Weil-McLain ULTRA299-S4 Manual page 55

S 4
®
ERIES GAS
Install water piping — advanced
Chilled water systems
1. Install boiler so that chilled medium is piped in parallel with
the heating boiler. Use appropriate valves to prevent chilled
medium from entering boiler. See Figure 51 for typical instal-
lation of balancing valve and check valve.
Use the
ure 51 on all boiler loop piping (connecting boiler
to and from the primary/secondary connection,
item 21).
Failure to follow these guidelines could
result in system problems.
2. The space heating system may be zoned with circulators if
a separate circulator is supplied for the chilled water loop.
If antifreeze is used in the system, consider the ef-
fects of antifreeze on circulator sizing and DHW
performance. Some local codes may require double-
wall DHW heat exchanger design.
Chilled medium, if used, is piped in parallel with
heating boiler as shown in Figure 51 . Use appropri-
ate valves to prevent chilled medium from entering
boiler.
If boiler is connected to heating coils located in
air handling units where they can be exposed to
refrigerated air, use fl ow control valves or other
automatic means to prevent gravity circulation
during cooling cycle.
By default, the U-Control Module turns off space
heating during DHW heating (if DHW input is
priority 1). The boiler circulator will turn off, pre-
venting hot water from circulating to the system
(optional timeout setting can be used to override).
The fl ow/check valve shown on the boiler outlet
piping prevents gravity circulation in the boiler
loop during DHW heating.
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 137 for compliance information and exemptions.
3. Controlling the circulators
a. The U-Control can control up to three circulators (boiler
circulator and two others). Refer to Field wiring, begin-
ning on page 30 , for instructions on wiring to circulators.
1 Ultra boiler
2 Indirect water heater (DHW), if used
3 Boiler relief valve (see page 9 for piping details)
4 Relief valve discharge piping (see page 9 for details)
5 DHW circulator (see page 56 for suggested sizing)
6 Isolation valves
7 System circulator (see information above for wiring)
8 Diaphragm (or bladder) type expansion tank (see page 56 for piping of
closed-type expansion tank, if used)
9 Air separator [with automatic air vent only on systems using diaphragm
(or bladder) type expansion tank]
10 Flow/check valves
11 Purge/drain valves
12 Boiler circulator
13 Zone valves, typical
15 Closed-type expansion tank
Part number 550-100-400/0717
-
FIRED WATER BOILER
pipe size shown in Fig-
Legend —
— Boiler Manual
(continued)
Chilled water system plus optional DHW
piping
Boiler loop pipe size
Ultra-80, 105
1"
Ultra-155, 230
1¼"
Ultra-299/310,
1½"
399
See CAUTION at left.
b. The factory default settings are: DHW circulator as
Circulator 1, boiler circulator as Circulator 2. See Field
wiring instructions, beginning on page 30 , for details.
Figure 51
16 Water chiller
17 Check valve
18 Strainer
19 Balancing valve
20 Make-up water supply
21 Primary/secondary connection (tees no more than 12 inches apart)
23 DHW supply/return
24 Strap system supply and return sensors to lines as shown, at least 6 pipe
diameters (but no more than 3 feet) from boiler connection tees.
25 Systems using high-head pumps may require a bypass pressure regulator
to prevent damage to control valves.
26 Temperature/Pressure gauge
27 DHW relief valve, if used
Items supplied with boiler
Items supplied by others
55