Honeywell Sola Controller Start Sequence - Ace Heating Solutions Atlas A050 Operating And Maintenance Manual

Lockout
A Lockout code is displayed in the numerical part of the display when a Lockout state is received. When the Reset button
is pressed, the Honeywell Sola Controller is forced to leave the Lockout state.
Communication Timeout
Alert code 981 is displayed as Basic Panel internal Alert when the Honeywell Sola Controller repeatedly does not respond
to message queries sent by the Basic Panel.

3-8 Honeywell Sola Controller Start Sequence

When the Panel Burner Cutoff switch is set to the ON position, Honeywell Sola Controller checks all prepurge safety
switches to ensure they are closed.
NOTE: Hold code along with Hold icon will be displayed on the Basic Panel when unit is in Hold state. Refer to
APPENDIX A – TROUBLESHOOTING AND HOLD/LOCKOUT CODE for help.
Standard Interlock switches include:
x
Burner Cutoff Switch
x
High Gas Pressure Switch (if supplied with unit, standard on A300)
x
Low Gas Pressure Switch (if supplied with unit, standard on A300)
x
Blocked Drain Switch
x
Water Flow Switch
x
Air Flow Switch
Additional Interlock terminals supplied for field integration include:
x
Recycle Interlock: Recycle interlocks typically include all the limits that cause a burner to hold or recycle. The
burner will not fire if the recycle interlock input is open. If recycle interlock is opened during a burner run cycle, the
system will return to standby.
x
Delayed/Lockout Interlock: Delayed/Lockout interlocks must close within some seconds after demand is present
during prepurge. This limit will cause a burner to lockout if the interlock opens during a run cycle on A300 only.
NOTE: Additional Interlocks terminals supplied for field integration are located in the Field Wiring Box placed in the rear of
the unit. Remove the jumper installed from the factory to enable interlocks.
When all of the above interlock switches, including Pre-Ignition and Recycle Interlocks are closed, only the light on the
Burner Cutoff switch would be on at this time and the boiler will be in the Standby mode.
When there is a demand for heat from Central Heating or DHW, following events will occur:
x
Appropriate pump contact is closed to energize the boiler circulation pump.
x
Blower relay energizes and turns on the Combustion Blower and the Auxiliary Blower.
x
Combustion Air Flow switch close and combustion blower drives to prepurge speed.
x
Prepurge rate is verified with blower feedback signal and initiates 7 second prepurge.
x
After prepurge is completed, Combustion blower drives to light off rate.
x
After light off rate is verified, 10 second PFEP (Pilot Flame Establishment Period) is initiated.
x
During first half of PFEP, pilot valve solenoid and spark transformer are both energized.
x
Spark transformer is de energized during second half of PFEP and only pilot valve is energized.
x
When pilot flame is proofed, 4 second MFEP (Main Flame Establishment Period) is initiated.
x
During MFEP, Main Safety Shutoff Valve and pilot valve solenoids are energized and firing rate is held at light off
rate.
x
After MFEP, pilot valve is de energized and main burner modulates its firing rate according to load demand.
When desired temperature is achieved, following events will occur:
x
Main Safety Shutoff Valves are de-energized and Combustion Blower drives to postpurge rate and initiates 15
second postpurge.
x
After postpurge, boiler will be in the Standby mode.
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