Prestige Prestige Solo 175, Руководство по установке и обслуживанию

Страница: 22 / 105

Boiler Piping
Low Water Cutoff Device
- The PRESTIGE Solo is equipped with a fac-
tory installed pressure switch type Low Water
Cut Off device.
- The minimum operating system pressure
allowable with this device is 10 psig.
- Check local codes if a Low Water Cutoff
Device is required. If so, determine if this
device meets the requirements of the local
codes.
The PRESTIGE Solo control system also
senses the system water temperatures
entering and exiting the heat exchanger
to provide protection against low water
conditions Where local codes and juris-
diction do not accept a pressure device
for low water protection, the jurisdic-
tions may accept these PRESTIGE Solo
integral control functions as a means of
providing low water protection.
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 PRES-
TIGE Solo is done directly onto the low
voltage terminal strip, reference Fig. 19
page 31 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.
- Consult heat exchanger for maximum
set point of limit.
- For wiring of the limit reference Fig. 19,
page 31, using the external limit/manual
reset terminals on the low voltage termi-
nal 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 7 on pages 93
through 95. For other piping arrange-
ments, contact ACV-Triangle Tube
Technical Support or consult other
approved/recognized design arrange-
ments.
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.
BEST PRACTICE
BEST PRACTICE
NOTICE
16