Weil-McLain Evergreen EVG 220 Manual page 44

®
gas
System piping -
See Advanced Manual for Multiple Boiler Systems
Circulator zoning –
(Shown with optional DHW piping)
See Figure 53.
1. This configuration is for circulator-zoned systems using a boiler
loop connected as a secondary circuit off of a primary system
loop. Systems zoned with circulators must pipe the boiler loop as
a secondary circuit as show.
2. Install a separate circulator (supplied by installer) for each zone
capable of delivering the proper flow and head as shown.
3. The flow/check valve shown on the boiler outlet piping prevents
gravity circulation in the boiler loop during DHW heating.
Use at least the MINIMUM pipe size shown in
Figure 47, page 39 on all boiler loop piping (connecting
boiler to and from the primary/secondary connection,
item 14). Use only primary/secondary piping as
shown. Failure to follow these guidelines could result
in system problems.
Expansion Tank required
1. Provide a system expansion tank following the guidelines on
page 42.
2. DO NOT use a closed-type tank if connecting to a water heater
that is equipped with an automatic vent.
Domestic Hot Water (DHW) tank, if used
1. DHW direct connection—Pipe from the near-boiler piping to the
DHW tank's boiler connections as shown.
2. DHW as zone— A DHW tank can be connected as a zone if a
DHW tank is NOT already connected to the boiler. See notices
on page 129 to ensure compliance with the 2007 Energy Act. See
Advanced Manual to configure Boiler Pump to run during DHW
demands and change TARGET MOD SENSOR to System Supply.
3. DHW Priority operation— Using Priority 1 for DHW (default) will
turn off lower priorities during DHW calls. The MAX ON TIME
setting can be adjusted to limit how long this occurs. Use Priority
2 or 3 for DHW if DHW priority is not desired.
Overriding the Outdoor Reset function by setting control
to DHW mode when system is intended for space heat-
ing may violate Section 303 of the 2007 Energy Act. See
page 129 for compliance information and exemptions.
Controlling the circulators
1. The control can control up to four circulators (boiler circulator
and three others). Refer to Field wiring, beginning on page 52, for
instructions on wiring to circulators.
LEGEND for Figure 53 and Figure 54, page 45
1 Evergreen boiler
2 Indirect Water Heater, if used
3 Relief valve, supplied with boiler, field piped — MUST
be piped to boiler supply connection — see page 41 for
information
4 Relief valve piping to drain — see page 41.
5 DHW circulator
6 Isolation valves
7 System circulator
8 Expansion tank, diaphragm type, if used
9 Air separator
10 Flow/check valves or spring check
11 Purge/drain valves
(one drain valve shipped loose with boiler)
12 Auto air vent
13 Zone valves
– 44 –
-
fired water boiler
Single Boiler Systems
primary/secondary
14 Primary/secondary connection (tees no more than 12
inches apart)
15 Expansion tank, closed type, if used (some chiller
systems may use a diaphragm-type expansion tank)
16 Water chiller
17 Check valve
18 Y-strainer
19 Balancing valve
20 Make-up water supply – Use applicable codes to deter-
mine if backflow preventers, pressure reducing valves,
and fill valves may be required
21 By-pass pressure regulator, Recommended for zone
valve systems unless other provision is made
22 High limit temperature control, when required by local
code or for a radiant system.
— 220/299/300/399 Boiler Manual
Figure 53
Circulator zoning plus optional DHW piping
MINIMUM
Boiler loop pipe size
Evergreen 220 1¼"
Evergreen 299/300, 399 1½"
See CAUTION at left.
2. The factory default settings are: all three inputs are set up
for Space Heating (
respective circulator output. For DHW Priority applications,
wire aquastat to Input 1 and assign to Priority 1. See Field wir-
ing instructions, beginning on page 52, for details.
3. For more than 3-zones, use Weil-McLain WMCR zone Circ
controller.
Note: This is a common legend for all piping diagrams, not
all items listed appear in every figure.
(continued)
Priority 2) . Each input correlates to its
23 DHW tank boiler water supply connection, when used
24 Zone circulator
25 DHW tank boiler water return connection, when used
26 Pressure/temperature gauge, supplied with boiler, field
piped
27 Heating circuits
28 Additional heating circuits, if any
29 Boiler circulator
30 Mixing device, if any
31 System supply and return sensors: Strap system sensors
to lines as shown, at least 6 pipe diameters (but no more
than 3 feet) from boiler connection tees.
32 Low Water Cut-off
Part number 550-100-131/0120