Temperature Control; Protection Features - Lochinvar COPPER-FIN II 402 - 2072 Installation And Operation Manual

7
Operating information

Temperature control

Firing rate
Depending upon the model, the Copper-fin II is capable
of staging its firing rate from a minimum of 25% to a
maximum of 100%. The firing rate is dictated by the call
for heat (i.e., space heating or domestic hot water), the
heating load, ramp delay (if enabled), and various other
temperature limitations.
Ramp delay (boiler only)
For systems with lower flow, the SMART SYSTEM can
limit the firing rate (when enabled) when a space heating
call for heat starts, or when switching from a DHW call for
heat to a space heating call for heat. There are six (6) limits
that can be programmed, as well as six (6) time intervals
corresponding to each limit. The sixth limit will also limit
the firing rate for the rest of the call for heat.
Gradient limiting
If during operation of the heater the outlet water temperature
is rising too quickly, the control will reduce the firing rate
to its lowest setting.
Outdoor air reset (boiler only)
With the outdoor air sensor connected, the control module
will calculate the set point based on the programmed reset
curve. The installer can change the slope of the reset curve
by several adjustable parameters. The user can limit the
maximum set point for the system using the space heating
set point.
Boost function (boiler only)
If outdoor air reset is active, and a space heating demand
has been active continuously for a set period of time
(time adjustable by installer) and there has been no DHW
demands, the control may be programmed to increase
the set point by a fixed number of degrees (adjustable by
installer). This process will repeat until the space heating
demand ends, the set point reaches the programmed set
point or a maximum of 20 increases has occurred. Once
the system heat demand is satisfied, the set point will revert
to the value determined by the reset curve.
Night setback
The controller may be programmed to reduce the space
heating (boilers) and tank set points during a certain time
each day. A start and stop time can be programmed for
each day of the week.
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Installation & Operation Manual

Protection features

Outlet temperature, and temperature rise limiting
The outlet temperature is monitored by the boiler outlet
temperature sensor. When the outlet temperature exceeds
230°F (110°C) (boilers) or 190°F (88°C) (water heaters), the
unit will reduce the firing rate. If the outlet water temperature
exceeds 235°F (113°C) (boilers) or 200° (93°C) (water heaters)
the control will shut the unit down until it cools off.
The control monitors the temperature difference between
the inlet and the outlet sensor. If this difference exceeds the
first limit the control will turn off stages. If the temperature
difference exceeds a second limit the control will shut the unit
down. The unit will restart automatically once the temperature
difference has dropped 10°F (6°C) and the minimum off time
has expired.
Freeze protection
DO NOT install the appliance in a room likely to freeze.
The following integral feature of the SMART SYSTEM control
module provides some protection for the appliance only -- not
for the system.
• The SMART SYSTEM control module provides
freeze-up protection as follows when the appliance
water temperature drops below 45°F (7.2°C):
• Below 45°F (7.2°C), the appliance and system pumps
operate constantly.
• Below 37°F (2.7°C), the appliance turns on.
• Appliance and pumps turn off if appliance water
temperature rises above 45°F (7.2°C).
This feature of the SMART SYSTEM
CAUTION
control module does not eliminate the
possibility of freezing. The installer must
still use recognized design, installation and
maintenance practice to prevent freeze
potential for the appliance and system.
High limit operations
When outlet temperature exceeds 240°F (116°C) (boilers) or
210°F (99°C) (water heaters), high limit action occurs. The
appliance shuts down until the outlet water cools down and the
RESET button on the Operator Interface is pressed.