Operating Information; General - Lochinvar Armor AWN150PM Installation & Operation Manual

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Operating information

General

How the water heater operates
The Armor water heater uses an advanced stainless steel heat
exchanger and electronic control module that allows fully
condensing operation. The blower pulls in air and pushes flue
products out of the water heater through the heat exchanger and
flue piping. The control module regulates blower speed to
control the water heater firing rate. The gas valve senses the
amount of air flowing into the water heater and allows only the
right amount of gas to flow.
Control inputs and outputs
Tank thermostat / tank sensor
Either of these inputs will tell the water heater to provide heat to
the water tank. If a tank sensor is connected, the SMART
SYSTEM control will ignore the tank thermostat.
0 - 10VDC input (set point or power)
The Armor water heater 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 with the PC software.
Temperature control
Modulation
The Armor water heater is capable of modulating its firing rate
from a minimum of 20% to a maximum of 100%. The firing
rate is dictated by the hot water draw and various other
temperature limitations.
Night setback
The controller may be programmed to reduce the tank set point
during a certain time each day. A start and stop time can be
programmed for each day of the week.
Flame current support
To prevent nuisance shutdowns when the water heater is firing
at minimum rates, the control will increase fan speed when the
flame signal drops too low.
Installation & Operation Manual
Protection features
Outlet temperature, flue temperature, and temperature
rise limiting
The outlet temperature is monitored by the water heater outlet
temperature sensor. When the outlet temperature exceeds 185°F,
the unit will reduce the fan speed.
temperature exceeds 195°F the control will shut the unit down
until it cools off.
The control module monitors the flue temperature by a sensor
located in the flue exhaust. If the flue temperature exceeds 215°F
the control will reduce the maximum fan speed. If the flue
temperature exceeds 240°F the control will shut the unit down.
The unit will restart automatically once the flue temperature
drops 25°F and the minimum off time has expired.
The control monitors the temperature difference between the
inlet and the outlet sensor. On Models 150 - 500 if this
difference is between 25 - 30°F the control will reduce the fan
speed. If the temperature difference exceeds 30°F the control
will shut the unit down.
On Models 600 - 800 if the temperature difference is between 30
- 35°F the control will reduce the fan speed. If the temperature
differnce exceeds 35°F the control will shut the unit down.
The unit will restart automatically once the temperature
difference has dropped below 25°F (Models 150 - 500) or 30°F
(Models 600 - 800) and the minimum off time has expired.
Freeze protection
DO NOT install the water heater in a room likely to freeze.
The following integral feature of the SMART SYSTEM control
module provides some protection for the water heater.
• The SMART SYSTEM control module provides
freeze-up protection as follows when the water heater
water temperature drops below 45°F:
• Below 45°F, the water heater pump operates constantly.
• Below 37°F, the DHW turns on.
• The water heater and pump will turn off if water
heater water temperature rises above 45°F.
This feature of the SMART SYSTEM control
CAUTION
module does not eliminate the possibility of
freezing.
recognized
maintenance practice to prevent freeze
potential for the water heater.
If the outlet water
The installation must still use
design, installation
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and