Crown Boiler PHNTM399, Инструкция по установке и эксплуатации

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X. Operation
A. Overview
1. R7910 Controller
The R7910 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
180 F
Boiler 1
Energy Save On
Max Efficiency On
Standby
i
Status
Help
Adjust
Detail
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 Crown 3501505 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 R7910 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.
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 flow switch and 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 pump and/or the 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 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.