U.S. Boiler Company K2 Operating Instructions Manual - page 5
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5. Built-in Safety Control
The Control includes safety controls designed to ensure safe
and reliable operation. In addition to flame safety controls
the Control includes supply water temperature, differential
water temperature, and stack temperature safety limits
and stepped modulation responses. Boiler modulation is
adjusted when required to help avoid loss of boiler operation
due to exceeding limits. Additionally, the Control accepts
the field installation of optional auxiliary safety limits.
6. Outdoor Air Reset
When selected the modulation rate setpoint is automatically
adjusted based on outside air temperature, time of day and
length of demand (boost) settings. Outdoor air “reset”
setpoint saves fuel by adjusting the water temperature of a
heating boiler lower as the outside air temperature increases.
7. Warm Weather Shutdown (WWSD)
Some boilers are used primarily for heating buildings, and
the boilers can be automatically shutdown when the outdoor
air temperature is warm. When outside air temperature is
above the WWSD setpoint, this function will shut down
the boiler, boiler and system pump.
8. Energy Management System (EMS) Interface
The control accepts a 4-20mAdc input from the EMS system
for either direct modulation rate or setpoint.
A factory configured RS485 Modbus interface is available
for Energy Management System (EMS)monitoring when not
used for Multiple Boiler Sequencer Peer-To-Peer Network.
Consult factory for points list or if this interface must be
used in addition to the boiler Peer-to-Peer Network.
9. Circulator Control
The Control may be used to sequence the domestic hot
water, boiler and system circulators. Service rated relay
outputs are wired to a line voltage terminal block for easy
field connection. Simple parameter selections allow all
three pumps to respond properly to various hydronic piping
arrangements including either a boiler or primary piped
indirect water heater. Circulators are automatically run for
a 20 second exercise period after not being used for longer
than 7 days. Circulator exercise helps prevent pump rotor
seizing.
10. Multiple Boiler Sequencer Peer-To-Peer Network
The Control includes state-of-the-art modulating lead-lag
sequencer for up to eight (8) boilers capable of auto rotation,
outdoor reset and peer-to-peer communication. The peer-
peer network is truly “plug and play”. Communication
is activated by simply connecting a RJ45 ethernet cable
between boilers. The Control provides precise boiler
coordination by sequencing boilers based on both header
water temperature and boiler modulation rate. For example,
the lead boiler can be configured to start a lag boiler after
operating at 50% modulation rate for longer than an
adjustable time. The boilers are modulated in “unison”
(parallel) modulation rate to ensure even heat distribution.
i. Operation
A. Overview
1. Sage2.2 Controller
The Sage2.2 Controller (Control) contains features and
capabilities which help improve heating system operation,
and efficiency. By including unique capabilities, the Control
can do more, with less field wiring, and fewer aftermarket
controls and components – improving the operation of both
new and replacement boiler installations.
2. Advanced Touch Screen Display
Home Screen
Boiler status and setup selections are available from an easy
to use, dual color, LCD Touch Screen Display. Over one
hundred helpful information screens are provide to explain
status information and setup functions. In the event of a fault
condition the user is guided by “blinking” touch buttons to
Help screens that explain the problem cause and corrective
action. Operation evaluation and problem-solving is enhanced
by historical capability including graphic trends, lockout
history records as well as boiler and circulator cycle counts
and run time hours.
3. Advanced Modulating Control
The Control modulates the boiler input by varying the fan
speed. As the fan speed increases, so does the amount of
fuel gas drawn into the blower. As a result, a fairly constant
air-fuel ratio is maintained across all inputs. The Control
determines the input needed by looking at both current and
recent differences between the measured temperature and the
setpoint temperature. As the measured temperature approaches
the setpoint temperature, the fan will slow down and the input
will drop. The Control also utilizes boiler return water and
flue gas temperatures to adjust fan speed.
4.
HeatMatch
TM
Software
When the boiler is installed with a Sage Zone Control Panel
(Zone Control) into a multiple zone home the Control uses
a patent pending HeatMatch Software to improve home
comfort, increase component life and save energy. The Sage2.2
Controller with the Zone Control detects active (turned “on”)
zones, totals btu/hrs expected and limits the boiler firing rate
to “match” actual home demand. Instead of simply firing
to 100% in response to a cold supply water temperature the
Control combines heat matching with supply water temperature
control. The result is longer run times, dramatic reduction
in boiler excessive cycling and higher operating efficiency.
Avoiding extra cycling saves customer fuel dollars (pre and
post purge sends heat up stack) and saves wear and tear on
the boiler. Lowering the boiler’s firing rate saves fuel dollars
by increasing the amount of flue gas condensation, always
the goal of condensing boiler installations.