LP-446-r4 Rev. 10.12.16
20
The piping will not support the weight of the circulators. Refer to the circulator manufacturer’s instructions to properly support
the circulator. Failure to comply with these instructions could result in property damage, severe personal injury, or death.
An ASSE 1017 thermostatic mixing valve is recommended on all tanks if the hot water temperature leaving the tank is above
119
o
F. Failure to do so could result in substantial property damage, serious injury, or death.
Figure 9 - Two VWH Boilers with Storage Tank
FIGURE NOTES:
1. This drawing is meant to show
system piping concept only.
Installer is responsible for all
equipment & detailing required by
local codes.
2. Boiler circulator must be rated for
open loop application. Do not use
cast-iron circulators.
3. Boiler circulator(s) operate
continuously.
4. The minimum pipe size for
connecting a storage tank is 1 1/2”.
5. The minimum pipe size for
connecting a boiler is 2”. When
sizing and installing a multiple
boiler system, see Multiple Boiler
Manifold Piping Chart, this manual.
6. All pumps are shown with
isolation flanges or full port ball
valves for isolation. The alternative
is standard flanges with full port ball
valves and a separate flow check
valve.
7. Install a minimum of 12 diameters
of straight pipe upstream of all
circulators and check valves.
8. Install vacuum relief valve
in accordance with local code
requirements.
9. Multiple boilers and storage
tanks shall be installed with reverse
return piping (as shown).
10. Expansion tank must be rated
for use with potable water.
11. Use either indirect/tank sensor
or system/pipe sensor mounted on
common return to the boiler.
12. Wire the tank or system/pipe
sensor to the DHW sensor terminals
input on the follower boiler
addressed as #1.
13. Wire the tank or system / pipe
sensor connected to the DHW
sensor terminals on the follower
boiler addressed as #1.
14. The system / pipe sensor must
be placed on common piping to the
tank as close to the tank as possible.
15. The system / pipe sensor is wired
to the system sensor terminals on
the master boiler.
16. The minimum storage tank size for a 500VWH is 119 gallons. The minimum storage tank size for a 700/850VWH is 175 gallons.
Figure 10 - Two Stacked VWH Boilers with Storage Tank
Summary of Contents for MODCON500
Page 35: ...LP 446 r4 Rev 10 12 16 35 Figure 29 Cascade Master and FollowerWiring...
Page 57: ...LP 446 r4 Rev 10 12 16 57 Figure 35 500 Model Combustion System Replacement Parts...
Page 58: ...LP 446 r4 Rev 10 12 16 58 Figure 36 700 850 Models Combustion System Replacement Parts...
Page 60: ...LP 446 r4 Rev 10 12 16 60 Figure 38 Cabinet Replacement Parts All Models...