Evergreen Control Operation; Control Features; Sequence Of Operation - Weil-McLain Evergreen 220 User Manual

™ GAS

Evergreen Control operation

Evergreen control setup
1. Set control parameters using the WIZARD option provided on initial
start-up or manually enter parameters using control menus (see
Figure 71, page 73 and following pages for information.)
2. See instructions beginning on page 66 for basic
systems and minimum settings required (using factory defaults).
3. This manual provides set-up information for a single boiler using
BASIC control setting options. See the EVG Advanced Manual for
single-boiler advanced settings and for all multiple boiler applica-
tions.
to set correctly could result in severe personal injury, death or substantial
property damage.
— You must ensure that the Evergreen control
is set for the proper water temperatures for the system. Excessive water
temperature can cause significant property damage in some applications.
that require lower temperature water (radiant slab circuits, for example)
as well as higher temperature circuits (DHW, finned tube baseboard,
etc.), it is recommended to protect low-temperature circuits with limit
controls that are wired to an Evergreen control external limit circuit.
Failure to provide regulation can result in substantial property damage.

Control features

❏ Single or multiple boiler control (with lead boiler rotation).
❏ Graphic and robust text display for ease of operation monitoring and
troubleshooting.
❏ Three programmable priority assignments for up to three heat inputs.
❏ Preset operating parameters for typical heating systems, including target
temperatures, reset curves and circulator assignments.
❏ Integral outdoor reset option, with reset curves matched to the system
type selected.
❏ ModBus communications for external communication and monitoring.
❏ 0-10VDC input modulation or remote target input.
❏ Four pump outputs, including 1 boiler pump output.
❏ Additional heat demand operation to call a second heat source to help
supply the energy required for heating.
❏ Advanced PI response to anticipate system needs.
❏ Flue temperature modifier to target temperature.
❏ Modulation based on flue sensor and boiler/system supply/return
sensors.
❏ Integral low water protection by monitoring heat exchanger temp.
❏ Dual temperature sensors on boiler outlet and flue, providing redun-
dant protection.
❏ Boiler is shipped with an outdoor sensor and strap on system supply
and return sensors.
❏ Blower speed modulation to control boiler firing rate.
❏ Alarm relay on error/fault for use with an audible safety.

Sequence of operation

1. Figure 64 is a summary of the operating sequence for the Evergreen
control.
The statuses shown appear in the display as the Evergreen control
cycles the boiler. See Figure 68, page 65 for screen shots.
The display will flash red if a problem has been detected.
Part number 550-100-131/0715
-
FIRED WATER BOILER
— If the heating system includes circuits
— Boiler Manual
Failure
Control sequence of operation
(also see Figure 68, page 65)
Check the boiler model listed on the power-up
screen. If it is not correct, turn off the boiler.
See page 74 for instructions to change setting.
When power is turned on, the screen lists sen-
sors that are detected. If any sensor is not listed,
make sure it is connected correctly. Turn off
power and restart.
Standby - no calls for heat.
Toggles through no dots, 1 dot, 2 dots, then 3
dots while in standby (wrench symbol will show
instead if maintenance is needed).
Call for heat detected.
Display on with BLUE light (space heating) or
PURPLE light (DHW).
Start min/max timers if more than one system
is calling - highest priority starts first.
Start circulators for this priority setup based
upon settings.
Calculate target temp — If sensor temp is below
target temp, begin firing sequence.
Blower to ignition speed for prepurge.
After prepurge times out, begin ignition cycle.
Activate gas valve and ignition spark.
Continue ignition spark for ignition period.
Turn off spark and use electrode to check for
flame signal.
Flame detected.
Release boiler to modulation.
NOTE: If flame is not detected, the gas valve is
turned off, blower turns on (postpurge), and
control starts cycle again. After 5 failures, the
control waits 60 minutes, then tries again.
If priority timer times out, switch to next priority
and start priority timer.
If demand satisfied, go to postpurge.
Flame detected.
Release boiler to modulation.
NOTE: If flame is not detected, the gas valve is
turned off, blower turns on (postpurge), and
control starts cycle again. After 5 failures, the
control waits 60 minutes, then tries again.
If priority timer times out, switch to next priority
and start priority timer.
If demand satisfied, go to postpurge.
Demand satisfied (temperature reaches target
temperature or limit setting).
Gas valve off.
Blower to ignition speed for postpurge.
Return to standby after purge.
Display turns BLUE, toggling between graphic
screen and maintenance screen (occurs if main-
tenance schedule timer times out).
Will show during standby only.
Boiler operates as normal.
Display turns RED due to error or limit event.
Flashing display means lockout condition.
Warm weather shut down - the boiler will not
be allowed to fire on space heating if the outside
temperature is greater than the WWSD setting.
DHW operation is not affected by WWSD.
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