LAARS NeoTherm LC NTV1700 - Install and Operating Manual - Manual (Page 84)

LAARS Heating Systems Page 80
9.6 Gateway Connections to a
Building Automation System
NeoTherm LC boilers can be controlled and
monitored through the included Modbus ports. The
Modbus wiring should be completed according
to the instructions in this manual. If alternate
communication protocols are desired, Laars offers
“gateways” to allow BACnet, LON, and other
communications protocols. Signals from a Building
Automation System can be connected to TB10. See
Fig. 120. For additional information on setting up
Modbus and other communication protocols, contact
the factory.
Fig. 120 - BAS Connections
Fig. 121 - Enabling COM2
Enabling Modbus Port 2 -
For this system to work correctly, Modbus Port 2 on
the unit operating as the Lead/Lag Master must be
enabled. From the ‘home’ screen, press the Setup
button to go to the Setup screen. Press the Display
Setup button to go to the Display Setup screen. On
the Display Setup screen, press the COM2 tab to
bring up the setup screen for the COM2 function.
Click the box labeled “Enable COM2 Port.” See
Fig. 121.
9.7 Setup for High Altitude
Operation - NT 1700 Only
(This is an individual function – do this for each of the controls
Use the separate Touch Screen on each boiler.)
When setting up a NT 1700 unit in a high altitude
environment, a low fire adjustment must be made.
The Minimum Modulation rate (RPM) must be
increased from 2100 RPM to 2500 RPM. You will
need to do this in the primary control, then again in
the secondary control on each boiler.
How to get there – Minimum Modulation Rate
Home Page < Select one of the controller icons > NeoTherm
LC Primary (or Secondary) screen < Press Configure button
> Configuration Menu screen < Press line for Modulation
Configuration > Modulation Configuration screen < Go to line
for Minimum Modulation Rate, press box > < System asks you
to login, press Lock symbol at top of screen > Keyboard screen
< Type in installer-level password, then Enter > < Return to line
for Minimum Modulation Rate, press Clear, type “2500”, then
Enter >
Remember to do this for both the primary and
secondary controls on each of the boilers.