IBC Technologies SL 30-175, Инструкция по установке и эксплуатации, Страница: 22 / 78

INSTALLATION AND OPERATION INSTRUCTIONS
1-18
SL 30-175, SL 45-260 MODULATING GAS BOILERS
ensure the pump is rated for the design circulating water temperatures; some
pumps have a minimum water temperature rating above the low temperature
potential of the boiler. Following installation, confirm actual performance by
measuring Δ°T (under high and low flow conditions) after establishing the correct
firing rate .
We require water flow after burner shutdown to utilize legacy heat – this is
significant due to the mass of the heat exchanger (27 Kg) plus its 20L internal
water volume. default software values will run the boiler’s primary pump for up
to 5 minutes (300 seconds) after burner shutdown. secondary pumps can be
set to run up to 5 minutes after burner shutdown (for the last calling load). as
shipped, the default software will run the load 1 pump for 5 minutes to place the
legacy heat where it is useful. any secondary pump can be set to run for 0 – 300
seconds in the heat purge mode. guard against deadheading pumps when all
zone valves are closed (see Section 2.7 Set Up & Load Definition).
the primary pump must be under the control of the boiler to allow pump purge
after burner shut-down.
schematics for several piping layouts are provided, and additional drawings are
available at www.ibcboiler.com. installers shall conform the piping design to one
of the provided configurations to simplify the control application, promote good
loads and flow management.
Propylene glycol solution is commonly used in a closed loop where freeze
protection is required. its density is lower than that of water, resulting in
lower thermal performance at a given flow and pressure. As a rule of thumb,
a 50%:50% solution of propylene glycol and water will require an increased
system circulation rate (gpm up 10%), and system head (up 20%) to provide
performance equivalent to straight water.
1.6.2 basic System Piping Arrangements
Figure 22: Primary/Secondary piping concept with simultaneous setpoint calls
PRIMARY/SECONDARY PIPING CONCEPT
(CLOSELY SPACED TEES)
DHW
FAN COIL
LOW TEMP RADIANT
IBC
SL 30-175
SL 45-260
BOILER
IBC
THIS EXAMPLE:
THREE LOAD, P/S
PUMPING - ALL FOUR
PUMPS SWITCHED
DIRECTLY BY THE
IBC CONTROL
WARNING
Water quality has a significant
impact on the lifetime and
performance of an IBC Boiler
heat exchanger.
Improperly prepared water in
a heating circuit may cause
damage to the heat exchanger
through corrosion or fouling.
Repeated or uncontrolled
water fills will increase the
potential for damage.
High levels of dissolved
solids or minerals may
precipitate out of the fluid
onto the hottest part of the
heat exchanger, impairing
heat transfer and resulting in
overheating and premature
failure. The amount of solids
that may form on the heat
exchanger will depend on
the degree of hardness and
the total water volume in the
system. A high water volume
system with a low hardness
count may cause as much
damage as a system with less
volume and higher hardness,
so it is recommended to treat
water so as to remove all
dissolved solids. Other water
chemistry allowable limits are
as follows:
Acidity pH is to be between
6.6 and 8.5
Chloride is to be less than 125
mg/l
Iron is to be less than 0.5 mg/l
Cu less than 0.1 mg/l
Conductivity is to be less
than 400μS/cm (at 25°C)
IMPORTANT: Ensure that
these limits are acceptable
for the other water-side
components in the system.