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Operating information
Installation & Operation Manual
General
How the appliance operates
The Power-fin uses a copper finned tube heat exchanger
to transfer heat from the flue products to the water. An
electronic control module monitors various inputs to initiate
a call for heat. The blower provides air to the burner and
forces the flue products out of the combustion chamber
and into the vent system. The control module regulates
the blower speed to control the firing rate of the unit. The
modulating gas valve monitors the amount of combustion air
being pulled into the blower and regulates the amount of gas
supplied, which then mixes with the combustion air and is
supplied to the burner.
How the control modules operate
The Power-fin boiler is equipped with a SMART TOUCH
control module. The SMART TOUCH control module
receives inputs from boiler sensors and external devices.
The control module activates and controls the blowers and
gas valves to regulate heat input and switches the boiler,
Hot Water Generator (HW), and system pumps on and
off as needed. The user programs the control module to
meet system needs by adjusting control parameters. These
parameters set operating temperatures and boiler operating
modes.
Control inputs and outputs
Enable
This input tells the boiler to provide water for space heating.
Hot Water Generator (HW) tank thermostat
This input tells the boiler to provide water for heating an
indirect HW tank.
0 - 10V BMS input (set point or power)
The Power-fin can be controlled by a Building Management
System (BMS) using a 0 - 10 VDC signal. The control can be
configured by the installer to use this signal to either control
set point or firing rate.
0 - 10V System Pump speed input
When a variable speed system pump is used, and there is a
0 - 10V signal available from the pump speed control, this
signal may be connected to the boiler. Doing so will allow
the boiler to anticipate changes in the BTU’s needed by the
system as the system flow changes, and therefore, help the
boiler to maintain the desired system temperature. Connect
the - input terminal to the COM or - output terminal on the
pump speed control, and the + input terminal to the 0 - 10V
or + output terminal on the pump speed control. Note that
the voltage on these inputs must never go below ground.
HW priority
The SMART TOUCH control allows the connection of a HW
thermostat or tank sensor to the low voltage connection board.
When a tank sensor is connected, the HW thermostat input is
ignored. When a boiler is programmed for HW Normal Mode,
the maximum firing rate can be limited to match the input rating
of the indirect tank coil.
HW / space heating (SH) cycling
If a HW call for heat is received while a space heating call is in
progress, and the HW is in Normal Mode, the control will start
the HW pump and shut the boiler pump off. The system pump
will remain on. For stand-alone boilers, if the space heating call is
still active while the HW call is in operation, the control will wait
for 30 minutes (time adjustable by installer) then it will switch
back to the space heating demand. There is a timer to switch from
space heating to HW and a timer to switch from HW to space
heating. The control will switch back and forth until one of the heat
demands end. This function does not apply to cascade systems.
Controlling sensor
The control module is programmed to use the outlet sensor as the
control sensor by default. If a system supply sensor is connected,
the control automatically uses it as the control sensor. The control
module may be programmed to use the inlet sensor as the control
sensor instead. In this case, the control will use the system return
sensor if it is connected.
Anti-cycling
After a space heating demand has been satisfied, the control will
delay the next space heating call for a set time period (time is
adjustable by the installer). The time delay will be bypassed if the
inlet water temperature drops too far during the delay.
Boiler, system, and HW pump control
When a space heating call for heat starts and no HW call is on, the
boiler pump is turned on. The system pump will turn on also if it is
programmed to do so. If a HW call for heat is on, the boiler pump
will wait to turn on until just before the HW pump turns off. After
the space heating call for heat ends, the boiler pump will run for an
additional period of time.
When a HW call for heat starts, the HW pump is turned on. If a
space heating call for heat is on, the boiler pump will turn off a few
seconds after the HW pump turns on.
Louver
When the boiler needs to control combustion air louvers, connect
a 24 VAC louver relay to the two (2) Louver Relay terminals.
Connect the Louver End Switch to the Louver Proving Switch
input on the Low Voltage Connection Board.
Temperature control
Modulation
The Power-fin is capable of modulating its firing rate from a
minimum of 20% to a maximum of 100%. The firing rate is
dictated by the call for heat (i.e., space heating or hot water
generation), the heating load, ramp delay (if enabled), and various
other temperature limitations.
