Laars LMC Installation and operation instructions manual - page 28
LAARS Heating Systems
Page 28
SECTION 8.
Control Setup and Operation
The Mascot II control is an integrated electronic
control that replaces many of the individual components
found on older appliances. The control acts as the
ignition control, pump control, high limit and cascading/
lead lag control and is setup using the display on the
appliance.
MENU ITEM
DEFINITION
F or C
Selects temperature units
LBTHODLOD Outdoor reset enable/disable -
enables menu items
LBT
Low boiler setpoint during outdoor reset
HOD
High outdoor temperature setpoint
LOD
Low outdoor temperature setpoint
RMT Add
Used for Lead/Lag (follow menus)
LL
Lead/Lag enable/disable - enables menu items
HS
Hysteresis - temp range between on/off cycles
bL
Base Load % - input rate before next boiler fires
Sd
Warm weather shut-down temperature
ASC
Anti short cycle - minutes of delay between
startup
bAC
Future use - Press DONE to exit menu.
PAS
Future use - Press DONE to exit menu.
NOTE:
When enabling/disabling functions, select "Done" and wait 30
seconds before scrolling.
Table 10. Setup Mode Parameters.
MENU ITEM
FUNCTION
RANGE
DEFAULT
Outlet water
Displays the current outlet
55-180°F
120°F
temperature
water temperature & allows
the setpoint to be adjusted
Inlet water
Displays the current inlet
—
—
temperature
water temperature
Delta T
Displays the current
—
—
temperature rise across
the heat exchanger
Stack
Displays the current stack
—
—
temperature
temperature
Outdoor
Displays the current outdoor
—
—
temperature
air temperature
Firing Rate
Displays an indicator of the
—
—
current firing rate based
upon fan RPM. The actual
firing rate may vary.
Table 9. User Mode Menu Structure.
8.1 Display Navigation
The display is divided into three menu structures,
USER, SETUP and DIAGNOSTIC. The menu structure
and variables in each are shown in
Tables 9-11
. Once in
a particular menu structure navigation consists of
pressing the next button to scroll from item to item and
then pressing the up and down arrows to change values.
Once the value is adjusted the NEXT or DONE button
can be pressed. The DONE button returns you to the
Home screen. The NEXT button increments the display
to the next item in the menu structure.
USER mode is the home screen shown on the
control. If the display is not in USER mode wait for the
display timeout period to be reached or press the Done
button to return to the USER menu.
SETUP mode is accessed by holding the up and
down arrow keys simultaneously for 3 seconds.
DIAGNOSTIC mode is accessed by holding the
NEXT button for 3 seconds.
8.2 Ignition Control- Sequence of Events
1.
Call for heat
2.
Safety chain check
3.
Fan starts.
4.
Prepurge timer is started.
5.
Pre ignition time of 2 seconds to check the flame
sensor operation and status.
6.
Trial for ignition period, 4 seconds. The direct
spark ignition switches to constant spark for three
seconds, during which time the gas valve is open.
For the last second of the ignition period direct
spark is de-energized and the flame sensor checks
MENU ITEM
DESCRIPTION
mA
Display the flame sense signal
Alert codes
Displays the current alert code
Lockout code
Displays the current lockout code
Outlet limit
Displays outlet temperature limit
DHW limit
Displays Domestic Hot Water limit setting
DHW actual
Displays Actual DHW temperature
Stack limit
Displays Stack limit setting
Min. firing rate
Displays the minimum firing rate allowed
Min. forced
Allows the user to force the boiler to fire at
firing rate
the minimum firing rate
Max forced
Allows the user to force the boiler to fire at
firing rate
the maximum firing rate
Rate indicator
Displays a indicator of the firing rate based
off of the fan RPM. Actual firing rate may
vary depending upon setup.
Table 11. Diagnostic Mode Menu Structure.
Figure 23. Control Buttons on User Interface.