Cascade - Lochinvar Armor AWN150PM Installation & Operation Manual

11
Operating information
Monitor external limits
Connections are provided on the connection board for
external limits such as flow switch, gas pressure switches,
and an auxiliary device proving switch.
SYSTEM will shut off the burner and inhibit relighting
whenever any of these external limits open.
Runtime and alarm outputs
The water heater provides dry contacts for indicating when
the water heater is running, and when it is unable to
operate.
Runtime and cycle counting
The control uses two timers to monitor the total hours of
burner operation. One timer monitors the time the water
heater is firing under 50% of rate.
monitors the time the water heater is firing over 50% rate.
The control uses four (4) ignition counters to monitor the
amount of water heater cycles. The first counter counts all
ignitions of the control. The second counter counts only
ignition attempts that have failed. The third and fourth
counters are the same as the first and second respectively,
but can be reset by the installer.
Service reminder
The control can be programmed for service reminder
notification. This notification will become active when
either a set time frame has expired, or a set amount of
running hours or cycles has expired (all adjustable by the
installer). The display will alternate the standard text on the
display screen with Service Due every 5 seconds. The
service reminder notification can be reset by the installer.
Error logging
The control will hold in memory the last 10 error codes as
well as the last 10 turn-off functions. The date and time of
the occurrence will be recorded as well. Only the 10 most
current occurrences will be held in memory.
Water heater temperature regulation
Operating temperature (target)
The SMART SYSTEM control module senses water
temperature and regulates water heater firing and firing rate
to achieve a target temperature. The target temperature can
be set between 60°F and 185°F.
58
High limit operations
When outlet temperature exceeds 200°F, high limit action
occurs. The water heater shuts down until the outlet water cools
The SMART
down and requires manual reset of the control before operation
will resume. To reset control, push the RESET key on the
display.
Low water cutoff protection
1. The SMART SYSTEM control module uses temperature
sensing of both supply and return areas of the heat
exchanger. If the flow rate is too low or either temperature
too high, the control module modulates and shuts the water
heater down. This ensures water heater shutdown in the
event of low water or low flow conditions.
2. A flow switch is factory supplied to provide low flow
The other timer
protection.

Cascade

When multiple water heaters are installed, they can be wired
together in a cascade sequence. A maximum of eight water
heaters can be controlled from a single control. In this
application one water heater would be designated as the Leader
control and all others would be designated as Member controls.
Once the Leader water heater receives a call for heat from a tank
sensor, BMS or tank thermostat, the control will determine what
the set point will be. A fixed temperature set point can be
programmed into the control. See page 57 of this manual to
program the set point.
If the water temperature at the tank or inlet sensor is less than
the set point - differential, then the control will initiate a call for
heat on the Cascade (see the Armor Water Heater Service
Manual for an explanation of the differential). The Leader will
energize the lead water heater on the Cascade. For a new startup
this will be the Leader water heater.
The water heater will fire at its ignition speed and will then
modulate its firing rate to maintain the set point. If the first
water heater reaches 100% of its firing rate, the Leader will
calculate at what point the second water heater could fire at 20%
of its firing rate. At this point, the Leader will fire the second
water heater on the Cascade. For a new startup, this would be the
first Member water heater. The water heater will fire at its
ignition speed and will then modulate its firing rate to maintain
the set point.
Installation & Operation Manual