Sequence Of Operation; Boiler Circulator; Outdoor Reset Operation - Weil-McLain Evergreen 220 Advanced Manual

CONDENSING GAS BOILER
™
Evergreen Control
EVG control Priorities & Input/Outputs
For heating installations with multiple systems, the EVG
control uses
PRIORITIES
tion of the systems.
The control's MAX and MIN time settings determine the
maximum and minimum times a system will be oper-
ated before being turned off to allow another system to
operate.
A typical example is DHW priority — heat demand from
the DHW system is given preference over space heating
if assigned to Priority 1.
Each PRIORITY has its own set of operating parameters.
The control prompts the user to select the system type
(finned tube baseboard, DHW, etc.) and is factory
programmed with parameters suited to each of these
system types.
The user can also choose CUSTOM to create a system
type.
The EVG control provides up to three
boiler applications and up to four priorities for network
boiler applications. The order of operation is:
Single boilers: PRIORITY 1, PRIORITY 2, PRIORITY 3.
Network boilers: LOCAL PRIORITY 1, NETWORK
PRIORITY 1, NETWORK PRIORITY 2, LOCAL PRI-
ORITY 2.
For each boiler in a network, this provides up to two
priorities, used for heating systems piped directly
LOCAL
to the boiler, such as DHW tanks.
priorities are used for heating systems con-
NETWORK
nected in the primary heating loop and supplied by the
boiler network.
Each boiler has three
INPUT/OUTPUT
PUT 1, 2 and 3.
Control setup prompts the user to assign each of these
I/O pairs to a PRIORITY. The EVG control then knows
which system (priority) to operate when any input as-
signed to that priority receives a call for heat.
The EVG controls respond to heat calls based on the
order of the assigned priorities and the timings set for
each priority's operation.

Boiler circulator

The boiler circulator is shipped loose with the boiler for
field installation.
The 120 VAC power output to the boiler circulator is provided
by a relay located on the boiler's Pump/Communications
Board. For each of the priorities, the control can be setup to
run the boiler pump or to leave it off. It is recommended to
set Boiler Circulator to OFF for directly piped DHW systems
with its own circulator.
The boiler circulator must be installed and con-
nected. Flow through the boiler must be provided
during all times of operation. Failure to do so can
result in severe personal injury, death or substantial
property damage.
– 4 –
— ADVANCED mode
to determine the order of opera-
for single
PRIORITIES
pairs (INPUT/OUT-
— Advanced Manual
Multiple boiler operation
The Evergreen boiler has an auto detection feature for mul-
tiple boiler networks. The Master will automatically detect
the presence of the other boilers wired to the network.
There will be a 30 second to 1 minute period until the Master
may see the shadow boilers.
Each shadow boiler must be assigned a network address, from
2 through 8. The address for each boiler must be unique,
NOT selected for any other boiler.
Afterwards, the Master will build a network based on the
communications shared. If a boiler loses communication, the
Master will automatically re-assign the lost boiler to where
it was before once it is back on the network.
When network inputs turn on, the Master boiler will enter
the Network Modulation routine.
Using system sensors, the Master will modulate the entire
network to meet the energy requirements of Network Priority
1 and Network Priority 2 inputs when they are on.
When a Local Priority input becomes active (switch closes),
modulation for that input is not controlled by the Master,
but instead is left to that local boiler using its own local Heat
Exchanger Inlet and Outlet sensors.
Each of the three (3) inputs on the Master or any of the
Shadow boilers can be assigned as Network Priority 1 or 2
or assigned as Local Priority 1 or 2. Network Priority settings
are common across all the boilers. These Network Priority
settings can only be adjusted from the Master boiler.

Sequence of operation

Figure 19, page 36 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.
The display will display red (solid or flashing) if a prob-
lem has been detected.

Outdoor reset operation

1. Calculates target temperature for space heating zones based
on outdoor temperature.
2. For an explanation of the target temperatures and associated
outdoor temperatures, see Figure 1, page 5.
3. The temperature settings discussed below are accessed in
the priority menu for the applicable system. For detailed
explanations of the priority menus, see Figure 28, page 46.
SUPPLY MAX
1. Set SUPPLY MAX to the required supply water temperature
for the system at design maximum heat loss (typically 180°F
for finned tube baseboard on new installations).
(continued)
Part number 550-100-160/0715