LAARS NeoTherm NTV1000 - Install and Operating Manual - Manual (Page 78)

LAARS Heating Systems
Page 74
When you set up the Outdoor Reset feature, you
can set the “turning points” on the adjusted setpoint
curve. If you go back to Fig. 9-47, the Outdoor Reset
screen, you see that the system records these values:
Enable -
Enable = Outdoor Reset feature turned on
Max. outdoor temp. -
If the outdoor temperature reaches this value
or above, the system will use the Low Water
Temp value as the setpoint. In the example
shown in Fig. 95, the Max. Outdoor Temp.
is set to 70°F. If the outdoor temperature is
70°F or above, the system will use 100°F
(the Low Water Temp.) as the setpoint.
Min. outdoor temp. -
If the outdoor temperature reaches this value
or below, the system will not compensate
for the outdoor temperature. In the example
shown in Fig. 95, the Min. Outdoor Temp.
is set to 32°F. If the outdoor temperature
reaches 32°F or below, the system will use
the normal Lead/Lag System setpoint (120°F
in this example).
Low water temp. -
If the outdoor temperature reaches the Max.
Outdoor Temp. or higher, the system will
use the Low Water Temp value as the new
setpoint. In the example shown in Fig. 95,
the Max. Outdoor Temp. is set to 70°F. If the
outdoor temperature reaches 70°F or above,
the system will use the Low Water Temp.
value (100°F) as the setpoint.
There is one other part of this system, and it is
located on a different screen:
LL CH setpoint -
On a system set up for Outdoor Reset, this
will be the maximum water temperature
setting. This is located on the main Lead/Lag
Configuration screen.
How to get there – Lead/Lag Master Configuration
Screen
Home Page Lead/ Lag
Screen Lead/ Lag
Screen Lead/ Lag Master
Configuration Screen
Job l - Building automation or multiple
Boiler Control thermostat Demand
(This is a Lead/Lag function – do this once for the whole Lead/
Lag system. Make the connections to the controller set up as the
Lead/Lag Master – usually the Primary controller on Boiler 1.)
1. Supply the controller which is acting as
the Lead/Lag Master (usually the Primary
controller on Boiler 1) with a thermostat
closure from the Building Automation System
or multiple boiler control. Connect to terminals
5 and 6 on TB7.
2. Adjust the Lead Lag Central Heat setpoint.
How to get there – Lead/ Lag Central Heat Setpoint
Home Page Lead Lag
Screen Lead/ Lag
Screen Lead/ Lag Master
Configuration Screen
Line 2 = CH Setpoint
Job m - Building automation or multiple
Boiler 4-20 ma Setpoint Control
(This is a Lead/Lag function – do this once for the whole Lead/
Lag system.)
In this type of installation, the CH Setpoint is changed
or modulated by a source outside of the boiler. The
low limit of the 4-20 mA signal (4 mA) sets the low
limit of the setpoint, and the high limit of the 4-20
mA signal (20 mA) sets the high limit of the setpoint.
1. Supply the controller which is acting as
the Lead/Lag Master (usually the Primary
controller on Boiler 1) with the 4-20 mA input
from the Building Automation System or
multiple boiler control. Connect to terminals 3
and 4 on TB7.
2. On the Lead/Lag Master settings, change the
setpoint source to 4-20 mA.
How to get there – Lead/ Lag Setpoint Control
Home Page Lead/ Lag
Screen Lead/ Lag
Screen Lead Lag Master
Configuration Screen
Central Heat
Setpoint Source = 4-20 mA