest water temperature that
the control is allowed to use as a boiler target temperature.
During mild conditions, if the control calculates a boiler
target temperature that is below the BOIL MIN setting, the
boiler target temperature is adjusted to at least the BOIL
MIN setting. During this condition, if the boiler is operating,
the MIN segment turns on in the LCD while the boiler
target temperature or boiler operating sensor temperature
is viewed. If the installed boiler is designed for condensing
or low temperature operation, set the BOIL MIN adjustment
to OFF.
BOILER MAXIMUM (BOIL MAX)
The BOIL MAX setting is the highest water temperature that
the control is allowed to use as a boiler target
temperature. If the control does target BOIL MAX, and the
temperature at the boiler outlet sensor is near the BOIL MAX
temperature, the MAX segment turns on in the LCD while
the boiler target, boiler inlet, boiler outlet or boiler supply
temperature is viewed.
BOILER OUTLET MAXIMUM
The BOIL OUT MAX setting determines the highest water
temperature allowed at the boiler outlet sensor. The boiler
stages are immediately shut off once the water temperature
exceeds the BOIL OUT MAX setting at the boiler
outlet sensor location.
BOILER PUMP OPERATION ( )
The boiler pump contact operates when:
• A heat demand is present and parallel piping (Mode 1,
3, 4, 6) is used. Parallel piping requires the boiler pump
to operate even while the boiler is off in order to provide
heat to the system.
• While the boiler is on and primary / secondary piping
(Mode 2, 5, 7) is used. Primary / secondary piping
reduces standby losses by isolating the boiler from the
system while the boiler is off.
• During external direct drive operation (Mode 8), the boiler
pump contact closes whenever there is an internal heat
demand.
• After the boiler shuts off the boiler pump remains on to
purge heat from the boiler to the system.
BOILER PUMP PURGE ( DLY)
After the boiler is shut off, the control continues to operate
the boiler pump for a period of time. The length of time that
the boiler pump continues to run is based on the Pump
DLY setting. Once the boiler turns off, the control keeps
the boiler pump running for the time selected. This setting
allows purging of any excess heat out of the boiler after the
boiler is shut off. This also helps to prevent the water in the
boiler from flashing into steam after the boiler is shut off.
When Pump DLY is set to OFF, there is no purging. When
Pump DLY is set to ON, the pump runs continuously. When
on is selected and the control is configured for outdoor reset,
the pump continues to run even during Warm Weather Shut
PUMP EXERCISING
If the boiler pump has not operated at least once every 70
hours, the control turns on the output for 10 seconds. This
minimizes the possibility of the pump seizing during a long
period of inactivity.
ALERT
The control closes the alert contact whenever an error
message is present.
8 EM-40-SM Service Manual
Partial Outdoor Reset
Decreasing Outdoor Air Temperature
Increasing Water Temperature
B oil MAX Boil MAX
B oil MIN Boil MIN
WWS D WWSD
OUTDR DS G N
B oil DS G N
B oil S TAR T
OUTDR S TAR T