Weil-McLain Evergreen EVG 220 Manual page 45

®
gas
System piping -
See Advanced Manual for Multiple Boiler Systems
Circulator zoning – Multiple
temperature zones with
secondary
(Shown with optional DHW piping)
See Figure 54.
1. This configuration is for circulator-zoned systems with
high- and low-temperature heating zones 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 shown.
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 pri-
mary/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.
System setup and settings
1. Hi-temp emitters may be baseboards, radiators, fan coils,
or heat exchangers.
2. Add a mixing device (Figure 54, item 30) to help ensure
supply water temperature will not exceed the maximum
allowable for the radiant system.
3. Heating zone supply water temperature settings should
be selected for the hi-temp zones. The mixing device
regulates supply temperature to the lower-temp zones.
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 heating 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 cir-
culator and three others). Refer to Field wiring, beginning
on page 52, for instructions on wiring to circulators.
Part number 550-100-131/0120
-
fired water boiler
Single Boiler Systems
primary/
— 220/299/300/399 Boiler Manual
Figure 54 Circulator zoning with high- and low-temperature
heating zones
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
Priority 2)
Heating ( . Each input correlates to its respective circulator
output. For DHW Priority applications, wire aquastat to Input 1 and as-
sign to Priority 1. See Field wiring instructions, beginning on page 52,
for details.
3. For more than 3-zones, use Weil-McLain WMCR zone Circ
controller.
4. The Control can operate the Hi-Temp Zones and Low-Temp Zones
at the same time when the corresponding inputs are set to the same
priority (default: Priority 2). A mixing device must be used in this ap-
plication to guarantee the proper temperature to the Low-Temp Zones.
Two different Priorities can also be used in this application (such as
Priority 2 and Priority 3). One priority used for the Hi-Temp Zones
and the other used for the Low-Temp Zones. This will allow the boiler
to run at lower temperatures while satisfying the Low-Temp Zones
thus increasing the boilers efficiency. Proper safety measures should
be takes to ensure safe water temperatures to the Low-Temp Zones
such as a Mixing device and/or a High Limit Temperature Control.
The Control can only satisfy one priority at a time. Please set min and
max on timers for each priority for optimal performance.
(continued)
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