resideo Aquastat L7224U Manual Del Usuario página 9

Table 5. L7224/L7248 Controller Operating Sequence.
Action
Thermostat Circulator starts when water temperature is
calls for heat. above Low Limit setting (if applicable) or above
the Thermal Purge Temperature Limit (tPL) if
Thermal Purge is enabled. Boiler temperature
is checked. Burner starts when water
temperature is below High Limit setting minus
the differential or at or below the Thermal
Purge Temperature Limit (tPL) for cold start
boilers if the Thermal Purge Temperature Limit
is enabled. If tPL is enabled, the burner may
also start if the boiler temperature is cooling at
10 ºF or greater per minute or the Thermal
Purge Time Delay (tPt) has expired.
If Anti Short-Cycle Time is enabled, the burner
does not start until the set Anti Short-Cycle
Time between cycles expires after the previous
call for heat was satisfied.
Boiler Burner is turned off. Burner restarts when the
temperature water temperature drops below the High Limit
exceeds the setting minus the Differential. If Thermal Purge
High Limit. is enabled, the burner is turned on when either
the Thermal Purge Temperature Limit is
reached, the Thermal Purge Time Delay has
expired or the boiler temperature cooling rate
exceeds 10 ºF/minute.
Thermostat is Circulator and burner turn off.
satisfied.
Boiler Burner is turned on, Circulator is turned off.
temperature Burner stops when the water temperature
drops below exceeds the Low Limit setting. Power to Zc is
the Low Limit removed.
setting minus
the differential
(if applicable).
Error If an error condition is detected, all outputs
conditions except ZC are shut down. Burner is off. The
1-5. controller continues to function and restarts
when error is corrected.
During the error check sequence, the system
checks for drift in the sensor and corrosion in
the connections.
Error EnviraCOM communication is not available.
condition 6.
Error The controller has reset the High Limit, Low
condition 7. Limit and Differential Setting to a default setting
and will continue to run at those settings.
Performance of the system will be degraded.
Error If the error condition is detected, all outputs
condition 8. except ZC are shut down. Burner is off.The
controller continues to function and restarts
when all three user keys have been pressed
longer than 60 seconds.
Error System continues to run with no outdoor reset
condition 9*. functionality
Error System continues to run with outdoor reset
condition parameters enabled as programmed. Error
10*. cleared automatically.
Error System continues to run with boiler temp set to
condition 11*. High Limit.
* Error condition only available when the Outdoor Reset
Module is installed.
L7224U OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT
System Response
Table 6. L7224 Controller Operating Sequence with multi-
ple zones connected through the ZR terminal
Action
Zone Request (ZR) Boiler temperature is checked. Burner
terminal is connected starts when water temperature is below
to L1 (Zone calls for High Limit setting or at or below the
heat). Thermal Purge Temperature Limit (tPL) for
cold start boilers if the Thermal Purge
Temperature Limit is enabled. If tPL is
enabled, the burner may also start if the
boiler temperature is cooling at 10 ºF or
greater per minute or the Thermal Purge
Time Delay (tPt) has expired. Anti Short-
Cycle Time is applied, see Table 5.
Boiler temperature Burner is turned off. Burner restarts when
exceeds the High the water temperature drops below the
Limit. High Limit setting minus the Differential. If
Thermal Purge is enabled, the burner is
turned on when either the Thermal Purge
Temperature Limit is reached, the Thermal
Purge Time Delay has expired or the boiler
temperature cooling rate exceeds
10 ºF/minute.
Zone Request input is Burner turns off.
de-energized (Zones
are satisfied).
Boiler temperature Burner turns on and Zone Control is de-
drops below the Low energized. Burner turns off and Zone
Limit setting minus Control is re-energized when the water
the differential (if temperature exceeds the Low Limit setting.
applicable).
Table 7. Controller Operating Sequence with External Low
Limit device connected trough the ZR terminal.
Action
Zone Request (ZR)
terminal is connected
to L1 (External Low
Limit call for heat).
Boiler temperature
exceeds the High
Limit.
Zone Request input is
de-energized (External
Low Limit is satisfied).
Table 8. L7224 Controller Operating Sequence with Domes-
tic Hot Water connected trough the ZR terminal.
Action
Zone Request (ZR) terminal
is connected to L1
(Domestic Hot Water calls
for heat).
Boiler temperature exceeds
the High Limit.
Zone Request input is de-
energized (Domestic Hot
Water is satisfied).
9
®
CONTROLLER
System Response
System Response
Boiler temperature is checked. Burner
starts when water temperature is below
High Limit setting. Circulator turns off.
Burner is turned off. Burner restarts
when the water temperature drops
below the High Limit setting minus the
Differential.
Burner is turned off.
System Response
Boiler temperature is checked. Burner
starts when water temperature is
below High Limit setting.
Burner is turned off. Burner restarts
when the water temperature drops
below the High Limit setting minus
the Differential.
Burner is turned off.
69-1720EFS—13