TriangleTube 399 Solo - Manual (Page 22)

Boiler Piping
Additional Limit Control
If a separate LWCO device is required by cer-
tain local jurisdictions or when the boiler is
installed above the system piping, the follow-
ing guidelines must be followed:
- The LWCO device must be designed
for water installations, electrode probe-
type is recommended.
- The LWCO device must be installed in
a tee connection on the boiler supply
piping above the boiler.
- Wiring of the LWCO device to the
PRESTIGE Solo is done directly onto
the 24V terminal strip, reference Fig.
20 page 32 for available terminals for
an external limit (manual or auto reset).
If the installation is to comply with ASME or
Canadian requirements, an additional high
temperature limit may be needed. Consult
local code requirements to determine compli-
ance. The limit should be installed as follows:
- Install the limit in the boiler supply pip-
ing between the boiler and any isolation
valve.
- Maximum set point for the limit is
194ºF.
- For wiring of the limit reference Fig. 20,
page 32, using the external limit/manual
reset terminals on the 24V terminal strip.
This will provide a "hard" lockout
requiring a manual reset of the control.
Backflow Preventer
- Use a backflow preventer valve in the
make-up water supply to the unit as
required by local codes.
Boiler System Piping Applications
It is recommended on all piping applica-
tions to utilize a primary/secondary pip-
ing arrangement as a means to provide
freeze protection of the boiler, which is an
integral function of the boiler control.
Maintain the minimum boiler flow rate,
see Graphs 2 through 5 on pages 72 & 73.
For other piping arrangements, consult
the Engineering Department at Triangle
Tube or consult other approved/recog-
nized design arrangements.
On piping applications utilizing a single
zone or other recognized piping design
arrangements, it is recommended that the
installer uses flow/check valves with
weighted seats at or near the appliance to
prevent gravity circulation.
Expansion Tank and Makeup Water
Ensure the expansion tank is properly sized for
the boiler volume (3 gallons [12 L] for the
PRESTIGE Solo 60, 5 gallons [19 L] for the
PRESTIGE Solo 175/250, 7 gallons [26 L] for
PRESTIGE Solo 399) and the system volume
and temperature.
Undersized expansion tanks will cause
system water to be lost through the pres-
sure relief valve and cause additional
makeup water to be added to the system.
Eventual boiler heat exchanger failure
can result due to this excessive makeup
water addition.
CAUTION
BEST PRACTICE
BEST PRACTICE
16