Circulator Zoning - Primary/Secondary - Weil-McLain Evergreen EVG 70 Manual

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Primary/Secondary System piping
Circulator zoning –
(Shown with optional DHW piping)
See Figure 54 .
1. This confi guration 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 fl ow and head as
shown.
Expansion Tank required
1. Provide a system expansion tank following the guidelines
on page 45 or 46 .
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 139 to ensure compliance with the 2007
Energy Act. See Advanced Manual to confi gure 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 139 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 54 , for instructions on wiring to circulators.
2. The factory default settings are: all three inputs are set up
for Space Heating (Priority
respective circulator output. For DHW Priority applications,
wire aquastat to Input 1 and assign to Priority 1. See Field
wiring instructions, beginning on page 54 , for details.
LEGEND for Figure 54 and Figure 55
1 Evergreen ® boiler
2 Indirect Water Heater, if used
3 Relief valve, supplied with boiler, fi eld piped — MUST
be piped to boiler supply connection — see page 14 for
information
4 Relief valve piping to drain — see page 48
5 DHW circulator
6 Isolation valves
7 System circulator
8 Expansion tank, diaphragm type, if used
9 Air separator
10 Flow/check valves
11 Purge/drain valves
(one drain valve shipped loose with boiler)
50
as-fired water boiler —
primary/secondary
2). Each input correlates to its
12 Auto air vent
13 Zone valves
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
determine if backfl ow preventers, pressure reducing
valves, and fi ll valves may be required
70/110/155
(continued)
Figure 54 Circulator zoning plus optional DHW piping
3. For more than 3-zones, use Weil-McLain WMZV zone valve
controller.
Connect zone valve end switches to Priority 2 input.
Connect system circulator to Circ. 2 output.
Use isolation relays if connecting 3-wire zone valve
end switches to the input.
Note: This is a common legend for all piping diagrams.
Not all items listed appear in every fi gure.
21 By-pass pressure regulator, REQUIRED for zone valve
systems unless other provision is made
22 High limit temperature control (If used)
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, fi eld
piped
27 Heating circuits
28 Additional heating circuits, if any
29 Boiler circulator, if any
30 Mixing valve, if any
31 Low Water Cut-Off
Boiler Manual
Part number 550-100-191/0917