Lochinvar Power-Fin Designer's Manual page 42

Designer's Guide Power-fin Water Heater
Power-fin – the components, the design
1. Heat exchanger
The heat exchanger allows system water to flow through specially designed tubes for maximum heat transfer. The
glass lined headers and copper finned tubing are encased in a jacket that contains the combustion process.
2. Heat exchanger access cover
The heat exchanger access cover is a stainless steel door which allows access for service, maintenance, and
removal of the heat exchanger from inside the combustion chamber.
3. Blower
The blower pulls in air and gas through the venturi (see item 5) and injects the fuel/air mixture into the burner, where
they burn inside the combustion chamber.
4. Gas valve
The gas valve allows the proper amount of gas to pass into the burner for combustion. The gas valve on the Power-
fin works under a negative pressure so gas should only be pulled through the valve when the blower is in operation.
5. Venturi
The venturi attaches to the inlet (or suction) side of the blower and generates the negative pressure needed by the
gas valve.
6. Flue sensor
The flue sensor is mounted in the exhaust collar of the unit and monitors the flue gas temperature. If the temperature
in the stack exceeds the maximum temperature the unit will shut down to prevent a hazardous condition. In B9
models, the flue sensor helps to control the amount of modulation to prevent condensation in the stack.
7. Outlet temperature sensor
This sensor monitors the outlet water temperature. If selected as the controlling sensor, the appliance will maintain
set point by adjusting the firing rate of the unit according to this sensor.
8. Inlet temperature sensor
This sensor monitors inlet water temperature. If selected as the controlling sensor, the appliance will maintain set
point by adjusting the firing rate of the unit according to this sensor.
9. Temperature and pressure gauge
The temperature and pressure gauge monitors the outlet temperature of the appliance as well as the system water
pressure.
10. Electronic display
The electronic display consists of 7 buttons and a dual line 32-character liquid crystal display used to monitor the
operation of the heater as well as enter and view the programming of the main control board.
11. Burner
The burner is made of a woven fabric over steel screen construction. The burner uses pre-mixed air and gas and
provides a wide range of firing rates.
12. Water outlet (supply)
The water outlet is a 2 1/2" pipe connection that supplies water to the system with connections for a flow switch (see
#28), a relief valve (see #25).
13. Water inlet (return)
The water inlet is a 2 1/2" pipe connection that receives water from the tank and delivers it to the heat exchanger.
14. Gas connection pipe
The gas pipe connection on this appliance is 1", 1 1/4", or 1 1/2" NPT. To deliver the correct amount of gas volume to
the appliance it may be necessary to have a larger gas line and reduce to the appliance connection size at the
appliance. Please reference the National Fuel Gas Code charts for more details.
15. SMART SYSTEM Control Module
The SMART System Control Module is the main control for the appliance. This module contains the programming
that operates the blower, gas valve, and pumps in addition to other programmable features.
16. Air intake
The air intake pipe allows fresh air to flow directly to the appliance. The air inlet is part of the filter box assembly
where air filtration is accomplished with a standard filter.
17. Line voltage terminal strip
The line voltage terminal strip provides a location to connect all of the high voltage (120 VAC) contact points to the
unit, such as the contacts to control the recirculation pump.
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LOCHINVAR CORPORATION
300 MADDOX SIMPSON PKWY
LEBANON, TN 37090
www.lochinvar.com