Laars NeoTherm NTH Installation And Operation Instructions Manual - page 25
NeoTherm Boiler
Page 25
5.2.2.5
Adjusting Low Outdoor
Temperature Setpoint
Confirm the display is in
SETUP
SETUP
SETUP
SETUP
SETUP
mode. Scroll to the
LOD
LOD
LOD
LOD
LOD
menu. Use the
UP
or
DOWN
arrows to scroll to the
minimum outdoor temperature. The reset curve will use
it to equate to the maximum water temperature.
5.2.2.6
Lead-Lag
Some facilities have installed or retrofitted
multiple, modular boilers together for various reasons.
Lead-Lag (
LL
LL
LL
LL
LL
) is a boiler sequencing function that
allows multiple NeoTherm boilers to operate as one,
based on load conditions while operating together at
more efficient lower firing rates.
Wiring: Wire Modbus connections J3-4/5/6
(located at top of control board) to connect between
boilers in series. Install remote system sensor on system
loop to be controlled, and wire to TB6-3/4 (labeled
"System Sensor") on the lead NeoTherm boiler.
From the
SETUP
SETUP
SETUP
SETUP
SETUP
mode, enable Lead-Lag function
by choosing one boiler to be the "Leader" (select
LDR
LDR
LDR
LDR
LDR
from menu) and all other boilers on the system as
"Slave" (select
SLA
SLA
SLA
SLA
SLA
from menu). Each boiler in the series
should have a different remote address (
Rmt Add
Rmt Add
Rmt Add
Rmt Add
Rmt Add
). For
example,
Ldr
Ldr
Ldr
Ldr
Ldr
boiler should remain at address #1, first
slave boiler should have address #2, second slave boiler,
address 3, etc. Up to eight boilers may be connected.
A system loop sensor will provide input to only
the lead boiler, which will in-turn communicate to the
slave boilers on the loop. Temperature limiting features
remain in effect for all individual boilers.
HS
HS
HS
HS
HS
- Hysteresis should be set to prevent short
cycling. Default temperature differential is 30°F, but is
application dependent (
HS
HS
HS
HS
HS
value is used only for system
temperature startup / shutdown and not sequential boiler
input modulation control).
bL
bL
bL
bL
bL
- Base Load setting specifies minimum input
rate (50% default) required before activating next boiler.
For example, if lead boiler input rises to 50%, the first
slave boiler will start. Then the present load must be
such to reach 50% of present boiler capacity before any
successive boilers are brought on-line. Boilers will
modulate together (up or down) unless rat drops to
below 20%, in which case one boiler at a time will drop
off-line.
5.2.2.7
Warm Weather Shutdown
Select
Sd
Sd
Sd
Sd
Sd
from the
SETUP
SETUP
SETUP
SETUP
SETUP
mode, and adjust outdoor
temperature at which to disable boiler from CH (Central
Heat) operation.
5.2.2.8
Anti Short Cycle Time
Confirm the display is in
SETUP
SETUP
SETUP
SETUP
SETUP
mode. Scroll to the
ASC
ASC
ASC
ASC
ASC
menu. Use the
UP
or
DOWN
arrows to adjust the
time for the anti short cycle period. The numbers
displayed are in minutes of delay. The anti short cycle
time creates a delay for the specified period of time
between the completion of a call for heat and when the
next call for heat may occur.
5.2.3 Diagnostic Mode
By holding the
NEXT
button for 3 seconds,
DIAGNOSTIC
DIAGNOSTIC
DIAGNOSTIC
DIAGNOSTIC
DIAGNOSTIC
mode allows the user to monitor and control
the items shown in
Table 12
. To scroll through the
menu structure use the
NEXT
button. When a value that
is adjustable has been selected the
UP
or
DOWN
arrow
keys may be used to adjust the setpoint. When
adjustments are complete press the
DONE
button.
5.2.3.1
High Limit
The appliance high limit sensor is located on the
outlet of the boiler. The high limit setpoint is not
adjustable at 200°F.
5.2.3.2
DHW Limit
The DHW maximum temperature setting has been
adjusted at the factory, and can be viewed by entering
the
DIAGNOSTIC
DIAGNOSTIC
DIAGNOSTIC
DIAGNOSTIC
DIAGNOSTIC
mode and scrolling to the
DHW
DHW
DHW
DHW
DHW
menu.
Once in the
DHW
DHW
DHW
DHW
DHW
menu, the maximum temperature will
be displayed. DHW limit is not adjustable.
WARNING
The DHW sensor is NOT a limit device. An anti-scald
device MUST be installed to prevent excessively hot
water from reaching the end user. Failure to install an
anti-scald device may lead to property damage,
personal injury or death.
5.3 Pump Connections
If installed at the factory, NeoTherm energizes the
pump upon a call for heat. Once the call for heat is
satisfied the pump will remain on for the defined pump
overrun time.
NOTE:
System and DHW contacts are dry contacts.
Appropriate voltage must be supplied to the System
and DHW pumps for proper operation.
System pump connections are located on Terminal
Block 5 in the control panel (
see Figure 21
). The system
pump contacts are rated for 120Vac, 7.4 amps. To use
the contacts, power must be supplied on one terminal
with the other terminal wired to the pump or a contact
controlling the pump.
DHW pump connections are located on Terminal
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
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 12. Diagnostic Mode Menu Structure.